CA1142556A - Inorganic cement grouting system for use in anchoring a bolt in a hole - Google Patents

Abstract

ABSTRACT
A grouting system for use in anchoring a rein-forcing member such as a rock bolt in a hole, e.g., in a mine roof, by the reaction of the mixed components Or an inorganic grouting composition so as to form a hardened grout around the reinforcing member includes a hardenable inorganic grouting composition containing, in a first component, a particulate inorganic cement combined with a liquid which is non-reactive therewith in the form Or a slush or sludgy mass and, in a second component, separated from the first, a liquid which is reactive with the cement, a particulate aggregate such as sand preferably being present in the cement slush and/or the reactive liquid component. A high-early strength grouting system for anchoring a reinforcing member in a hole at a pull strength level Or at least about 175 kg/cm anchoring length within an hour, and usually within 5-10 minutes, includes a hardenable inorganic grouting composition containing an acidic component comprising an acidic oxy phosphorus compound, e.g., H3PO4 or Al(H2PO4)3; a basic component comprising a basic Group II or III metal compound, e.g., MgO; water; and aggregate, e.g., sand; the basic component preferably being in the form of a slush with a non-reactive liquid. The weight of any aggregate present is no more than about 80 percent of the total weight of the composition.
The cement or basic component in slush form and controlled aggregate content impart lubricity to the system for easy insertion and rotation of a reinforcing member, and make the cement or basic component and the combined com-ponents pumpable through small-diameter passageways, while permitting the development of an adequate pull strength Abstract Continued 1A
in the hardened grout formed around the reinforcing member when the mixed components react.
A preferred aggregate, for providing a grout of higher shear strength and facilitating the use of the composition in packaged form, is a non-uniformly graded fine sand, i.e., sand having a deviation of the maximum and minimum particle sizes from the median particle size of more than about ? 20% and having no more than about 10% of its total volume consisting of particles larger than about 600 microns. Of the cements that set by hydration, a pre-ferred cement, on the basis of higher early strength, is one which contains (by weight) about from 20 to 40 percent of 3CaO?3Al2O3?CaSO4 and about from 10 to 35 percent of chemically unbound CaSO4, the remainder being substantially .beta.-2CaO-SiO2. When the reactive liquid component is water containing a particulate aggregate, a small amount of poly-ethylene oxide and/or polyacrylamide preferably is added to the water component as a thickener-lubricant so as to facilitate a bolt insertion into the composition while per-mitting the development of an acceptable shear strength.
The two components preferably are delivered into the hole separately, e.g., from separate feeding con-duits or, more preferably, in separate compartments of a frangible package, which is broken by the penetration of the reinforcing member.

Description

i~2556 PI-0177 Cognate TITLE
Inorganic Grouting Systems For Use In Anchoring A Bolt In A Hole BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to inor-ganic grouting systems and a compartmented package for use therewith in a method of anchoring a reinforcing member in a hole, e.g., in a mine roof, wherein reactive inorganic components are intro-duced into a hole and allowed to react and harden thereln around a reinforcing member so as to fix it firmly in the hole.
Description of the Prior Art Anchor bolts are employed in various fields of engineering, for example as strength-ening or reinforcing members in rock formations and in structural bodies. The bolts are inserted into drill holes in the formation or body, and often are fixed or anchored therein, at their inner end or over substantially their entire length, by means of a reactive grouting composition which hardens around the bolt. When used in a mine roof, bolts grouted in this manner help significantly to prevent mine roof failure. Because unsupported rock .

il'~2556 strata have a tendency to move vertically and laterally, and this motion is what commonly causes the roof to fail, it is important that bolts be installed as soon as possible in a newly e~posed roof and that the required strength provided by the hardening of the grouting composition be developed rapidly, e.g., in a matter of a few minutes, or within an hour or so, depending on the type of mine. Rapid hardening also contributes to the efficiency of the bolt installation operation.
As a practical matter, the hardening or setting time of a bolt grouting composition must be sufficient to allow the reactive components thereof to be mixed and positioned around the bolt in the hole, e.g., at least about 15 seconds, depending on anchoring length, both in the case in which the components are delivered separately into the hole and combined therein and mixed, e.g., by the rota-tion of the bolt, as well as when the components are delivered into the hole in combined and mixed form either before or after bolt insertion. Beyond this necessary working time, the rate at which the composition approaches its ultimate strength should be as high as possible, e.g., for coal mine roof support the grout should attain about 80~ of its pull strength in an hour Gr less, and the ultimate pull strength should be at least about 175 kilograms per centimeter of anchoring length. Thus, the over-riding need in grouting systems for rock bolt anchoring is sufficient working time combined with high ultimate pull strength attained as rapidly s is re~uired for a given use.
Reactive compositions which have been used in rock bolt anchoring include inorganic cement mortars and hardenable synthetic resins, and these have been introduced into the drill holes through a feed pipe, or in cartridged rorm. In the latter case, the reactive components, e.g., a polymerizable resin formulation and a catalyst which catalyzes the curing of the resin, are introduced into the hole in separate cartridges or in separate compart-ments of the same cartridge. A rigid bolt pene-trates, and the.eby ruptures, the cartridge(s) and the package contents are mixed by rotation of the bolt. The grouting mixture hardens around the bolt so as to anchor it in place.
In the case of inorganic cements, the pumping of a prepared cement mortar into a hole after a bolt is in position therein has been des-cribed, as has the driving of a bolt into cement mortar in a hole. In the former case, complete and uniform filling of the space around the bolt is difficult to ensure; and, in the latter case, the bolt has to be installed immediately after the mortar has been introduced, so that it is not feasible to fill a large number of holes with the mortar first and subsequently to introduce the bolts, a more efficient procedure.
Cartridged cement systems for anchoring rock bolts are described in U.S. Re. 25,869, British Patents 1,293,619 and 1,293,620, and German OLS

2,207,076. In these systems the components of a cement mortar are introduced into a drill hole in separate compartments of an easily destructible cartridge. One component of the system, i.e., a cement that sets by hydration, is placed in one of the compartments in the dry particulate state, i.e., as a dry powder or grit; and the other com-ponent, i.e., water, is placed in the other compart-ment. The cartridge is broken and the components are mixed by driving and rQtating the bolt therein.
The cartridged system has the advantage that ~olts can be installed in the holes at any time after the introduction of the reactive components because the components are kept separated until the installation of the bolt. Also, such a system requires no complex pumping equipment at the site of use.
U.S. Re. 25,869 discloses the use of a glass cylinder filled with a dry Portland cement/
sand mixture which has embedded therein a glass capsule containing water and a rapid-hardening agent, e.g., calcium chloride, to shorten the hardening time.
British Patents 1,293,619 and 1,293,620 describe the use of a cartridge consisting of inner and outer rigid brittle tubes having at least one end that is readily frangible, the space between the two tubes containing a mixture of Portland cement and high alumina cement, and the inner tube containing water. The addition of an aggregate, e.g., sand or copper slag, a natural gum and salt compound, and a wetting agent to the water also is disclosed.
In German OLS 2,207,076, the particulate material in one compartment is gypsum, preferably mixed with a strength-enhancing cement, to which an inert filler such as styrofoam may be added. The use of alginates, polyvinyl alcohol, polyacrylic acid, carboxymethylcellulose, and metallic soaps as gelling agents to increase the viscosity of the water in the other compartment also is disclosed.
Although inorganic grouting systems are economically attractive in contrast to resin-catalyst systems, and generally are not plagued with such problems as instability on storage as are resin catalyst systems, cement grouting systems wherein one of the components is a dry cement may present certain 1~2556 ;

difficulties in use, especially when applied to the fixing of bolts in drill holes. When compartmented cartridges are used, the bolt must be inserted into the cartridge and penetrate its full length if the components are to be mixed properly. This insertion is more difficult to achieve with cartridges con-taining a dry cement component. The magnitude of the force required to achieve the necessary insertion may exceed the capability of standard bolting equipment available in the working location, e.g., in a mine.
Also, the insertion force required with such car-tridges may cause the bolt to buckle.
Another problem with the cartridged dry cement component system of the prior art is that the cement component is easily vulnerable to premature hardening should ambient moisture or water from the other compartment penetrate the cartridge seals or packaging material, a situation which could arise on storage or during transportation of cartridges.
Lastly, the prior art bolt-anchoring systems employ-ing inorganic cement are not well-suited for use in the uncartridged form, where compact pumping equipment and accurate metering are desirable to deliver the components to the drill hole.
U.S. Patent 3,324,663 describes the reinforcement of rock formations with a two-component resin composition based on (a) an unsaturated poly-merizable polyester (alkyd) resin mixed with a mono-meric polymerizable ethylenic compound and (b) a cross-linking peroxide catalyst system. ~ water-reactive filler such as Portland cement or p'aster of Paris (S-10 percent of the final composition) is incorporated in either the resin component or the catalyst component, and water is incorporated in the component not containing the water-reactive filler.

11'~2S56 The water-reactive filler and water are used to modify the basic resin/catalyst system, the presence of water during the curing of the resin being disclosed as causing an imperfect cure and minimizing shrinkage. Water-reactive fillers (up to 5 percent) have been disclosed (U.S. Patent 2,288,321) to shorten the curing time of alkyd resins by reacting with the water formed during curing.
In the grouting system of U.S. Patent

