CA2185676A1 - Road surfacing composition and process - Google Patents
Road surfacing composition and processInfo
- Publication number
- CA2185676A1 CA2185676A1 CA 2185676 CA2185676A CA2185676A1 CA 2185676 A1 CA2185676 A1 CA 2185676A1 CA 2185676 CA2185676 CA 2185676 CA 2185676 A CA2185676 A CA 2185676A CA 2185676 A1 CA2185676 A1 CA 2185676A1
- Authority
- CA
- Canada
- Prior art keywords
- composition
- weight
- composition according
- rubber
- sand
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/10—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C04B26/16—Polyurethanes
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C7/00—Coherent pavings made in situ
- E01C7/08—Coherent pavings made in situ made of road-metal and binders
- E01C7/30—Coherent pavings made in situ made of road-metal and binders of road-metal and other binders, e.g. synthetic material, i.e. resin
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/0075—Uses not provided for elsewhere in C04B2111/00 for road construction
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Ceramic Engineering (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Road Paving Structures (AREA)
Abstract
The invention provides a novel surfacing composition for ground areas which may be subjected to vehicular or heavy use traffic. The composition comprises rubber crumb (preferably from dust to small particles), crushed rock and sand held together with a binder of a single component, moisture-curing polyurethane. The composition is elastic, can be laid in a variety of climatic conditions, has good frictional adhesion, generates low surface noise, can be made water-permeable or-impermeable, and has a highly advantageous fragmentation action on surface ice and packed snow when subjected to vehicular traffic. A particular advantage of the composition of the invention is that it can be mixed in conventional equipment, for example in a conventional asphalt mixing plant, and can be laid using road surfacing equipment conventionally used in asphalt laying.
Description
~ W09~12s076 ~I ~35676 P.~ L73.
TITLE:
Road Surfacing Composition and Process DESCRIPTION:
Field of the Invention The invention relates to novel road surfacing compositions incorporating rubber crumb, and to processes in which they are used to surface or resurface roads. The term "roads" is used in this Specification to include highways, tracks, bridges, car parks and any other ground areas which may be subjected to vehicular or other heavy use traffic. The compositions of the invention can also be used to cover concrete paving slabs, and the 1nvention therefore also relates to a process for producing the surface-covered slabs and to the resulting covered slabs.
Background Art Asphalt is the most widely used modern surfacing composition for roads In its simplest form, asphalt consists of stone chippings bound together by bitumen.
The size of the chippings can be varied, down to a coarse sand, to control the surface texture of the laid asphalt.
The aggregate, whether it is stone or sand, is preheated in an asphalt plant, mixed thoroughly with molten bitumen, and then transported to site where it is spread and rolled. From the asphalt plant, the hot asphalt generally has a workable life of from six to ten hours before it becomes too cool and stifr to lay.
Modified asphalts have been proposed in which some of the aggregate is replaced by rubber crumb obtained from recycled comminuted automobile tyres. Other modified asphalts have been proposed in which the softening temperature of the bitumen binder has been modified. So--called "polymer modified asphalts" utili~e bitumen which has had blended therein an appropriate amount of a W0 9~l25076 2 1 8 5 6 7 6 r~ O
polymer, which is generally an ethylene vinyl acetate copolymer (EVA) or a styrene butadiene styrene copolymer tSBS). So-called "rubberized asphalt" has a proportion of rubber dissolved in the bitumen. That increases the softening point of the bitumen as well as ~cting as a filler. The product is, however, very expensive.
All of the above asphalts and modified asphalts=employ bitumen. Disadvantages assQciated with the use o~f bitumen are that the bitumen contains aromatic oils, which are known carcinogens; and that the ~sphalt softens in hot weather with a resulting tendency to lose the accuracy of an initially level surface. Also there is a~ loss of traction or "grip" in hot weather. In cold weather conditions asphalt hardens to an extent such that it may become brittle. In cold weather it also lQses its water repellency, and so offers little resistance to ice formation. In all temperature conditions, asphalt affords relatively little adhesion to the sub-base, and is prone to so-called_reflective cracking when subject to traffic loads, and thermal base movement. The need for repairs or resurfacing is therefore frequent.