3,324,663, the reactants essential for the for~ation of a hardened grout are totally organic, i.e., an alkyd resin and a liquid ethylenic monomer, and they are cartridged together in the same compartment, lS i.e., premixed, the resin being dissolved in the ethylenic monomer and reacting therewith when the separately packaged catalyst is mixed in. Only about 5-10 percent of the total composition is water-reactive filler. The preponderance of resin and catalyst in this system, and the basic resin-curing reaction that occurs, over-ride and obscure any possible secondary reaction involving the water-reactive filler.
With regard to specific inorganic grouting compositions, cements that set up by hydration are the best-known. However, it is known that certain oxide/phosphate compositions can react extremely rapidly to form hard products. These compositions contain high-surface-area magnesium oxide, and/or monoammonium phosphate. The reaction with phosphoric acid also has been reported to be extremely rapid. While rapid reaction of the components of a grouting composition for anchoring rock bolts for coal mines is a desirable property (provided that the composition does not set before ll ~Z556 it can be mixed and emplaced), it is essential that compositions for this use develop high strength early and attain a high ultimate strength within a reasonable period of time, e.g., in an hour or so, to provide an umbrella of safety in a mine roof.
The prior art does not describe or suggest oxide/
phosphate grouting compositions that meet these requirements, e.g., compositions that permit suffi-cient time for emplacing and mixing yet attain a pull strength of at least about 175 kilograms per centimeter of anchoring length in an hour or less.
The hardening reaction that occurs when magnesium oxide and phosphates are combined has been employed for various purposes, e.g., to produce a lS binder system for foundry aggregate or refractory materials, to patch or repair cracks in roadways, etc. In these systems the reactants have a low rate of reaction, and are characterized by a long setting time (long pot life or working time) and slow strength development, usually over a period of days.
Long pot life allows the mixture of reactive com-ponents to be shaped, e.g., by casting, and permits the performance of large jobs with a single mix.
For example, U.S. Patent 3,923,534 discloses refractory compositions in which a magnesia of low reactivity (fused or hard-burnt magnesia) is used as a setting agent in combination with water and a water-soluble aluminum phosphate binding agent for a re~ractory filler such as silica or alumina. The wet refractory composition is said to be useful in concrete mixes, as a mortar or grouting, or as a castable composition. Low-reactivity magnesia is used in a minor amount relative to the aluminum phosphate, and the binding agent is a complex phosphate containing aluminum and phosphorus in a 1/1 ratio. These compositions set in hours or even days, allowing large mixes to be used but consequently providing no significant supporti~e strength over such periods. In addition to lacking early strength, the described compositions develop very little mechanical strength on standing at room temperature even for several days after setting, and require heating, for example, heating in use, to attain a useful mechanical strength.
U.S. Patent 3,923,525 relates to binder compositions for foundry aggregate, the binder system being obtained from an aluminum phosphate containing boron, an alkaline earth material, and water. The composition of the aggregate-binder foundry mix is such as to allow it to be molded or shaped and there-after cured to form a porous self-supporting structure having good collapsibility and shake-out properties.
Only a small amount of binder is used, generally less than about 10 percent, and frequently within the range of about 0.5 to about 7 percent, by weight, based on the weight of the aggregate. Most often, the binder content range by weight is from about 1 to about 5 percent of the aggregate weight. This is sufficient to allow the binder to be distributed on the aggregate particles, and the coated particles to be molded into the desired shape. These foundry mixes require 1 to 4 hours to cure, and the cured shapes are weak enough to be collapsible and readily broken down for removal from a casting.
The method of patching described in U.S.
Patent 3,821,006 employs a two-component system of an inert particulate aggregate such as sand and a reactive mixture of an acid phosphate salt and magnesium oxide particles of the "dead-burned" type.
Acid phosphate salts disclosed are monoammonium 55~
g ph~spAate, monosodium phosphate, anà monomagnesium phosphate. None of the disclosed compositions made from these salts hav~ the high early strengths required for rock bolt anchoring in mine roofs. For example, a composition made from monomagnesium phosphate is reported to have developed a compressive strength of only 29 kilograms per square centimeter after 2 hours, and 60 kilograms per square centimeter after 24 hours.
Ammonium phosphate as a binder for magnesium oxide is also described in U.S. Patents 3,960,580, 3,879,209, and 3,285,758. The cements based on magne-sium oxide and dry, solid monoammonium phosphate (or an aqueous solution of ammonium polyphosphates) of U.S. Patent 3,960,580 contain an oxy-boron compound such as sodium borate to extend their setting time.
The compressive strength of these cements even after 2 hours is low, and their maximum strength is not attained for many days. U.S. Patent 3,879,209 des-cribes a process for repairing roadways, etc. with a composition comprising a magnesia aggregate wetted with a solution of ammonium phosphate containing ortho-phosphates, pyrophosphate, and polyphosphates, the latter including tripolyphosphate and higher polyphos-phates. This composition also develops strengthslowly, i.e., over a period of days. The ammonium component is described as essential for this composi-tion, as phosphorus oxide components alone, such as phosphorus pentoxide, are disclosed as not giving the desired results. The same ammonium phosphate solution is described in U.S. Patent 3,285,758, which also mentions the unsuitability of phosphoric acid and magnesium phosphate as well.
German OLS 2,553,140 describes a process for producing a cement by reacting aqueous orthophosphoric S~
acid with a chemical combination of oxides such as magnesium orthosilicate (2MgO-SiO2). The cement com-positions described have long setting times (9-90 minutes) and their compressive strengths are measured usually after one month.
SUMMARY OF THE INVENTION
The present invention provides improved grouting systems for use in anchoring a reinforcing member in a hole by the reaction of the mixed com-ponents of a hardenable inorganic grouting compositionso as to form a hardened grout around the reinforcing member, the improved systems having, in one case, a cement component in slush form to impart lubricity to the grouting composition for easy insertion and rotation of a reinforcing member, and, in another case, a high-early-strength phosphate grouting composition, particularly suitable for use in coal mine roofs, that achieves a pull strength level of at least about 175 kg/cm anchoring length within an hour, and usually within 5-10 minutes.
In one embodiment of the invention, an inorganic grouting system includes a composition comprising controlled amounts of a first component (a) comprising a slush or sludgy mass of a particu-late inorganic cement, e.g., a cement that sets byhydration, and a liquid, such as a hydrocarbon, which is non-reactive therewith, and a second component (b), separated from the first, comprising a liquid, e.g., water, which is reactive with the inorganic cement in the first component, the inorganic cement constituting more than 10 percent of the total weight of components (a) and (b), and components (a) and (b) being adapted to be brought together and intimately mixed so as to react rapidly to form a hardened grout of sufficient strength to ll~Z556 firmly anchor the reinforcing member to the wall of the hole. A particulate aggregate such as sand preferably is present in one or both of the com-ponents in an amount such as to constitute about from 20 to 80 percent of the total weight of components (a) and (b). A non-uniform fine sand is most preferred. In this system, the grouting com-position preferably is forced into an annulus formed between the reinforcing member and the wall of the hole by the introduction of the reinforcing member into the grouting composition before any substantial hardening of the composition has occurred, the mixed components of the composition reacting in the annulus to form a hardened grout.
In a method of anchoring a reinforcing member in a hole by means of this improved grouting system, (1) two components of a hardenable inorganic grouting composition are delivered into the hole in controlled amounts, the first of these components, (a),comprising a slush of a particulate inorganic cement and a liquid which is non-reactive therewith, and the second, (b), comprising a liquid which is reactive with the inorganic cement, the inorganic cement constituting more than 10 percent of the total weight of compo-nents (a) and (b); and (2) a reinforcing member isintroduced into the grouting compos tion in the hole before any substantial hardening of the composition has occurred, whereby grouting composition is forced into an annulus formed between the reinforcing member and the wall of the hole; components (a) and (b) being delivered into the hole in a separated or freshly brought-together condition and intimately mixed whereby they react rapidly around the reinforc-ing member to form a hardened grout of sufficient strength to firmly anchor the reinforcing member to ll'~Z~6 1~
the wall of the hole. Preferably, the two components are delivered into the hole separately, most prefera~ly by virtue of their being maintained in a frangible compartmented package adapted to be inserted into the hole and subsequently broken therein by the penetration of the reinforcing member therethrough, and the components are brought together and mixed by rotation of the reinforcing member.
The invention also provides such a package containing (a) in a first compartment, a slush or sludgy mass comprising a particulate inorganic cement in a liquid which is nonreactive therewith, and (b) in a second compartment, separated from the first, a liquid which is reactive with the inorganic cement in the first compartment, the inorganic cement constituting more than 10 percent of the weight of the total package contents. A particulate aggregate such as sand preferably is present in the first and/or second com-partments in an amount such as to constitute up to about 80 percent of the weight of the total package contents.
In a preferred grouting system and anchoring method of the invention, which finds particular use in the reinforcement of mine roofs wherein the grouting composition has to set up fast enough to provide high strength in a very short time, grouting compositions are employed which harden relatively rapidly, e.g., compositions containing calcined gypsum or Very High Early Strength cement (described in U.S. Patent 3,860,433) in the first component and water in the second component, or wherein the cement in the first component is an alkaline earth metal oxide or hydroxide and the second component contains a phosphoric acid or phosphate solutior The term "inorganic cement" as used herein ll'~Z5S6 to describe the particulate solid reactant in the first component or package compartment denotes a particulate inorganic composition that sets up and hardens to a strong, dense monolithic solid upon being mixed with a liquid and allowed to stand.
The term includes hydraulic cements, i.e., those that are capable of setting and hardening without contact with the atmosphere due to the interaction of the constituents of the cement rather than by the evaporation of a liquid vehicle or by reaction with atmospheric carbon dioxide or oxygen. Examples of such cements are Portland cements, high-alumina cements, pozzolanas, and gypsum plasters, which set up when mixed with water; lead oxide, which sets up when mixed with glycerin; as well as the more rapid-setting metal oxide or hydroxide com-positions, e.g., magnesium oxide, which set up rapidly when mixed with phosphoric acid or phos-phate solutions.
The term "slush" as used herein to describe the first component of the grouting composition denotes a solid-liquid combination of mud-like or sludgy consistency. The term includes solid-liquid combinations of varying degrees of mobility, but in all cases denotes combinations that are readily pumpable.
The term "liquid" as used herein to des-cribe the second component of the grouting compo-sition which is reactive with the inorganic cement in the first component is used in the conventional sense to denote single-phase materials as well as solutions. Also, the reactivity of this liquid with respect to the cement may be produced in situ when the components are brought together, as will be described hereinafter.

l ~ ~Z~ i~6 The nonreactivity of the liquid in the slush which constitutes the first component or which is present in the first package compartment refers to the substantial lnertness of this liquid with S respect to the solid cement and other materials present therein. Such liquid may, however, be reactive with a material in the second component or compartment, and may have some influence on the setting time and ultimate strength of the grout.
In another embodiment, the present inven-tion provides a high-early-strength phosphate grouting system for use in a hole in combination with a reinforcing member wherein a hardened grout is formed around the reinforcing member in the hole by the reaction of the mixed components of a hardenable inorganic grouting composition, said grouting compo-sition comprising (a) an acidic reactive component comprising at least one acidic oxy phosphorus compound selected from the group consisting of phosphoric acids, e.g., H3PO4, anhydrides of phosphoric acids, e.g., P2O5, and salts of phosphoric acids with multivalent, preferably trivalent, metal cations, preferably Al(H2Po4)3;
(b) a basic reactive component comprising at least one particulate basic compound of a Group II
or Group III metal capable of reacting with the oxy phosphorus compound in the presence of water to form a monolithic solid, preferably an alkaline earth metal compound selected from the group consisting of magnesium oxide,magnesium hydroxide, magnesium silicate, magnesium aluminate, and calcium aluminate;
and tc) an aqueous component;
3~ these components being present in or outside a hole in a separated condition such that any substan.ial hardening reaction between the basic and acidic components is prevented, and when present outside the hole being adapted to be delivered into the hole separately or in a freshly combined condition; the basic metal compound(s) having a particle surface area of about from 0.1 to 40, preferably less than about 30, square meters per gram and constituting about from 5 to 35 percent of the total weight of the grouting composition, with the proviso that when the surface area is less than 1 square meter per gram more than about 95 percent of the particles pass through a 200 mesh screen (U.S. Standard Sieve Series);
the ratio of the moles of the basic metal compound(s) to the moles of phosphorus pentoxide on which the oxy phosphorus compound is based being in the range of about from 2/1 to 17/1; the amount of water present in the composition constituting about from 3 to 20 percent of the total weight of the grouting composi-tion; a particulate aggregate being present in thecomposition in an amount such as to constitute about from 30 to 70 percent of the total weight of the composition; and the components, when mixed, reacting without the application of heat thereto to form a hardened grout having a pull strength of at least about 175 kilograms per centimeter of anchoring length within an hour.
In a preferred embodiment, the acidic reactive component and at least a portion of the aqueous component are combined together in the form of an aqueous solution or mixture of a phosphoric acid or a phosphoric acid salt, and this solution or mixture is kept separate from the basic reactive component until use.
In this high-early-strength system, use of the reactive components in the form of a slush also is desirable to achieve lubricity in the system for the easy insertion and rotation of a reinforcing member, and to make the component pumpable through small-diameter passageways. Hydrocarbons, polyols, and water are suitable slush-forming liquids.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing, which illus-trates specific embodiments of the compartmented package and inorganic grouting systems o~ the inven-tion, FIG. l is a perspective view of a portion of a compartmented package of the invention, which package has been cross-sectioned in the transverse direction so as to reveal more fully the internal structure thereof; and FIG. 2 is a plot of shear strength vs.
time of a cement-water system of the invention.
DETAILED DESCRIPTION
In a method and system of this invention, an inorganic cement, e.g., a cement that sets by hydration or a metal oxide, is maintained in the form of a slush or sludgy mass together with a liquid with which it does not react, e.g., an inert nonaqueous liquid, preferably a hydrocarbon, in the case of a cement that sets by hydration; and the slush is brought together and mixed, preferably in a drill hole, with a reactive liquid, e.g., water in the case of a cement that sets by hydration, and allowed to react in the hole around a reinforcing member. Cement in slush form has several advantages over the dry cement used in previous rock bolt packages. First, the nonreactive liquid imparts lubricity to the cement so that, when the two components of the grouting composition are packaged ll~Z5S6 in a compartmented cartridge, a bolt can be inserted into the cartridge easily and rapidly. Also, the nonreactive liquid, if substantially immiscible with the reactive liquid, helps to reduce tne possibility of the premature setting of the cement as a result of contact with the reactive liquid or its vapors, e.g., ambient moisture, during storage or handling, thereby affording a longer shelf life to the car-tridged system. In addition, use of the cement in slush form enables the cement component to be metered accurately and handled in compact pumps for ease of packaging in high-speed form-fill machinery as well as for on-site feed operations. The cement component in slush form also is advantageous in that it is adapted to be delivered intermittently in relatively small quantities as is required for bolt anchoring in holes.
The combining of the inorganic cement with a nonreactive liquid in accordance with one embodi-ment of the present invention, while effectivelyisolating and fluidizing the cement prior to use, surprisingly does not interfere with the interaction of the cement and reactive liquid after the grouting components have been mixed, relatively short setting times, rapid strength development, and high ultimate strengths being attainable despite the initial presence of the nonreactive liquid around the particles of cement in the slush. The fact that the present slush system provides the rapid setting and strength development that is so important for mine roof support is indeed unexpected when consideration is given to the slush form of the cement used, and the behavior of cement-oil combinations in such processes as the cementing of wells, well casings, or earth formations. For example, in the process 11~25~6 for sealing off water-bearing formations adjacent to oil- or gas-bearing for~ations, known as "squeeze cementing", and described, for example, in U.S. Patent 2,800,363, a cement slurry is pumped into a well until it is adjacent the water-bearing formation, and is held there in a static condition for about five minutes ("hesitation step") to allow water from the water-bea~ing formation to come into contact with the slurry. Then high pressure is exerted on the slurry to squeeze it into the hydro-carbon-bearing and water-bearing formations. The slurry in the water-bearing formation hardens to selectively seal off that formation. In the "squeeze cementing" process and the well-cementing lS process of U.S. Patent 2,878,875 oil or a water-in-oil emulsion has been used in place of water in the cement slurry in order to delay the setting time of the cement. The development of strength in the cement in the described well-sealing process has been reported to require several days' time, an indica-tion that cement-oil slurries should be avoided in processes requiring a rapid setting of the cement.
In the high-early-strength phosphate grouting system of the invention, ~articulate materials in the grouting composition, e.g., the basic metal compound, aggregate, or the oxy phos-phorus compound, may be present in the dry state, but preferably they are present in the form of a solution, slurry, or slush with a liquid with which they are nonreactive to any substantial degree. If water is kept separate from the oxy phosphorus compound, the latter and any aggregate which may be combined therewith form a slurry or slush with a nonaqueous liquid, preferably a hydrocarbon.
Preferably, however, in the acidic component, ~l~ZSS6 phosphoric acid or a metal phosphate is present in aqueous solution or as a slurry or slush with water, which slurry or slush may also contain aggregate. The basic metal compound and any aggregate present therewith preferably form a slurry or slush with a nonaqueous liquid such as a hydrocarbon or polyol, or with water or a water-containing liquid, water being used if the oxy phosphorus compound is separate from the basic metal compound and if the basic metal compound is sufficiently nonreactive with water that the basic component is not rendered resistant to bolt pene-tration by the occurrence of a hardening reaction therein. Magnesium oxide, for example, can be used in a slush with water or a water-containing mixture such as an aqueous glycol. A reaction may begin to take place between the oxide and water after some time depending on such factors as the calcination or fusion temperature of the oxide, the oxide/water ratio, oxide particle size, storage temperature, etc. This produces magnesium hydroxide, also a basic metal compound as defined herein for use in the basic reactive component. Thus, in a packaged system some change in the consistency of the basic component may be noted after a certain period of time, e.g., after about several hours to several days, when magnesium oxide and water are present therein, but this does not involve hardening to the degree that bolt penetration becomes difficult. Also in a system wherein a freshly made magnesium oxide/water component is pumped into a hole, bolt insertion and reaction with the acidic component would occur before hydration of the oxide. Thus, in the sense defined above, water is a substantially nonreactive Z~
~ o slush-forming liquid for magnesium oxide.
A wide variety of liquids can be used as slush-forming liquids in the grouting compositions.
The specific choice in any given case will be made on the basis of the nature of the particulate ingredient, usually the cement or basic metal com-pound, any effect the particular liquid may have on the setting and strength-development time, and the cost of the liquid. Liquid hydrocarbons and mixtures containing such hydrocarbons are particularly advantageous from the point of view of setting time as well as cost, and therefore are preferred. A
substantially nonvolatile liquid is preferred to assure stability under varying conditions of storage and use. For this reason, liquids boiling above about 25C at atmospheric pressure are preferred.
Thus, preferred hydrocarbon slush-forming liquids are 5-25 carbon atom aliphatic hydrocarbons such as hexanes, heptanes, and octanes; and aromatic hydro-carbons such as benzene and alkyl benzenes, e.g.,toluene and xylene. Aromatic or aliphatic hydrocar-bon mixtures such as gasoline, naphtha, kerosene, paraffin oil, diesel fuel, fuel oils, lubricating oils, vegetable oils, e.g., linseed, tung, cottonseed, corn, and peanut oils, and crudes such as petroleum and shale oil also can be employed. For use in coal mines, the liquid in the slush must have a flash point above 38C and should be low in volatile aromatics.
Although low-viscosity slush-forming liquids are preferred, thick liquids such as medium- or high-viscosity process oils, asphalt, grease, e.g., hydro-carbon oils thickened with soaps or other viscosity modifiers; animal fats, e.g., lard; and hydrogenated vegetable oils also can be used alone or combined with ll~ZS.~6 lower-viscosity liquids.
The slush-forming liquid also can be an alcohol, e.g., methanol, isopropanol, butanol, sec-butyl alcohol, amyl alcohol, a polyol such as glycol, or glycerol; a ketone, e.g., acetone or methyl ethyl ketone; cellosolve; an ester, e.g., dibutyl phthalate or acetyl tributyl citrate; dimethyl sulfoxide; or dimethylformamide; but the setting time of grouts made from slushes with these compounds may be much longer than that from slushes with hydrocarbons.
A particulate aggregate, preferably sand, may be present in a controlled amount as a filler in one or both of the components of the grouting com-position, e.g., cement/water or basic/acidiccomponents. In general, aggregate greatly enhances the strength of the hardened grout and also reduces the amount of cement or basic metal compound required.
Other aggregate materials which can be used include particles of competent rocks or rock-forming minerals such as granite, basalt, dolomite, andesite, feldspars, amphiboles, pyroxenes, olivine, gabbro, rhyolite, syenite, diorite, dolerite, peridotite, trachyte, obsidian, quartz, etc., as well as materials such as slag, cinders, fly ash, glass cullet, and fibrous materials such as chopped metal (preferably steel) wire, glass fibers, asbestos, cotton, and polyester and aramide fibers. Sands having different particle shapes and sizes can be used. Because of the need to be packed in a narrow annulus, the particles should have a minimum dimen-sion no larger than about 3 mm. Mixtures of dif-ferent aggregates also can be used.
For a given system, the shear strength of the hardened grout increases with increasing aggregate content up to about 60-70 percent by weight based on the total weight of the grouting composition. At the same time, however, mixing of the components becomes increasingly difficult as the aggregate content increases. Also, too high an aggregate content, e.g., 90 percent or more based on the total weight of the grout results in a friable, impact-sensitive product whlch is of no use for anchoring a reinforcing member in a hole.
Therefore, while an aggregate content of up to about 80 percent can be employed, a content above about 70 percent is not preferred on the basis of ease of mixing and because there is little if any shear strength increase to be gained by exceeding 70 percent. Also, an aggregate/cement weight ratio in the range ofabout from 1/1 to 4/1 is preferred.
Usually at least about 20 percent, and preferably at least about 40 percent, of the total weight of the grouting composition will be aggregate.
The manner in which the aggregate is distributed between the reaction components has no significant effect on the shear strength of the hardened grout. Thus, 100 percent of the aggregate can be in the cement slush or basic component, or 100 percent in the component separated therefrom.
Alternatively, aggregate can be distributed in any other proportions, e.g., 1/1, between two separated components. The specific aggregate distribution in any given case usually will be selected on the basis of that which glves a desired viscosity balance and ease of mixing. In a system in which the components are pumped and mixed at the site of use, it may be more convenient to include the aggregate in only one of the components.
In the inorganic grouting systems of this invention a 2referred aggregate in the grouting composition is non-uniform or graded sand, i.e., sand having, in a size cut which includes 90 percent or more of the particles, maximum and minimum sizes that deviate by more than about 20 percent from the median particle size of the cut. It has been found that graded sand produces bolt-anchoring grouts having higher shear strengths than those made from composi-tions containing uniform sand. Inasmuch as graded sands having a 30 percent or more particle size deviation are commonly available, these often will find use in the present system. Although it is not intended that the invention be limited by theoretical considerations, it is believed that the advantageous effect of graded sand in the composition, as contrasted to uniform sand, may be related to a better distribu-tion and packing of sand particles.
In the present grouting systems, the sand preferably is substantially free, and in any case contains no more than about lO, and preferably no more than about 5, percent by volume, of particles larger than about 600 microns. Compositions contain-ing more particles of this size have to have a higher liquids/solids ratio to facilitate pumping, e.g., during packaging operations, and the liquid content necessary for pumpability may result in a weaker grout.
With particles larger than about 600 microns, there is a greater likelihood that the sar.d particles will be able to pierce through film cartridges of the grout, especially at the ends of the cartridge where the film is gathered together and held in place by a metal clip, thus resulting in leakage. Larger than 600-micron particles also are deleterious to the composition in that they make the insertion of a bolt difficult. Such particles have a greater tendency to settle out of a slush, slurry or liquid, thereby causing cartridged grouts to be harder and st~ffer in one area than in another, and making it difficult for a bolt to be inserted therein. Bolt insertion also is easier when the sand has round, rather than jagged, particles, and therefore round-particle sands are preferred.
When the components of the grouting compo-sition used in the phosphate grouting system of the invention are combined and mixed, the reactive materials therein react rapidly around a reinforcing member to form a hardened grout of sufficient strength to firmly anchor the reinforcing member in a hole in rock strata so as to provide supportive strength to the strata. In quantitative terms, rapid reaction, in this case, means that the phosphate grouting com-position hardens in less than 30 minutes, usually in about 1-2 minutes, and reaches at least about 80% of its ultimate pull strength in less than 30-60 minutes, usually in less than 10 minutes. Firm anchorage means that the ultimate pull strength of the hardened grout is at least about 175 kilograms per centimeter of anchorage length.
The rapid attainment of high pull strength that characterizes the present phosphate grouting system depends on a unique combination of features of the grouting composition, including the surface area and content of the particulate basic metal compound(s), with respect to the total grouting composition and also with respect to the oxy phosphorus compound(s) the water content, the aggregate content, and in a preferred case, the presence of an oxy phosphorus compound (trivalent metal salt of phosphoric acid) that forms a cross-linked ?olymeric network in the hardening reaction. The reactive entity in the ll~Z556 acidic component is a phosphoric acid or an anhydride thereof, or an acid salt of a phosphoric acid with a multivalent, preferably trivalent, metal cation. This entity reacts with the reactive entity in the basic component which is a basic Group II or III metal compound that is capable of reacting with the phosphoric acid or an anhydride or salt thereof to form a monolithic solid. Such compounds include, for example, alkaline earth metal oxides and hydroxides, e.g., magnesium oxide, magnesium hydroxide, and calcium oxide; aluminum oxide and hydroxide; ferric hydroxide; alkaline earth metal aluminates, e.g., magnesium aluminate and calcium aluminate; and magnesium silicate.
lS Magnesium oxide and hydroxide are preferred on the basis of availability. Aluminum oxide, e.g., A12O3 3H2O, desirably is used in mixture with magnesium oxide or hydroxide, especially when the oxy phosphorus compound is phosphoric acid, H3PO4.
With such mixtures, up to about 13%, and preferably about from 5 to 7% of the grouting composition, is aluminum oxide.
When the acidic, basic, and aqueous com-ponents are combined and mixed, the phosphoric acid or phosphate reacts with the particulate basic metal compound in the presence of the water to form a hardened structure wherein the particles of aggregate and any unreacted portions of the par-ticles of the basic metal compound are bound together. It has been found that monovalent salts of phosphoric acid, e.g., the ammonium phosphates which figure prominently in the prior art on patching systems, etc., do not develop the early pull strength required for bolt anchoring, and it is believed that this shortcoming is due, at least 25~6 in ?art, to the inability of such salts to form a three-dimensional polymeric network crosslinked by a multivalent metal ion, e.g., Al 3. ~or this reason, salts of phosphoric acids with trivalent metal cations, e.g., Al 3, are preferred phosphoric acid salts in the acidic component. Phcsphoric acid (and P2O5), and acid alumlnum salts thereof, espe-cially the common aluminum dihydrogen ?hosphate and AlH3(PO4)2-H3PO4, are most preferred on the basis of availability.
In the present system, the grouting composition is in its pre-mixed form, and for this reason the acidic, basic, and aqueous components are present in a separated state. Separation of these components is such that one component is excluded from the presence of the other two, which in turn may be together or also separate. In most cases, it will be more convenient, and therefore preferred, to have the phosphoric acid or phosphate present in its hydrous form, i.e., as an aqueous solution or slurry, and in such cases the combined acidic and aqueous components will be maintained separate from the basic component, which can also contain water and/or a nonaqueous liquid. Alternativel~, a sub-stantially anhydrous acidic component, e.g., onecontaining P2O5, can be combined with a substantially anhydrous basic component, and these combined com-ponents kept separate from the aqueous component; or the basic and aqueous components can be combined and kept separate from the substantially anhydrous acidic component. In both of the latter cases, the sub-stantially anhydrous components can be slurries or slushes with nonaqueous liquids.
The particulate basic metal compound, e.g., magnesium oxide, has a surface area in the range of up to about 40 square meters ~er gram, and con-stitutes about from 5 to 35 percent of the total weight of the grouting composition. Grouts having less than about 5 percent OL the basic metal compound do not develop a sufficiently high ultimate pull strength regardless of the setting time. A
preferred minimum is about 8 percent. There appears to be no advantage in exceeding a basic metal com-pound content of about 35 percent, and on an econo-mical basis more than about 25 percent generally willnot be used. These percentages refer to the total of all such reactive basic metal compounds present.
The preferred basic metal compound has a surface area of less than about 30, and most prefer-ably 1 to 20, square meters per gram. This meansthat the preferred magnesium oxide is the so-called "chemical grade" magnesium oxide, prepared by calcining magnesium carbonate at temperatures in the 900-1200C range. Calcined-grade tsurface area gen-erally well below 1 square meter per gram) and fused(surrace area below about 0.1 square meter per gram) magnesium oxide also can be used, however. For a given concentration of the basic metal compound, the selected surface area thereof should be sufficiently low to assure the necessary working time (e.g., about 15-45 seconds to allow insertion of a bolt into the grout and mixing), but sufficiently high to give a hardened grout of a desired strength in the desired time. Generally, this means that high concentrations are used with low surface areas and vice versa. With low-surface area compounds, e.g., below about 1 square meter per gram, more than about 95 percent of the particles should pass through a 200-mesh screen (U.S. Standard Sieve Series) to assure an acceptable reaction rate. High-surface-5~6 28area i~gO preferably is used with aluminum phosphate.
High early strength also requires that the basic metal compound concentration be sufficiently hish with respect to the amount of phosphoric acid (or its anhydride) or metal phosphate present in the acidic component. The molar ratio, for example, of the basic metal compound in the oxide form to the oxy phosphorus compound in the form of P2O5 should be at least about 2/1, preferably at least about