The laying of asphalt must be completed while the bitumen is soft enough for the asphalt to be workable. This means that the mix has a finite working life, generally from 6 to 10 hours, as it is transported from the asphalt plant, where it is mixed hot, to the final site. It cannot generally be laid in very cold conditions.
Bitumen-free surface materials are known. Bare concrete is the most obvious example, used in road construction.
Rubber /rubber crumb compositions have also been proposed, however, for specialized applications other than road construction. Running tracks and sports arenas, for example, have been surfaced with compositions in which rubber crumb is bound together with a thermosetting or Wo 95125076 2 ~ 8 5 6 76 r~ c ~
ehemical curing rubber composition. This surface composition is unsuitable for road surfacing because the application process invol~es on-site mixing in small batches in a blade or paddle mixer, followed by a rapid spreading and levelling because of the charaeteristics of the binder curing process. Also the material components are particularly weather sensitive. In any case, the expense of the eomposition would make it entirely unsuitable for use in road construction.
There is therefore a need for a road surfacing composition which is economically viable, whieh ean be delivered premixed to a site or mixed on site and laid using techniques familier to those used to laying asphalt, which has lmproved wear characteristics as eompared with asphalt, and which is bitumen-free. There is alsQ a need for a road surfaeing composition which avoids as far as possible problems associated with the fo'rmation of surfaee ice or packed snow. An elastic or resiliently deformable surfacing eomposition is potentlally advantageous in this regard beeause deformation of the road surfaee under traffic loads will be aceompanied by fragmentation of any surfaee iee or paeked snow. The ice- or snow will: then be more easily dispersi bl e .
The Invention The invention provides a road surfacing composition eomprising erushed stone or roek, small rubber pieees (rubber dust to rubber erumb) and sand bonded together with a single eomponent, moisture-hardening polyurethane.
The eomposition has elastic and water-repellant properties even in freezing eonditions, and the surfaee elasticity under traffie loads eauses fragmentation of any surfaee iee that may have formed.
The weight ratio of roek : rubber pieees : sand W09~ 076 ~1 ~5676 P~ c~ I O
polyurethane is preferably substantially 1:1:1:1. The rubber pieces preferably include both pieces of 1 mm and less, and pieces of 2 mm ana more.
In a preferred form, the invention provides a road surfacing composition comprising:
[A] from 10% to 50% by weight of rubber granules of 2 mm to 8 mm mesh size [B] from 0% to 10¦0 by weight of rubber granules of a size from dust to 2 mm mesh size ~ ~
[C] from 6% I;o 4010 by weight of crushed rock~ of 2 mm to 20 mm mesh size ~ D~ fro~ 10%~to 5~D/o by weight of sand~and [E] from 8% to 30~10 by weight of a single component, moisture curing polyurethane binder comprising:
a polyol in admixture with a di-isocyanate, or a prepolymer obtained therefrom, optionally in combination with one or more polymerization catalysts and/or additives .
Further discussion of preferred to optimum parameters of the various components is as follows:
Rubber granules Two size ranges of rubber granules are specified. The larger sized granules are preferably in the size range of 2 mm to 4 mm, and advantageously comprise from 10% to 25%
by weight of the composition. The smaller sized granules, from dust to 2 mm mesh size, may be omitted entirely ( the 0% lower limit ) bu~ preferably comprise from 2% to 1 0b by weight of the composition. The rubber granules may be recycled rubber crumb for example from comminuted automobile tyres, or may be granules or EPDM rubber. The latter permits the final road surfacing to be self--coloured in colours other than black.
w09~ 076 2 ~ 85 ~ 76 r~ 7~
Crushed Rock Hard aggregate of crushed granite or similar hard rock having an angular or subangular shape is preferred. The particle size is preferably from 2 mm to 13 mm mesh size, more preferably from 2 mm to 6 mm mesh size. Although the polyurethane binder contributes very significantly to the oustanding strength of the final road coverlng, the interlocking action of angular stone particles under compaction adds substantial further structure strength and stability. The crushed rock preferably comprises from 15% to 35~¦0, more preferably from 20% to 31%, by weight of the composition.
Sand The sand used should preferably be relatively clean, uniform in composition and with a high silica content.
Sand with a low iron content is preferred, so as to avoid redox reactions. The type of sand, by way of its composition and surface area, determines the optimum proportion of polyurethane binder that is used. The sand preferably has a mesh size of less than 2 mm, and preferably comprises from 25% to 40% by weight of the composition .