4/1. Generally, there is no advantage to exceeding this ratio to any large degree, e.g., above about 17/1, inasmuch as a cheaper filler can be used to increase the solids content without deleterious effect.
As was mentioned previously, a phosphoric acid or a metal phosphate preferably will be present in the hyd~ous form, i.e., as an aqueous solution or slurry, and in this embodiment the aqueous component will, at least in part, be found combined with the acidic component. In this case, the basic component must be maintained separate from the acidic component, and may or may not contain water.
Water is needed in the grouting composition so that the acidic oxy phosphorus compound will be in the form of a well-dispersed system which allows for mobility of ions. At least about 3 percent of the total weight of the grouting composition will be water, larger concentrations being used with compositions containing larger amounts of oxy phosphorus compound.
However, the water content of the composition has to be controlled so as not to exceed about 20 percent by weight, or the rate of strength development will be deleteriously affected. Accordingly, the concentration of aqueous phosphoric acid or aqueous metal phosphate in the acidic component is at least about 60 percent 11~2S56 by weight. This concentration can be much higher, e.g., when water is also present in the basic com-ponent. Supersaturated aluminum phosphate solutions and the solid-liquid mixtures which result when crystallization ta.~es place from these metastable solutions are preferred over less concentrated solutions because they produce stronger grouts.
The hardened grout produced around the reinforcing member in the method of this invention forms as a result of the reaction between inorganic reactants. Organic resin-curing systems are not required, and the reactants which undergo a hardening reaction therefore are substantially all-inorganic. The development of strength in the hardened grout sufficient to anchor a bolt securely in place in a hole in a mine roof, and provision of the components in a form such that they can be delivered and mixed conveniently, require a balance of the content of inorganic cement, slush-forming liquid, reactive liquid, and aggregate, if present.
On this basis, although it is possible to make a marginally satisfactory grout from compositions containing 5-10 percent of a cement that sets by hydration, in order to provide maximum strength capability it is preferred that the amount of such cement constitute more than 10 percent of the total weight of the composition. Sufficient reactive liquid should be present to react with such cement, e.g., sufficient to give a water/cement weight ratio of at least about 0.1, and preferably at least about 0.3. In order to be able to allow for the incorporation of a sufficient amount of aggre-gate and reactive li~uid into this system, the amount of cement will not exceed about 80 percent of the total weight of the two components; and a maximum cem~nt content of about 50 percent is preferred inasmuch as no advantage in terms of final strength is seen in exceeding this amount.
The specific amounts of liquids used in the composition will depend on the amount of solids present, ease of delivery, mixing, etc. From strength considerations, it is undesirable to exceed significantly the stoichiometric amount of reactive liquid and the amount of slush-forming liquid required to give the necessary lubricity and deliverability (e.g., pumpability). A liquids/solids weight ratio of the combined components in the range of about from 0.1 to 0.6 is satisfactory from the viewpoint of strength, and handling and mixing con-siderations. In accordance with these considerations, the water/cement weight ratio in cement systems that set by hydration generally will not exceed about 1.0, preferably 0.7; and the amount of water, based on the total weight of the two components, will be about from 2 to 50, and preferably 5 to 30, percent. Also, the amount of slush forming liquid will vary about from 5 to 50, preferably 8 to 20, percent of the total weight of the composition; or about from 10 to 75 percent, preferably 35 to 65 percent, of the weight of the cement.
The reactive liquid in the second compo-nent of the grouting composition, and the acidic component of a basic/acidic phosphate system contain-ing aqueous phosphoric acid, preferably are in thickened form, e.g., contain a thickening agent.
This reduces the chance that the liquid will run out of an upward-slanting hole or soak into fissures or pores in the hole wall. The thickening agent is a solid material that absorbs water, is hydratable, or is somewhat water-soluble, and can be an inorganic material such as clay or fumed silica, or an organic material. Organic thickening a~ents that can be used include carbo~ymethylcelluloses, polyvinyl alcohols, starches, carbo~y vinyl polymers, and other mucilages and resins such as galactomannans (e.s., guar sum), polyacrylamides, and polyethylene oxides. Poly-ethylene oxide, polyacrylamide, and mixtures of the two are preferred. These two materials not only provide the thickening effect needed to reduce the chance that the water will run out of an upward-slanting hole or soak into fissures or pores in the hole wall, but are lubricants as well, in the sense that they facilitate the insertion of a bolt into an aggregate-water slush, the aggregate having less tendency to settle or pack in water containing these materials. Moreover, the beneficial effect of these thickener/lubricants is achieved with sufficiently small amounts thereof that grout shear strength is not severely compromised. In phosphoric acid systems because of their stability therein polyethylene oxides are preferred organic thickeners.
The amount of thickening agent in the reactive liquid component, e.g., the acidic reactive component, depends on the specific material used, and specifically on the degree of thickening of the liquid component attainable therewith, a function generally of the molecular weight and degree of substitution of the material, and depends also on other solid materials which may be incorporated in the reactive liquid component. Generally, the amount of thickening agent will be in the range of about from 0.1 to 1, preferably to 0.5, percent of the total weight of the composition, the lower end of the range being used with materials of higher mole-cular welght and/or having more hydrophilic groups.