Polyurethane binder The optimum amount of polyurethane binder composition used, within the stated limits, is such that all particles in the composition are evenly covered with the binder. In that way the polyurethane binder acts as a bridge within the construction between all particles.
Free or surplus polyurethane in excess of the amount needed to encapsulate the particulate ingredients of the composition is preferably kept to a minimum.
The polyurethane binder may be, for example, a mixture or prepolymer of a polypropylene glycol and diphenylmethane di-isocyanate, together with optional additives and/or WO951,5076 2~1 ~5676 -6- PCT/GB95/00581 O
catalysts as discussed below Suc~ a mixIure is moisture--curing, and yet has a high tolerance of e~ccess water.
Therefore it can be laid on road surfaces which are not totally dry, although very wet surfaces should be avoided. Similarly laying in rain should be avoided, as the curing process involves the release of carbon dioxide which could become trapped under a cured surface skin, causing blistering, if the surface were to be exposed to exc~ssive moisture immediately arter laying.
Instead~of polypropylene glycol, the polyol component of the polyurethane binder may be a polyester based polyol, although that would tend to be more viscous at room temperature Additives Additives in the mixture are important to control the chemical reaction, to desensitize the components of the mixture, and to improve bonding and adhesion. In ideal conditions of temperature and moisture the additive may be reduced significantly in amount or even omitted. A
very small amount of an amine-terminated silane (preferably less than 0.5/0 by weight and advantageously less than 0.14% by weight of the polyurethane binder) is advantageous for a number of reasons. In the first place it accelerates the curing process. Secondly it acts as an adhesion agent which helps the chemical bonding that takes place between the stone and sand on the one hand and the polyurethane binder on the other. Ionic bonds are formed, both between the stone and sand in the composition and the polyurethane and in many cases between the polyurethane and the ground surface (scraped or worn asphalt or concrete) on which the composition of the invention is laid. Thirdly the additive reduces the amount of carbon dioxide given off during curing, by acting as a water-scavenger and offering extra amino groups for the cross-linkin~. A suitable amine-terminated WO 95l25076 2 1 8 5 6 7 6 r~
silane is that sold by Union Carbide Inc under the Trade Mark UNION CARBIDE ISO-A 1100 .
Catalyst The addition of a catalyst to the polyurethane binder, to assist curing, may be advantageous. A tin carboxylate, such as tin dilaurate, is preferred. Dibutyltin dilaurate, for example, is sold under the Trade Mark DABCO T12CL by Air Products and Chemicals, Inc. The amount of catalyst needed is not large; less than 0.1% by weight of the polyurethane binder is generally sufficient The catalyst accelerates the curing process very conslderably, and the optimum amount of catalyst varies -depending on the laying conditions, and in particular the ambient temperature and relative humidity of the weather. On a very hot, humid day for example it may be preferred to avoid the use of a catalyst altogether so as to counteract a naturally shortened curing period.
It may be desirable to use a catalyst containing no metal, in which case an oligomeric diamine such as polytetramethyleneoxide-di-p-aminobenzoate is suitable Such a diamine is sold under the Trade Mark VERSALINK
P1000 by Air Products and Chemicals Inc.
Mixing and Laying Procedure The ingredients of the composition are preferably premixed in a pug mill type asphalt batch plant, but could if desired be mixed cold at the laying site. Prior to mixing the asphalt plant should be cleaned as far as possible with hot, dry, abrasive aggregate mixed for several minutes. The residue should be examined and further mixings take place until it can be osberved that there is not any significant levels of bitumen.
Sand and aggregate can be fed into the mixer at W09s/2s076 2 1 8 5 6 7 6 -8- PCT/GB9510ffS81 temperatures up to 150C, subJect to the degree of moisture content of the aggregate. Predried aggregate or aggregate with a moiskure content below 5% would require relat' vely low feed-in temperatures. The rubber crumb and rubber dust is fed in at ambient temperature.
It has been found advantageous to distribute the additives and catalyst for the polyurethane binder through the solid components of the composition before the liquid polyurethane binder is added to the~ mlxture.
This ensures uniform distribution of the catalyst and good intimate contact between the additive or additives and the solid particulate matter, and is preferably achieved as follows. The liquid additive or additives and the catalyst are first intimately mixed with a small quantity (preferably a few kilograms) of dry sand and rubber dust. The quantity of liquid so added does not noticeably affect the free-flowing behaviour of the sand and rubber dust premixture, which is then introduced into the mixing box of the pug mill and distributed, together with the additive i s ) and catalyst, throughout the mix .
Catalyst and additive free polyurethane, already premixed to the required formulati~n, is free flowing and is fed into the mixing box without any preheating or need to be maintained at other than ambient temperature.
The polyurethane is initially very fluid and of low viscosity. It has good coating ability but preliminary cure reactions will become apparent as a result of the moisture content within the other ingredients and general humidity. The viscosity will increase as a result and thorough mixing should continue to ensure homogeneity.
Trial batches can determine the optimum mix time, which will again be dependent upon the ingredient proportions affected by the sand type and the general efficiency of the plant being used and, of course, the size of the , . . _ . , . _ . _ _ _ ~
WO 9~/2507(i 2 1 8 5 6 7 6 r~ ,Sl - l batch. Generally a brief mix of up to 2 to 3 minutes will De required.
The manufactured material should be dropped onto a clean, flat storage platform or delivery vehicle, the deck of which may be lightly coated with a solvent or paraffinic oil to prevent excessive adhesion. Alternatively it has been found perfectly feasible to store the composition in clean dry polythene bags which are filled and sealed immediately after mixing Because the polythene bags exclude atmospheric moisture which is essential for curing the polyurethane binder, the mix has an extended storage life before curing takes place. Bagged compositions have been stored for up to 30 days -~ithout deterioration, and have cured satisfactorily by applying a fine mist spray of water after spreading.
From the delivery vehicle, the material can be loaded into a standard or mini paving machine with the screed bars set to the required depth. The minimum permitted depth may be dictated by the paving machine or by the size of stone particles used in the composition, and the maximum permitted depth may be dictated by the need for atmospheric moisture to permeat all through the laid composition to effect curing. That in turn will be affected by the ambient relative humidity and by the degree of compaction after spreading. In general, laid depths of 10 mm to over 30 mm are easily attainable, with about 30 mm providing a reasonable general purpose covering. It is of course not necessary to spread the composition by a paving machine: it could alternatively be raked f lat by hand .
Whilst it is not essential for the road surface to be completely dry, there should not be standing water or water of any measurable quantity. A small degree of moisture, however, will enhance the bottom layer cure and .
WO 9~/25076 2 1 8 5 ~ ~ 6 PCT/GB95100581 O
_ 1 0--promote steadrast adhesion The road surface is preferably pre-coated with a primer of a polyurethane or epoxy resin adhesive.
Damaged road areas should he repaired to level prior to laying. ~oad surrace planing can take place~ t~o level in preparation for laying operations as required.
Edge detail may be manipulated by hand manually if required .
The composition may be laid as a porous~, water-permeable surface covering or as an ~impermeable surface covering.
For the former, a good proportion of larger sized crushed rock (component [C] ) and the omission of the smaller sized rubber granules (component [B~) can produce a suitable porous texture. The resulting road covering rapidly drains and disperses surface water leaving the road clear of standing water even in very heavy rainfall_ It minimizes splashback even in torrential rain. The surface is applied Dn top of a porous or impermeable base constructed to a crossfall to allow accumulated water to drain to the edge In the majority of applications, however, it is anticipated that the composition will be laid as a ~ater--impermeable road covering, in which case reas~Dnable cross falls should always be recognized given the impermeability and high water repellancy of the finished surface material. As such, good drainage and soakaways are important to prevent back-ups of standing water.
F~olling of the surface with a roller but avoiding waving effects will assist in providing mechanical interlocking of the aggregate and rubber components within the binder, and assist surface bonding.
W09sl2s076 21 85 676 r~ L~
The high proportions of larger size aggregate and rubber crumb help to give a surface texture to reduce wet weather skid. The asperities of the texture can be supplemented by further texturing operations. Brush techniques may be possible which will be across the road from crown to edge and generally in accordance with the water run off gradient. Also, surface dressinc~ can be applied if required, with a thin coating of binder (bituminous or polymeric) and broadcast with stone chips.