ll~Z556 In the case of the organic polymers, more thanabout 0.2 percent, based on the total weight of the composition, usually will not be necessary.
One or more surface-active agents can be incorporated into the reaction system, in either one or both of the components. A surface-active agent in the cement slush or in the reactive liquid component containing suspended sand particles produces the consistency of a smooth paste, which results in improved ease of mixing of the components.
The surface-active agent should be soluble in the liquid of the component in which it is used, and should give a hydrophilic-lipophilic balance value of about from 8 to 14, as determined according to the methods outlined in "The Atlas HLB System", Atlas Chemical Industries, Inc., 1952. About from 0.1 to 10, and preferably from 1 to 5, percent of surface-active agent is used. However, since the presence of a surface-active agent can result in a hardened grout of lower shear strength, it is necessary to assess what effect, if any, the surfactant under consideration has on strength, and to balance this finding against the advantage to be gained in ease of mixing. Surfactants which can be used include oleic acid, sorbitan monooleate and monolaurate, polyoxyethylene monooleate and hexaoleate, poly-oxyethylene sorbitan trioleate and monolaurate, and polyoxyethylene tridecyl ether. Of these, oleic acid is preferred both on the basis of degree of effectiveness and cost.
The present grouting system can be used wherever structure reinforcement is required, e.g., in rock bolting or roof bolting in _oal or metal mines, or to secure bolts in holes drilled in concrete structures. If the components of the system ll~Z556 are delivered into the drill hole by pumping, they preferably are pumped into the hole separately and combined and mixed therein before or after bolt insertion, Alternatively, pumped components can be combined just outside the hole and mixed there or in the hole. Preferably the components of the grouting composition are delivered into the drill hole, and the reinforcing member is introduced into the composition before any substantial hardening of the composition has occurred, whereby grouting com-position is forced into an annulus formed between the reinforcing member and the wall of the hole.
The components are thereafter mixed, preferably by the rotation of the reinforcing member, to form the hardened grout. A preferred system comprises a frangible compartmented package having at least two components in separate compartments, the package being broken by penetration by the reinforcing mem-ber. One such package is shown in FIG. 1. In FIG.
1, a tubular member 1 of substantially circular transverse cross-section and a diaphragm 2 are constructed by wrapping a single web of pliable film material in a manner such as to form a con-voluted tube having a partially single-ply and partially double-ply wall, the inner ply of the double-ply wall portion forming diaphragm 2. The two plies of the double-ply portion are sealed together near inner edge 3 and outer edge 4 of the web so as to form linear junctures or seals 5 and 6, respectively. Tubular member 1, diaphragm 2, and junctures 5 and 6 define two separate compart-ments 7 and 8. At each end of the compartmented tubular member, one of which is shown in FIG. 1, the end portions of tubular member 1 and of diaphragm 2 are collectively gathered together and closed Dy 11~2556 closure means 9. Compartment 8 is filled with Component A described in Example 1 which follows, and compartment 7 with Component B described in the same example.
In use, this package is inserted into a drill hole, and a bolt is forced into the package, tearing the film and penetrating a part, or the full length, of the package. The components are mixed by rotation of the bolt, and subsequently react with hardening so as to secure the bolt in the hole.
The invention will now be illustrated by way of the following examples. Parts are by weight.
Example 1 A two-component reaction system of the following composition was made:
Component A Component B
19.05% cement 0.12% polyacrylamide 28.S7~ sand 28.57% sand 11.43% oil 12.26~ water The percentages are percent of the ingredients by weight, based on the total combined weight of the two components. The cement was "Very High Early Strength" (VHE) cement, manufactured by U.S. Cypsum Co., a fast-setting cement that sets by hydration, described in U.S. Patent 3,860,433. This cement contains (by weight) about 20-40% 3CaO 3A12O3-CaSO4 and about 10-35~ chemically unbound CaSO4, the remainder being substantially ~-2CaO-SiO2. The sand was Ottawa Silica Company's Banding Sand. This sand has round particles, 94~ of which are in the size range of 74 to 210 microns. The median particle size is 142 microns, and the deviation +
48g. The sand has 99% of its particles smaller than 420 microns. The surface area of the sand is about 160 cm2~g. The polyacrylamide was "Polyhail"* 295, made by the Stein Hall Company. The oil was kerosene.
The slush of cement, sand, and oil was kept separated from tne thickened water/sand combination. For strength testing, the two components were mixed to substantial homogeneity, whereupon oil was exuded therefrom, and the resulting ~aste-like composition hardened.
The shear strength of the grout, measured after 24 hours, was 336 kg/sq. cm. The method of measure.~ent was the following:
A sample of the freshly mixed grout was placed on polyethylene terephthalate film, and a stainless steel rins, 15.9 mm in diameter and 2.92 mm high, was placed on the grout. ~ piece of poly-ethylene terephthalate film was placed over the ring, and the latter then was pressed evenly into the grout by means of a block of wood. The resulting '~shear button" of the grout was placed on an InstrGn testing machine (conforming to ASTM Method E4, Verification of Testing Machines), and tested (24 hours after mixing) for shear strength by the method of AsTr~
D732 (ASTM is the American Society for Testing and Materials). In this test, a plunger was brought down onto the grout at a rate of 12.7 mm per minute.
The shear strength was calculated from the applied force to cause failure, according to the following equation:
shear strength = Force Specimen thickness ~ ~J x diam. of punch The grout also was evaluated after 24 hours in terms of its average pull strength, i.e., 450 kg~cm, accordins to the following procedure:
Freshly mixed grout was placed in a section * denotes trade mark of 2.54-cm threaded pipe, and a standard 1.59-cm-diameter steel blunt reinforcing rod was inserted into the grout. The excess grout which was squeezed out during insertion of the rod was scraped off, and

5 the pipe-rod assembly was placed into a test fixture mounted in an Instron Universal Testing Machine. The rod was then pulled (24 hours after the mixing of the grout) by applying a measured upward force to the bolt while the pipe section of the pipe-rod assembly was held stationary in the fixture. The force at which the first discontinuity in the recorded force vs.
deflection curve was observed was the pull strength.
Example 2 Four dual-compartment frangible packages in the form of 46-cm-long, 2.3-cm-diameter "chub"
cartridges as described in U.S. Patents 3,795,081 and 3,861,522 and as is shown in FIG. 1 herein, and containing a two-component reaction system of the invention, were made from a web of polyethylene terepnthalate film. One compartment contained a slush of the cement, sand, and oil described in Example 1.
The other compartment contained water and the sand and thickener described in Example 1. The ingredients content based on the total combined weight of the 5 contents of the two compartments was as follows:
Cartridges Cartridges a and b c and d cement 34% 32~
oil 13% 13%
sand 31.4%* 30.2%**
water 21.6% 24.8 thickener 0.10~ 0.10 *26% in the cement slush; 5.4% in the water **24% in the cement slush; 6.2~ in the water 5 Each sealed cartridge was placed in a 2.54-cm-diameter ll'iZ556 steel pipe having a rough wall and a welded closure at one end (simulated drill hole). ~he pipe was held in an upright position in a vise with the closed end uppermost. ~ headed reinforcing rod ~bolt) 15.9 mm in diameter was inserted into the cartridge with a rotating upward motion, and spun at 3G0 rpm to mix the contents of the package. A washer closed off the bottom end of the pipe. Ambient temperature was 27~C.
After one hour the pull strength of the grout was determined by applying force to the headed end of the bolt in a downward direction at a rate of 1.27 cm per minute. The results are shown in the following table:
Mixing Force Time Required To Cartridge (sec) Cause Slippaqe 1 5 _ _ a 7.5 10.2 x lCJ kg b 20 12 x 1~3 kg c 7.5 9.1 x 103 kg d 17.5 9.2 x 103 kg Example 3 A cement-oil slush and an aqueous sand mixture in the proportions 28.57% cement, 14.29~ oil, 42.86~ sand, and 14.29~ water (same cement, oil, and sand as described in Example 1) were mixed thoroughly, and shear buttons prepared from the freshly mixed grout as described in Example 1. The buttons were tested for shear strength after seven different periods of time, according to the procedure described in Example 1. The results are shown in FIG. 2, where shear strength is plotted vs. time on a logarithmic scale. It is seen that this grout achieved a shear strength of 70-140 kg/sq cm (equivalent to the strength of coal mine roof strata) in 30 to 90 minutes, and well over 90 percent of its full strength (equivalent to the strength of metal mine roofs) in less than 4 hours.

Example 4 ~1) The following separate com~onents ~ere ?repared:
Component A (parts) Component B (parts) cement (26.32) sand (19.74) sand (19.74~ 1~ aqueous solution of oil (14.47) polyacrylamide (19.74) The sand and oil were the same as those used in Example 1. Five different mixes of Com?onent A were prepared, each with a different cement. The 24-hour shear strength of the grout prepared by mixing each one of the five A Components with Component B was measured as described in Example 1. The results were as follows:
Cement in Component A Shear Strength (kg/sq cm) -Ordinary Portland (Type II)~ 5 I'Rapid Rock"*(a) ~ 4 Huron Regu~ated Set Portland Cement (RSPC) (b) 0 Hydrostone* Super X(C) 42 (a) Reported as producing a fast-setting (15 min) pourable grout when mixed with water, setting to 350 kg/sq cm in one hr (Tamms Industries Co.
TI-103, 1974) (b~ Type III, contains calcium aluminum fluorite, reported to be fast-setting and able to gain strength at a rapid rate during the earlv ages of the concrete (National Gypsum Co., Huron Cement Div. data sheets) (c) Calcined gypsum, U.S. Gypsum Co.
(2) Strength/setting time characteristics of cements used in Part (1) in the absence of oil.
Each of the cements (20 parts) listed in * denotes trade mark Part (1) above was ~ixed with 30 parts of the sand, and an amount of water was added according to the manufacturer's specifications to achieve maximum strength at minimum age. The nu~ber of minutes 5 required for each oil-free grout to become hard is given in the following table:
Cement Hardening Time VHE ~ 20 min Ordinary Portland~ 24 hrs "Rapid Rock" ~10 min Huron RSPC ~20 min Hydrostone Super X~20 min The following table gives the compressive strengths (manufacturer's specifications) and 24-hour shear strengths ~measured as described in Example 1) for oil-free grouts made from the cements listed in Part (1) above. The shear test specimens were pre-pared from grouts made by mixing 10 parts of the cement with 15 parts of sand and 3.5-4.5 parts of 0 water (according to manufacturer's specifications).
Compressive Strength Shear kg/sq cm (time inStrength Cement hrs)_ kg/sq cm VHE ~ 350 (24) 375 Ordinary Portland ~140 (24) 84 "Rapid Rock" 350 (1) 251 Huron RSPC ~ 210 (24) 452 Hydrostone Super X ~455 (1) (wet) 265 ~945 (l)(dry) Example 5 The effect of sand content on the 24-hour shear strength of the grout was examined with a system wherein 28.6 parts of the cement described in Example 1 and 14.3 parts of-the oil described in Example 1 formed one component, and 14.3 parts of a il'~Z556 ,. ., 1 percent aqueous polyacrylamide solution formed the other component, and an amount of sand was divided evenly between the two components. The results are shown in the following table:
Sand Shear Strength Parts~ % (kg/sq cm)*

14.9 242 46.8 737 *Measured as described in Example 1.
Example 6 A reaction system in which 18.7 percent cement and 13.1 percent oil (same cement and oil as in Example 1) were in Component A, 12.1 percent of a 1 percent aqueous solution of polyacrylamide was in Component B, and 56.1 percent sand (the sand used in Example 1) was located as indicated in the follow-ing table, was tested for shear strength as described 20previously:
24-hr Shear Strength kg/sq cm 100% in Component A 327 100% in Component B 288 ~50% in Component A~
25~50% in Component BJ 292 These results show that the distribution of sand between the components has no significant effect on the shear strength of the hardened grout inasmuch as all of the values are within + 10 percent of the average value, a deviation possibly due to experi-mental error in the test procedure.
Example 7 Fibrous materials were added to the cement-oil slurry in the following experiments.
3 (a) A grout made by mixing a cement-oil slush containing 28.19 parts V~E cement, 14.25 parts of the oil described in Example 1, and 0.28 part of 1.27-2.54-cm-long glasswool fibers with an aqueous sand suspension containing 42.74 parts of the sand described in Example 1, 14.25 parts of water, and 0.14 part of poiyacrylamide, had a l-day shear strength (method of Example 1) of 291 kg/sq cm. The same slurry without the glasswool gave a grout having a l-day shear strength of 235 kg/sq cm.
(b) The 4-hour shear strengtn of a grout made by mixing 40.61 parts ~E cement and 18.27 oil (same as that of ~.xample 1) with 20.30 parts sand (same as that of Example 1) and 20.30 parts of a 1 percent aqueous solution of polyacrylamide was increased from 98 kg/sq cm to 123 Xg/sq cm by the addition of 0.51 percent of 1.27-cm-long Kevlar~
(ara~lde) fibers to the cement slush.
Example 8 Different organic liquids were tested as slush-forming liquids by combining 20 parts of VHE
cement with 10 parts of the liquid being tested, adding 10 parts of water to the resulting slush, mixing the cement and water components, and testing the resulting grout qualitatively for hardness.
The results were as follows:
Slush-Forming Agent Grout Characteristics pentane hard in ~7 min hexane hard in ~7 min heptane hard in ~7 min benzene hard in ~5 min toluene hard in ~-10 min xylene hard in ~J7 min gasoline hard in ~ 8 min fuel oil ~2 hard in ~ 9 min il'~ZSS6 ~2 Slush-Forming Agent Grout Characteristics kerosene hard ~n ~ 6 min Nujoi hard in ~ 23 min methanol hard in _ 7 hr When the above-described procedure was rollowed wit;~out the addition of a slush-~orming liquid, the grout became hard in 5 minu.es.
Example 9 One of the benefits achieved by employing the cement in the form of a slush was studied bv comparing ,he force required to insert a bolt into the slush as contrasted to that needed to penetrate a dry cement. ~ 2.54 cm-inne--d ameter steel ?i?e was filled with the cement component, and a 15.9-mm-diameter steel reinforcing rod was moved downward into the component in an Instron* machine at a rate of 51 cm per minute. A force of only about 0.2 kg was required to penetrate 2.5 cm of a slush con-sisting of 44.44 percent cement, 33.33 percent sand, and 22.22 percent ~apoleum* 470 (a predominately aliphatic kerosene) or Circosol* 410 (a naphthenic based oil made by the Sun Oil Company).
In contrast, a rorce of 1600 kg (maximum available on the Instron machine) was required to insert the bolt about 2.54 cm deep into a mixture of 57.1 parts dr~ cement and 42.9 parts sand.
Example 10 The following separate components were prepared:
Component A (parts) Component B (parts) cement (28.57) sand (42.86) oil (14.29) water (14.29) The cement and oil were the same as those used in Example 1. Three different mixes of Component B
were prepared, each with a different sand. The 24-* denotes trade mark hour shear strength of the grout prepared by mixing each one of the three B components with Component A
was measured as described in Example 1. The results were as follows:
Sand In Sand Shear Strength Component B Characteristics (kg/sq cm) Banding Sand See Example 1 246 "Sakrete"t Sand 95g 147-420j~; median (-35 mesh)* 288JU; deviation + 45~
100% ~540 ~. Jagged. 235 Sawing Sand 95% 297-420 ~; median (Otttawa-Silica 358~u; deviation +
Co.) 17~. 96% ~540 ~.
Round 117 *All-purpose "Sakrete" sand packaged by H. T. Camp~ell Company, Towson, Maryland Example 11 The procedure described in Example 10 was repeated with seven different graded sands in Component B. In this case, the cement content was 18.5 parts, oil 14.8 parts, sand 55.6 parts, and water 11.1 parts. All of the sands had round particles and were products of the Ottawa Silica Company, Ottawa, Illinois, and described in Ottawa's Product Data Sheet OD 3-74-0. The results were as follows:

t denotes trade mark ~4 PARTICLE ~I7E '~) SHEAR STRE~G~
a.~D ~GE.~E3~A~ DEVI~TION ~.~. KG~SQ C.
~1) ape~ial Bond 96~ 105-297 201 48~ 100~ ~'340 223 (~! 90nd S~nd ~7~ 105-297 '01 ~8~ 100~ <5~0 255 in~ àp~c~ 6~ 2~ 280 5~ 0~ <5~0 250 Bl~nd (d) ;0-~esh91~ 105-210 157 33~ 99~ <420 22 ie) 3andi~9 Sand 9~ 74-210 1~2 ~8~ 99~ ~20 22~
tf) 9~ aholl 96~ 74-210 112 ~8~ ~99~ <~20 231 (~) F-1~0 98~ <53-.~7 ~`100 ~7~ ~99~ <297 171 Example 12 The procedure described in Example 10 was repeated twice, once with a graded sand, i.e., the -35 mesh "Sakrete" described in Example 10, and once with a uniform sand, i.e., the 297-420 micron cut from the -35 mesh "Sakrete". The median particle size of the uniform sand was 358 microns, and the deviation + 17%. The 24-hour shear strength of the grout containing the graded sand was 472 kg/sq cm, and that of the grout containing the uniform sand 354 kg/sq cm.
Example 13 Two different sands were tested with respect to their settling rates in thickened water, as an indication of their behavior in stored two-compartment cartridges having a cement slush in one compartment and a sand/water mixture in the other. Segregation of the sand results in an asymmetrical package, which is harder and stiffer in one section than in another, making bolt insertion more difficult.
Both sands were "Sakrete". One was a coarse sand consisting solely of particles larger than 500 microns (53~ larger than 833 microns, 12%
larger than 2.36 mm, the remainder between 540 and 833 microns). The other was a fine sand consisting of the -35 mesh "Sakrete" described in Example 10.
Tubes 31 cm long and having a 2.5-cm-diameter were filled with a 1~ aqueous solution of polyacrylamide, and the sand was added to the tubes. The settling rate at 20C was about 20 minutes for about 90%
of the coarse sand, and about 46 minutes for about 90% of the fine sand.
Example 14 The following separate components were prepared:
Component A (parts) Component B (parts) cement (27.8) sand (41.6) oil (13.9) 1% aqueous thickener solution (16.7) The cement, oil and sand were the same as those used in Example 1. Different mixes of Component B were prepared, each with a different thickener. The 24-hour shear strength of the grout prepared by mixing each of the A Components with Component B
was measured as described in Example 1. The results were as follows:
Thickener Chemical Shear Strengtb Type Cs~n~nercial Desiqnation !kq/sq cm) Polyacrylamide Polyhall 295 (Stein Eall) 139 Polyacrylamide E~olyhall M40 (Stein Hall) 164 rolyacrylamide Polyh~ll 650 (Stein 8all) 113 Polyetbyler.e oxide Polyox~ 301 (Union Carbide) 81 Sodium carboxymethylcellulose Sodium CMC lDu Pont) 148 SGc~ium carbo~:ymethylcelluloseSodium CMC (}~ercules) 182 Methylccllulose derivative Methocel~ HD IDow) 16 Methylcellulose cerivative Methocel J5MS (Dow) 50 ~lethylcellulose derivative Methocel J75YS (Dow) 27 ~lethylccllulos~: derivative Methocel E41~ (Dow) 38 Methylcallulose derivative Met~,ocel 1;4M (Dow) 20 ~ethyic211ulose derivative Methocel XlSM (Dow) 17 Natural gum Jaguar~ 180 (Stein Hall) 163 ~atural gum Jaguar 180 (Stein Hall~67 When the above-described procedure was repeated with no thickener, the shear strength was 333 psi.
Example 15 A 2.54-cm inner diameter steel pipe was filled with a mixture of 75% sand (-35 mesh "Sakrete" made by H. T. Campbell Company, Towson, * denotes trade mark il4Z556 Maryland) ~nd 25~ of a 1% aqueous solution of a thickener, and a 15.9-mm diameter steel reinforcing rod was moved downward into the mixture in an Instron machine at a rate of 51 cm per minute. The force required to insert the rod 2.54 cm was measured.
The results were as ollows:
Force Needed For 2.54 cm Thickener Penetration (kg) Polyox 301 5 10 Methocel HD 22 Polyhall 295 57 Jaguar 180 91 Sodium CMC 94 Hercules CMC 149 A force of 608 kg was required when no thickener was present, and 588 kg when no water or thickener was present.
Examples 14 and 15 show that, of the thickeners which permit a shear strength of 70-140 kg/sq cm to be retained, polyethylene oxide and polyacrylamide are superior in ease of bolt pene-tration, and thus are particularly suited for use in cement grouts for anchoring rock bolts.
Example 16 When the procedure described in Example 15 was repeated with the use of the sand described in Example 1 (Banding sand), a force of only 0.2 kg per 2.54 cm of insertion was required for the Polyhall 295 and the Polyox 301 solutions.
Examples 17-21 A surfactant (0.2 part) was added to a grout of the following composition:

`" li ~5~6 Component A Component B
VHE cement (19.76 parts) sand * (29.64 parts) sand * (29.64 parts) 1% aqueous solution of oil * (7.90 parts) polyacrylamide 112.85 parts) * Same as in Example 1 The grouts obtained upon mixing of Components A and B were tested after 24 hours for shear strength as described in Example 1. In all cases in which a surfactant was employed, the component containing the surfactant was a smooth paste, and mixing was easy.
Component 24-hour S~ear Example ~LB Contg.Stren~t~

No. Sur~-ctant Chemic~l Compound Value~ Surfac~ant kg~sc cm 15 17 none 2 5 18 Tween~ 81 Polyo~ethylene monooliatc 10 ~ 133 19 T~ecn 85 Polvox~cthylene sDrbit~n trioleale 11 ~ 72 2020 Sp~mt 20 Sorbit~n n~onol~ te 8.6 A 39 21 G1086 Polyoxyethylene hexaole~te 10.2 A 5_ - evdrophilic-Lipophili~ Balance ~ Component ~ was 19.01 part~ cement 2&.S2 p~rt~ ~nd ~nd ~1.31 part~ oil Component B w~s 28.i2 part2i s~md and 12.36 partC polyacrylam~de ~olution ~xample 22 The following components were prepared Component A Component B
VHE cement (31.16 parts) sand * (46.74 parts) oil * (6.23 parts) 1% aqueous solution Span 80 ** (0.12 part) polyacrylamide Tween 85 (0.16 part ) (15.58 parts) * Same as in ~xample 1 ** Sorbitan Monooleate Component A (113 parts) and Component B (187 parts) were packed into the separate compartments of the polyethylene terephthalate film cartridqe described in Example 2. The cartridged grout was subjected to a pull strength test in a simulated drill hole as described in Example 2. Twenty-four hours after t denotes trade mark " ll~Z5S6 the components had been mixed, the pull strength of the hardened grout was 11 x 103 kg.
Example 23 The following two components were made:
Component A Component B
Hydrostone* (2000 parts) Water (1758 parts) ~arcol 90 N.F. (369 parts) .~ethocel 65 (35 parts) Light Mineral HG (Dow) Oil (Exxon) Stearic acid (22 parts) Sodium stearate (114 parts) *a commercial cement consisting essentially of calcined gypsum Component A was made by heating a mixture of the oil and stearic acid to 57C to dissolve the stearic acid, and mixing the resulting solution with the hydrostone in a turbine mixer. Component B was made by heating a mixture of the ingredients to 57C
to dissolve the sodium stearate and produce a thick paste. When Components A and B were mixed in the weight ratio of 6.38/1 A/B, the mixture set up into a solid within a few minutes.
One compartment of a 61-cm-long dual-compartment cartridge described in Example 2 was filled with Component A and the other compartment with Component B in the weight ratio of 6.38 parts of Component A for every part of Component B. The filled cartridge was stored for 10 days and then tested for rock bolt anchoring substantially as described in Example 2. A 76-cm-long rock bolt was inserted into the cartridge at a rate of somewhat less than 1.2 meters per 15 seconds, while the bolt was spun at 450 rpm. The bolt was spun for 5 or 10 seconds after insertion.
When the grouted bolt was pull-tested after 12.5 minutes, no slippage occurred until a force of 8200 kg had been applied.