The surface itself creates a different road noise to standard asphalt and this is further enhanced by any surface texturing operations. The road noise can thus assist in alerting drivers of dangers areas, junctions, etc The noise and vibration absorbing features of the surface provide further benefits.
Generally, after 6 to 8 hours, the surface is moderately load bearing and can be walked upon for further work operations to take place, such as road marking operations. The material will generally be cured after 24 hours and capable of withstanding vehicular traffic, subject to suitable curing conditions of temperature, humidity and correct mixing.
The material should not be laid in ~evere cold conditions as the application and proportions of catalyst to counter the slow cure rate in extreme cold can pose too great a difficulty to handle efficiently. However a successful trial was carried out when the road and air temperatures were about 0C, and the subsequent overnight temperature dropped to about -8C. Laying of asphalt would have been impossible in those conditions, but the road surface laid according to the invention was properly laid and suffered no significant adverse effects from the relatively low temperatures .
WO 9S/25076 ~ 1 8 5 6 7 b PCT/GB9~/OOS81 The composition of the invention, when laid and cured, provides a v-ery durable road surface ~hich has a high inherent structural strength, bonds well to the surface on which it is laid (particularly to concrete~ and has an outstanding stability through extremes of temperatures.
It shows no serious adverse performance characteristics either at temperatures so cold that asphalt would tend to become brittle and crack, or at temperatures so hQt that asphalt would tend to deform or creep under traffic loads. It is far less dense than asphalt and is therefore extremely suitable for covering the road surfaces of bridges and elevated highways. In that respect its physical adhesion to concrete is of immense~advantage.
Another potential use for the composition of the invention is in the manufacture of surface-coated paving slabs which can be pre-coated with the composition of the invention and then handled and laid as conventional concrete paving slabs.
The following Examples illustrate the invention.
Example 1 A composition according to the invention had the following content by weight:
2 mm to 4 mm rubber granules 20%
2 mm to dust rubber granules 3%
2 mm to 6 mm crushed rock 28%
sharp sand 30%
polyurethane binder 19%
The rubber was recycled rubber crumb obtained from the comminution of automobile tyres. The crushed rock was granite. The sand was a clean sharp silica sand with a high silica content and a low iron content The polyurethane was a polypropylene glycol/diphenylmethane di-isocyanate prepolymer, which is a single component, WO9sl2s076 2 1 ~ 5676 }~
moisture curing rubber.
The composition was mixed in a pug mill type asphalt plant which had previously been thoroughly cleaned to remove bitumen residues. The sand and crushed rock had been pre-dried and stored outside, and were cold-mixed with the rubber crumb in 2000 kg (approx. ) batches. A few kilograms of the sand and rubber crumb dust were separately mixed together, and about 1 . 4 grams of dibutyltin dilaurate and about 3 . 0 grams of an organo aminosilane were added to that mixture and thoroughly dispersed through the mixture by mixing. The resulting premixture was added to each 2000 kg batch of solids, to obtain a substantially uniform distribution of the catalyst ( 0 . 07% by weight ) and additive ( 0 .15% by weight ) over the surface of the solids in the mill. The polyurethane binder was then added at ambient temperature and mixed with the solids in the mill for a total mixing time of about 90 seconds. No catalysts or additives were added to the polyurethane binder, other than those already added to the batch of solids in the mill.
After mixing, the composition was transported to the intended laying site, which was an asphalt-covered road the surface of which had been planed. On site, the ground temperature was about 0C. The surface had been primed with concentrated polyurethane.
The composition was transferred to a mini paving machine.
The composition was then immediately spread by the paving machine to a depth of 15 mm, and rolled to a compact finish .
After 8 hours the road was firm enough to be marked out with white lines, and after 16 hours was suitable for use by vehicular traffic.
_ _ Wo95/25076 2 1 8S676 ~ 0~ 1 0 A core sample section was cut and lifted from the road surface after three days and examined for bonding strength compaction and evenness of cure. The core sample was ,~udged to be very good in all of these respects.
Example 2 Using the same techniques of mixing a9 de5cribed in Example 1, the composition was varied as follows:
2 mm to 4 mm rubber granule9 12% by weight 1 mm to dust rubber granules 1 2D/~ by weight 2 mm to 6 mm crushed rock 28% by weight sharp sand 28% by weight polyurethane binder (as Example 1 ) 20% by weight dibutyltin dilaurate 0.06% by weight organo aminosilane ~ 0.10% by weight The polyurethane binder and mixing sequence was the same as in Example 1.