" ll~Z556 Example 24 ~ grouting composition was prepared which had the following components:
Acidic and Aqueous Basic Component Components 13.2% MgO 18.5~ aqueous Al(H2PO4)3 solution 35.9% Sand 21% Sand 11.4% Circosol 304*
(containing 2.5% oleic acid surfactant) *A napthenic Petroleum oil manufactured by the Sun Oil Company The percentages are percent of the ingredients by weight, based on the total combined weight of the components, The magnesium oxide had a surface area of 5.7 square meters per gram. The sand was Ottawa Silica Company's Banding Sand. This sand has round particles, 94~ of which are in the size range of 74 to 210 microns, and 99% of which are smaller than 420 microns.
The composition of the aluminum phos?hate solution, by weight, was 11.5~ A12O3, 47.7~ P2O5, an 40.8% H2O.
The basic component (234 ?arts) was intro-duced into one compartment, and the acidic andaqueous components (151 parts) into the other compart-ment, of a two-compartment frangible "chub" cartridge such as that described in U.S. Patents 3,795,081 and 3,861,522, the cartridge being made of polyethylene terephthalate film. In the sealed compartmented cartridge, which was 41 centimeters long and 2.3 centimeters in diameter, the basic com?onent and acidic/aqueous component were maintained se?arate from one another. The cartridge was cooled to 10C
(to simulate the average temperature in a mine) and " ~14ZSS6 placed in a 41-cm-long, 2.54 cm-inner-diameter steel pipe having a rough wall (coarse threads) and a welded closure at one end (simulated drill hole).
The pipe was held in an upright position in the vise of a Mayo* machine with the closed end uppermost.
The Mayo machine is one which is commonly used in mines to drill holes into mine ceilings and to install roof bolts for grouting. A 61-cm-long reinforcing rod (bolt) having a diameter of 2 cm also was mounted in the Mayo machine. Both the pipe (drill hole) and the bolt were at 10C.
Upon actuation of the machine, the rod was inserted into the cartridge with an upward motion at a speed of 6 meters per minute at 400 rpm. During insertion the bolt broke the polyethylene terephthalate film. After the bolt reached the closed end of the pipe, the bolt was spun for 35 seconds and completed mixing of the initially separated components.
Five minutes after the bolt installation had been completed, the pull strength of the hardened grout was measured by applying an increasing force to the headed end of the bolt in a downward direction.
The bolt broke at a load of 15.5 x 103 kg. Therefore, the grout supported a load of more than 378 kg per centimeter of anchoring length and exceeded the steel bolt in strength.
Example 25 The procedure described in Example 24 was repeated except that the magnesium oxide content of the grouting composition was 17~, sand 31.5~ in basic, 15.3% in acidic, component, Circosol 12.7%
and aluminum phosphate solution 23.6% and the magnesium oxide surface area was 10 square meters per gram. The chub cartridge was 51 cm long, and * denotes trade mark contained 201 parts of the basic component and 128.5 parts cf the acidic/aqueous component. In this case, after five minutes, the bolt broke at a load of 21.8 x 103 kg, the yrou. havin~ su?ported a load of more than ~27 kg per centimeter of anchorinq length.
ExamPle 26 A grouting composition was prep2red which had the following components:
Acid and Aqueous Basic Component Components -MgO (43.62 parts) 74% aqueous solution of H3PO4 (32.8 p2rts) A12O3-3H2O (23.44 parts) Sand (67.12 parts) Circosol 304 (32.12 parts) Polyethylene oxide (0.08 part) Oleic Acid (0.82 part) The surface area of the magnesium oxide was 10 m2/9.
The sand was the same as that described in Example 24.
The polyethylene oxide, which served as a thickener for phosphoric acid, was Polyox 301, having a molecular weight of about 4,000,000.
The composition was loaded into a cartridqe and tested as described in Example 24. The two-component cartridge contained 82.5 parts of the basic component and 199.5 parts of the acidic/3queous component. The bolt was inserted into the cartri~ge at a speed of 3 meters per minute and a thrust of 454 kg. and mixed at a torque of 68 Newton meters.
The total time required for bolt insertion and mixing was 25-27 seconds. In the 5-minute pull test, the bolt broke at a load of 15.2 x 103 kg, the grou.
having supported a loa2 of more than 372 kg per centimeter of anchoring length.
Example 27 The effect of the surface area o~ magneslum oxide ?articles on the rate of hardening of a given grouting composition is shown in a series of experiments made with a composition containing 13 ~IgO, 7% .~12O3 3I~2O, 10~ Ci.cosol 304, 23~ H3PO4 ~74~ aqueous solution), and 47~ sand, the basic component cor.taining the MgO, A12O3-3H2O, oil, and sand in an amount which was 20~ of the total welgh~
of the composition; and the acidic/aqueous com?onent containing the H3PO4 solutlon and the remainder of the sand. The composition was tested for 5-minute pull strength as described in Example 24.
MgO Surface Area Pull Strength 2/g) (kg/cm) 1.1 0 2.6 129 4.4 243 5.6 393

6.5 643 Thus, at the 13~ MgO concentration level, grouts having MgO surface areas below 4.4 m2~g requ red longer than 5 min~tes to attain strength levels o 175 kg/cm. Above 10 m2/g, the setting rates her_ ~a hign adequate mixing of the com?onents could not be accomplished.
Example 28 The following experiments show that a com-position having a small surface area MgO and low setting rate can have its setting rate increased increasing the MgO concentration. The experimen~s were carried out on the composition described in Example 24 except that the MgO content was varied, the difference in the MgO content f~om that in Example ~4 having been reflected in a prOpQrtionate decrease or increase in the sand content of the basic component described in Example 24.

11~2S56 5-Min Pull Stre.-gth .~q~ (ka~cm) 11.6 321 i~ 536 1~ ,86 When the comDosition described in Exam?le 24 was made with MgO having a surface area of 1.1 m2/g, the 5-minute pull strength was 0 kg~cm, but at a MgO level of 25~, the composl.ion nac a 5-minute pull strenqth of 786 Xg/cm.
Exampl_ 29 A grouting composition was prepared which had the following components:
Acidic and Aqueous Basic Component Components 18.0% MgO 18~ aqueous Al(H2PO4)3 solution 35.6% Sand 20~ Sand 8.4~ Circosol*
*A mixture of 48.7~ Circosol 450, 48.75% Circosol 4240, and 2.5~ oleic acid.
The MgO was of the dead-burned type, having a surface area of 0.8 m2/g, and a median particle size of 6 microns.
When cartridged and tested according to the procedure described in Example 24 (30 second mix time after installation; bolt insertion at 1000 kq thrust and mixing at 163 Newton meters torque), the 5 minute pull strength was 317 kg/cm.
Example 30 The following groutinq compositions were prepared:

~ 3 Basic Com~onent Basic ComPonent ^~
13~ .~gO ~10 m2fg) 15.4~ `tgO (10 m~g) 10~ Oil containing 2.5% 23 3 2 oleic acid 27~ Sand 11.8~ Oil 23.7~ Sand A_idic/Aqueous Component Acidic/Aqueous Component q 3 4 ( 4%) q 3~4 ( 27% Sand 21.9% Sand Both compositions were tested as describe-in Example 24, except that the pipe and bolt lengths were 12.7 cm. Mixing time after the bolt was in place was 30 seconds. With Compositian A, the hardened grout, after five minutes, supported a load of up to 786 kg/cm and then failed. Composition B
supported more than 857 kg/cm.
Examples 31-34 The effect of the water content of tAe grouting composition (or the concentration of the Al(H2PO4)3 solution) is shown in a series of ex?eri-ments made with a composition containing 13% MgO, 10.4% Circosol, 57.9% sand, and 18.7% Al(H2PO4)3 solution of different concentrations.
Al(H2P4)3 soln- % Water in Strength _ ( 2PO4)3 ~ H20 Groutinq Compn. (kq/cm) 31 71.6 28.4 5.3 714 32 69.7 30.3 5.7 393 33 67.3 32.7 6.1 321 34 47.6 52.4 9.8 71 Examples 35-39 Five different compositions were prepared using an approximately 70% aaueous Al(H2POq)3 solu-tion (11.2~ A1203 and 46.8~ P20~) in the acid~aqueous component. In all cases, 61-cm-long, 2-cm-diameter bolts were installed into the grout as described in Example 24 and pull-tested 5-10 minutes after installation. Com?ositions, mole ratios, and pull strengths are tabulated below:
Ex. Ex. Ex. Ex. Ex.

% MgO 8.9 13.9 17.021 23 MgO Surface Area, m2/g 20 15 10 -1 ~i % Oil* - - 12.712.4 13.5 % Glycol** 7.9 11.4 - ~ ~
% Sand 56.0 56.7 46.849.1 53.6 (H2PO4)3 Soln. (70%) 27.2 18 23.617.5 10 Moles .~gO/P2O5 2.45 5.7 5.4 9.0 17.3 Pull Strength (kg/cm) 242 280 357 280 182 * Circosol containing 2.5~ oleic acid; in basic component **In basic component Exam~les 40-45 Grouting compositions wherein oil was not present as a slush-forming liquid for the basic .met21 compound were prepared and tested as described in Example 24. Details of the compositions and test results are given in the following table:

~cldic/Water _~. Basic 0Ompon~nc C.~mDon~nt 5-~in, Pull Test Slush- Oxy Formin~ Phosphorus `~e~al Compd.* Sand* Liquid* Compd.* Sand~ Condltions Result 41) 16.$X ?150 ~9.4~ ~q ~3-cm cartridoe 371 kgJaD
(-lSm2~g) none none ( 2 4)3 54.2X ~eighins 347.9 g;
soln. (a) 61 cm x 2 cm thrust, 300 rpm, 6 meters/

41 12.8X MgO 38.3X 8.5Z 23.4X aq. 17.0Z 13 cm x 2 cm 357 ks/cm (5.7 m2/g) water ( 2 4)3 bolt; mixed 1 0 soln. (b) 30 sec at 400 rpm 42 18.3Z2~gO 12% 18.8X aq. 18.2X mixed 15 sec at 256 kg/cm (15 m /g) 32.7Z glycoL Al(H2PO4)3 320 rpm soln, (c) 4311.9% Mg(OH)2 28.7X 9.5X 25.0~ aq. 25.0% 61 cm x 2 cm 259 kg/cm water Al(H2P04)3 bolt; 300 rpm, soln, (d) 7 meters/min 4414.0Z Hg(OH)2 28.0Z 7.7Z 23.77, aq. 24.4X mixed 15 sec 348 kg/cm glycol Al(H2PO4)3 in 10 ~in watler Soln, (d) 2 0 45 10.10Z ~go 30 30% 9 09Z 20.20X aq. 30.30X -- --water(8) Mg (H2P04) 2 soln. (f) *Z content i5 based on the total weight of the composltion 2 3 ' 2 5 X, H20 0.8Z
(b) A12O3 11.5%, P205 46%, H20 4 2. 5X
2 5 ( ) 2 3 ' 2 5 5 ~ 2 3 5%
(d)AlzO3 11.2Z, P205 45.6Z, H20 43.2~
(e)A1203 11%, P205 47X, H2O 34X, glycol 8X
(f) 42 9 g MgO. 401.0 g H3PO4 (85X), 556.1 g H2O per kg. soln, (g) Thickened wlth lX polyacrylamide In Example 45 the grout was evaluated by a shear strength measurement made ~y the following method:
A sample of the freshly mixed grout was placed on polyethylene terephthalate film, and a stainless steel ring, 15.9 mm in diameter and 2.92 mm ~ Z556 high, WdS placed on the grout. A ?lece o~ ?oly-eth~-lene tere?hthalate film was placed over the rins, and the lat~er then was ~ressed evenly into the grout b~- means of a block of wood. The resulting "shear bu~on" of the grout was placed or. an Instron testinc machine (conforming to ASTM Method _4, Verification of Testing Machines), and tested (5 minutes a~ter mixins) for shear strength by t.he method of ASTM D732. In this test, a plunger was brought down onto the grout at a rate of 12.7 mm ?er minute. The shear strength was calculated from the applied force to cause failure, according to the following equation:
shear strength = Force k apeclmen thlc ness x ~x dlam.
punch The measured shear strength was 9Q kg/
sq cm.
Example 46 A grouting composition was pre?ared containing 9.0~ magnesium oxide (10 m2/g), 14.1~
Circosol 450, 52.2~ banding sand, 11.8~ A1 (H2P04) 3 and 12.9% water. The MgO/P2O5 molar ratio was 4.
When tested as described in Example 30, the hardened grout held a load of 572 kg/cm.
Control Experiments _ _ In contrast, a composition containing 8.,~, magnesium oxide (10 m2/g), 14.7% Circosol 450, 50.6 banding sand, 13-0% NH4H2PO4, and 13.0~ water (MgO/P2O5 molar ratio= 4.4) held onl~ 45 kg/cm.
When a bolt was embedded into a mixture of 8-7~ MgO, 65 3% sand, 13.0% ~H4H2DO4, and 13,0C H2O
and tested as described in Example 30, the bolt was dislodged with less than 5 kg. force after 10 minutes.
Exam~le 47 The following composition was ?repared:

`` ll~ZSS6 13~ McO (surface area 13.4 m2/g) 56.4~ banding sand 12.0~ ethylene glycol (in basic com?onent) 18.6~ Al(H2PO4)3 solution (10.5~ A12O3, 42% P2O5) T~is grout, tested as describea in Exam?le 30, had a pull strength of 672 kg/cm in 5 minutes.

Claims (45)

CLAIMS:

1. A method of anchoring a reinforcing member in a hole comprising (a) delivering into the hole, in controlled amounts, two components of a hardenable inorganic grouting composition having (1) as a first component, a slush of a particulate inorganic cement and a liquid which is nonreactive therewith, and (2) as a second component, a liquid which is reactive with the inorganic cement, the inorganic cement constituting more than 10 percent of the total weight of components (1) and (2); and (b) introducing a reinforcing member into the grouting composition in the hole before any substantial hardening of the composition has occurred, whereby grouting composition is forced into an annulus formed between the reinforcing member and the wall of the hole, components (1) and (2) being delivered into the hole in a separated or freshly combined condition and intimately mixed, whereby the mixed components react rapidly in the annulus to form a hardened grout of sufficient strength to firmly anchor the reinforcing member to the wall of the hole.

2. A method of Claim 1 wherein the com-ponents of the inorganic grouting composition are combined in the hole and mixed by the rotation of the reinforcing member.

3. A method of Claim 2 wherein the com-ponents of the inorganic grouting composition are delivered into the hole from separate feeding conduits.

4. A method of Claim 2 wherein the com-ponents of the inorganic grouting composition are delivered into the hole in a frangible package in which they are located in separate compartments, and the package is penetrated and broken by the reinforc-ing member.

5. A grouting system for use in a hole in combination with a reinforcing member to anchor the reinforcing member therein by the reaction of two mixed components of an inorganic composition around the reinforcing member to form a hardened grout, the grouting composition having, in controlled amounts, (a) as a first component, a slush comprising a particulate inorganic cement and a liquid which is nonreactive therewith, and (b) as a second component, separated from the first, a liquid which is reactive with the inor-ganic cement, the inorganic cement constituting more than 10 percent of the total weight of components (a) and (b), components (a) and (b) being (1) present in the hole, or outside the hole and adapted to be delivered thereto separately or in freshly combined condition; (2) adapted to be forced into an annulus formed between the reinforcing member and the wall of the hole by the introduction of the reinforcing member into components (a) and (b) in the hole before any substantial hardening reaction has occurred between them; and (3) adapted to be intimately mixed whereby the mixed components react rapidly to form a hardened grout of sufficient strength to firmly anchor the reinforcing member to the wall of the hole.

6. A grouting system of Claim 5 wherein a particulate aggregate is present in one or both of the components in an amount such as to constitute about from 20 to 80 percent of the total weight of the components.

7. A grouting system of Claim 6 wherein the particulate aggregate is graded sand having a deviation of the maximum and minimum particle sizes from the median particle size of a size cut which includes 90 percent or more of the particles of more than about ? 20 percent, and having no more than about 10 percent of its total volume consisting of particles larger than about 600 microns.

8. A grouting system of Claim 6 wherein the inorganic cement is a cement that sets by hydration, and the liquid reactive therewith is water.

9. A grouting system of Claim 8 wherein the water is thickened by the presence of a polymeric material therein.

10. A grouting system of Claim 9 wherein a particulate aggregate is present in the water com-ponent, and about from 0.01 to 5 percent of poly-ethylene oxide and/or polyacrylamide, based on the total weight of the two components, is present in the aggregate-containing water component as a thickener-lubricant.

11. A grouting system of Claim 8 wherein the liquid nonreactive with the inorganic cement is a hydrocarbon, and the aggregate is sand.

12. A grouting system of Claim 11 wherein the grouting composition contains up to about 80 percent cement, about from 2 to 50 percent water, about from 5 to 50 percent hydrocarbon, and about from 10 to 70 percent sand, based on the total weight of the two components of the composition, the water/cement weight ratio being about from 0.3 to 0.7, the cement/sand weight ratio being about from 0.25 to 1, and the weight ratio of hydrocarbon to cement being about from 0.1 to 0.75.

13. A grouting system of Claim 8 wherein the cement is calcined gypsum.

14. A grouting system of Claim 8 wherein the cement is Portland cement.

15. A grouting system of Claim 8 wherein the cement contains, by weight, about from 20 to 40 percent of 3CaO?3Al3O3?CaSO4 and about from 10 to 35 percent of chemically unbound CaSO4, the remainder being substantially .beta.-2CaO?SiO2.

16. A grouting system of Claim 5, 6 or 7 wherein the components are located in separate feeding conduits for delivery to the hole.

17. A grouting system of Claim 8, 9 or 10 wherein the components are located in separate feeding conduits for delivery to the hole.

18. A grouting system of Claim 11, 12 or 13 wherein the components are located in separate feeding conduits for delivery to the hole.

19. A grouting system of Claim 14 or 15 wherein the components are located in separate feeding conduits for delivery to the hole.

20. A grouting system of Claim 5, 6 or 7 wherein the components are located in separate compart-ments of a frangible package in position in the hole, the package being adapted to be penetrated and broken by the reinforcing member, and the components to be mixed in the hole by the rotation of the reinforcing member.

21. A grouting system of Claim 8, 9 or 10 wherein the components are located in separate compart-ments of a frangible package in position in the hole, the package being adapted to be penetrated and broken by the reinforcing member, and the components to be mixed in the hole by the rotation of the reinforcing member.

22. A grouting system of Claim 11, 12 or 13 wherein the components are located in separate compart-ments of a frangible package in position in the hole, the package being adapted to be penetrated and broken by the reinforcing member, and the components to be mixed in the hole by the rotation of the reinforcing member.

23. A grouting system of Claim 14 or 15 wherein the components are located in separate compart-ments of a frangible package in position in the hole, the package being adapted to be penetrated and broken by the reinforcing member, and the components to be mixed in the hole by the rotation of the reinforcing member.

24. A grouting system for use in a hole in combination with a reinforcing member wherein a hardened grout is formed around the reinforcing member in the hole by the reaction of the mixed components of a hardenable inorganic grouting composition, thereby anchoring the reinforcing member in the hole, characterized in that the grouting composition is inorganic and comprises (a) an acidic reactive component comprising at least one acidic oxy phosphorus compound selected from the group consisting of phosphoric acids, anhydrides of phosphoric acids, and salts of phosphoric acids with multivalent metal cations;
(b) a basic reactive component comprising at least one particulate basic metal compound of a Group II or Group III metal capable of reacting with the oxy phosphorus compound(s) in the presence of water to form a monolithic solid; and (c) an aqueous component;
the components being present in or outside a hole in a separated condition such that any substantial hardening reaction between the acidic and basic components is prevented, and when present outside the hole being adapted to be delivered into the hole separately or in a freshly combined condition; the basic metal compound(s) having a particle surface area of up to about 40 square meters per gram and constituting about from 5 to 35 percent of the total weight of the grouting composition, with the proviso that when the particles of the basic metal compound(s) have a surface area of less than 1 square meter per gram, more than about 95 percent of the particles pass through a 200 mesh screen; the ratio of the moles of the basic metal compound(s) to the moles of phosphorus pentoxide on which the oxy phosphorus compound(s) are based being in the range of about from 2/1 to 17/1; the amount of water present in the compo-sition constituting about from 3 to 20 percent of the total weight of the grouting composition; a particulate aggregate being present in the composition in an amount such as to constitute about from 30 to 70 percent of the total weight of the composition; and the components, when mixed, reacting without the application of heat thereto to form a hardened grout having a pull strength of at least about 175 kilograms per centimeter of anchoring length within an hour.

25. A grouting system of Claim 24 wherein the aqueous component and acidic reactive component are combined and maintained separate from the basic reactive component.

26. A grouting system of Claim 25 wherein the combination of aqueous and acidic reactive compo-nents is an aqueous solution of phosphoric acid or of an acid salt of phosphoric acid with a multivalent metal cation.

27. A grouting system of Claim 25 wherein the basic metal compound is selected from the group consisting of magnesium oxide, aluminum oxide, magnesium hydroxide, ferric hydroxide, aluminum hydroxide, magnesium silicate, magnesium aluminate, and calcium aluminate.

28. A grouting system of Claim 24 wherein the basic metal compound is in a substantially dry state.

29. A grouting system of Claim 24 wherein the basic reactive component is in the form of a slush with a liquid which is substantially nonreactive with the basic metal compound(s).

30. A grouting system of Claim 24 wherein the basic metal compound is magnesium oxide or hydroxide.

31. A grouting system of Claim 25 wherein the basic metal compound is magnesium oxide or hydroxide.

32. A grouting system of Claim 26 wherein the basic metal compound is magnesium oxide or hydroxide.

33. A grouting system of Claim 28 wherein the basic metal compound is magnesium oxide or hydroxide.

34. A grouting system of Claim 29 wherein the basic metal compound is magnesium oxide or hydroxide.

35. A grouting system of Claim 30 wherein the basic reactive component additionally contains aluminum oxide.

36. A grouting system of Claim 31 wherein the basic reactive component additionally contains aluminum oxide.

37 A grouting system of Claim 32 wherein the basic reactive component additionally contains aluminum oxide.

38. A grouting system of Claim 33 or 34 wherein the basic reactive component additionally contains aluminum oxide.

39. A grouting system of Claim 25 wherein the solution is a solution of an acidic aluminum phosphate.

40. A grouting system of Claim 35, 36 or 37 wherein the solution is supersaturated.

41. A grouting system of Claim 29 characterized in that the substantially nonreactive liquid is a hydrocarbon.

42. A grouting system of Claim 29 wherein the substantially nonreactive liquid is a polyol.

43. A grouting system of Claim 29 wherein the substantially nonreactive liquid is water.

44. A grouting system of Claim 25 wherein the combined aqueous and acidic reactive components are maintained in one compartment and the basic reactive component in another compartment of a compartmented frangible package.

45. A grouting system for use in a hole in combination with a reinforcing member wherein a hardened grout is formed around the reinforcing member in a hole by the reaction of the mixed components of a hardenable inorganic grouting composition, thereby anchoring the reinforcing member in the hole, wherein the grouting composition is inorganic and comprises an aqueous solution of phosphoric acid or of an acidic aluminum phosphate, magnesium oxide or hydroxide separated from the aqueous solution, and sand; the magnesium oxide or hydroxide having a particle surface area of up to about 30 square meters per gram and constituting about from 5 to 35 percent of the total weight of the grouting composition; the ratio of the moles of the magnesium oxide or hydroxide to the moles of phosphorus pentoxide on which the phosphoric acid or phosphate is based being in the range of about from 2/1 to 17/1; the amount of water present in the composition constituting about from 3 to 20 percent of the total weight of the grouting composition; the sand being present in the composition in an amount such as to constitute about from 30 to 70 percent of the total weight of the composition; and the magnesium oxide or hydroxide and phosphoric acid or phosphate, when mixed, reacting without the application of heat thereto to form a hardened grout having a pull strength of at least about 175 kilograms per centimeter of anchoring length within ten minutes.