The mix was transported to site and then spread on an asphalt-covered road, the surface of which had been planed and primed with polyurethane. The mixture was spread manually by raking and lootlng. The material was then rolled to a compact finish.
After 8 hours the road surface was firm enough for moderate loads and aI ter 24 hours was judged to be firm enough for vehicular traffic. A sample was cut and lifted from the road after several months and showed no discernible signs of wear.
Example 3 Example 2 was repeated but using the following formulation for the composition:
.. . ... , _ W0~5~5076 2185676 r~ D~sr~
TITLE:
Road Surfacing Composition and Process DESCRIPTION:
Field of the Invention The invention relates to novel road surfacing compositions incorporating rubber crumb, and to processes in which they are used to surface or resurface roads. The term "roads" is used in this Specification to include highways, tracks, bridges, car parks and any other ground areas which may be subjected to vehicular or other heavy use traffic. The compositions of the invention can also be used to cover concrete paving slabs, and the 1nvention therefore also relates to a process for producing the surface-covered slabs and to the resulting covered slabs.
Background Art Asphalt is the most widely used modern surfacing composition for roads In its simplest form, asphalt consists of stone chippings bound together by bitumen.
The size of the chippings can be varied, down to a coarse sand, to control the surface texture of the laid asphalt.
The aggregate, whether it is stone or sand, is preheated in an asphalt plant, mixed thoroughly with molten bitumen, and then transported to site where it is spread and rolled. From the asphalt plant, the hot asphalt generally has a workable life of from six to ten hours before it becomes too cool and stifr to lay.
Modified asphalts have been proposed in which some of the aggregate is replaced by rubber crumb obtained from recycled comminuted automobile tyres. Other modified asphalts have been proposed in which the softening temperature of the bitumen binder has been modified. So--called "polymer modified asphalts" utili~e bitumen which has had blended therein an appropriate amount of a W0 9~l25076 2 1 8 5 6 7 6 r~ O
polymer, which is generally an ethylene vinyl acetate copolymer (EVA) or a styrene butadiene styrene copolymer tSBS). So-called "rubberized asphalt" has a proportion of rubber dissolved in the bitumen. That increases the softening point of the bitumen as well as ~cting as a filler. The product is, however, very expensive.
All of the above asphalts and modified asphalts=employ bitumen. Disadvantages assQciated with the use o~f bitumen are that the bitumen contains aromatic oils, which are known carcinogens; and that the ~sphalt softens in hot weather with a resulting tendency to lose the accuracy of an initially level surface. Also there is a~ loss of traction or "grip" in hot weather. In cold weather conditions asphalt hardens to an extent such that it may become brittle. In cold weather it also lQses its water repellency, and so offers little resistance to ice formation. In all temperature conditions, asphalt affords relatively little adhesion to the sub-base, and is prone to so-called_reflective cracking when subject to traffic loads, and thermal base movement. The need for repairs or resurfacing is therefore frequent.
The laying of asphalt must be completed while the bitumen is soft enough for the asphalt to be workable. This means that the mix has a finite working life, generally from 6 to 10 hours, as it is transported from the asphalt plant, where it is mixed hot, to the final site. It cannot generally be laid in very cold conditions.
Bitumen-free surface materials are known. Bare concrete is the most obvious example, used in road construction.
Rubber /rubber crumb compositions have also been proposed, however, for specialized applications other than road construction. Running tracks and sports arenas, for example, have been surfaced with compositions in which rubber crumb is bound together with a thermosetting or Wo 95125076 2 ~ 8 5 6 76 r~ c ~
ehemical curing rubber composition. This surface composition is unsuitable for road surfacing because the application process invol~es on-site mixing in small batches in a blade or paddle mixer, followed by a rapid spreading and levelling because of the charaeteristics of the binder curing process. Also the material components are particularly weather sensitive. In any case, the expense of the eomposition would make it entirely unsuitable for use in road construction.
There is therefore a need for a road surfacing composition which is economically viable, whieh ean be delivered premixed to a site or mixed on site and laid using techniques familier to those used to laying asphalt, which has lmproved wear characteristics as eompared with asphalt, and which is bitumen-free. There is alsQ a need for a road surfaeing composition which avoids as far as possible problems associated with the fo'rmation of surfaee ice or packed snow. An elastic or resiliently deformable surfacing eomposition is potentlally advantageous in this regard beeause deformation of the road surfaee under traffic loads will be aceompanied by fragmentation of any surfaee iee or paeked snow. The ice- or snow will: then be more easily dispersi bl e .
The Invention The invention provides a road surfacing composition eomprising erushed stone or roek, small rubber pieees (rubber dust to rubber erumb) and sand bonded together with a single eomponent, moisture-hardening polyurethane.
The eomposition has elastic and water-repellant properties even in freezing eonditions, and the surfaee elasticity under traffie loads eauses fragmentation of any surfaee iee that may have formed.
The weight ratio of roek : rubber pieees : sand W09~ 076 ~1 ~5676 P~ c~ I O
polyurethane is preferably substantially 1:1:1:1. The rubber pieces preferably include both pieces of 1 mm and less, and pieces of 2 mm ana more.
In a preferred form, the invention provides a road surfacing composition comprising:
[A] from 10% to 50% by weight of rubber granules of 2 mm to 8 mm mesh size [B] from 0% to 10¦0 by weight of rubber granules of a size from dust to 2 mm mesh size ~ ~
[C] from 6% I;o 4010 by weight of crushed rock~ of 2 mm to 20 mm mesh size ~ D~ fro~ 10%~to 5~D/o by weight of sand~and [E] from 8% to 30~10 by weight of a single component, moisture curing polyurethane binder comprising:
a polyol in admixture with a di-isocyanate, or a prepolymer obtained therefrom, optionally in combination with one or more polymerization catalysts and/or additives .
Further discussion of preferred to optimum parameters of the various components is as follows:
Rubber granules Two size ranges of rubber granules are specified. The larger sized granules are preferably in the size range of 2 mm to 4 mm, and advantageously comprise from 10% to 25%
by weight of the composition. The smaller sized granules, from dust to 2 mm mesh size, may be omitted entirely ( the 0% lower limit ) bu~ preferably comprise from 2% to 1 0b by weight of the composition. The rubber granules may be recycled rubber crumb for example from comminuted automobile tyres, or may be granules or EPDM rubber. The latter permits the final road surfacing to be self--coloured in colours other than black.
w09~ 076 2 ~ 85 ~ 76 r~ 7~
Crushed Rock Hard aggregate of crushed granite or similar hard rock having an angular or subangular shape is preferred. The particle size is preferably from 2 mm to 13 mm mesh size, more preferably from 2 mm to 6 mm mesh size. Although the polyurethane binder contributes very significantly to the oustanding strength of the final road coverlng, the interlocking action of angular stone particles under compaction adds substantial further structure strength and stability. The crushed rock preferably comprises from 15% to 35~¦0, more preferably from 20% to 31%, by weight of the composition.
Sand The sand used should preferably be relatively clean, uniform in composition and with a high silica content.
Sand with a low iron content is preferred, so as to avoid redox reactions. The type of sand, by way of its composition and surface area, determines the optimum proportion of polyurethane binder that is used. The sand preferably has a mesh size of less than 2 mm, and preferably comprises from 25% to 40% by weight of the composition .
Polyurethane binder The optimum amount of polyurethane binder composition used, within the stated limits, is such that all particles in the composition are evenly covered with the binder. In that way the polyurethane binder acts as a bridge within the construction between all particles.
Free or surplus polyurethane in excess of the amount needed to encapsulate the particulate ingredients of the composition is preferably kept to a minimum.
The polyurethane binder may be, for example, a mixture or prepolymer of a polypropylene glycol and diphenylmethane di-isocyanate, together with optional additives and/or WO951,5076 2~1 ~5676 -6- PCT/GB95/00581 O
catalysts as discussed below Suc~ a mixIure is moisture--curing, and yet has a high tolerance of e~ccess water.
Therefore it can be laid on road surfaces which are not totally dry, although very wet surfaces should be avoided. Similarly laying in rain should be avoided, as the curing process involves the release of carbon dioxide which could become trapped under a cured surface skin, causing blistering, if the surface were to be exposed to exc~ssive moisture immediately arter laying.
Instead~of polypropylene glycol, the polyol component of the polyurethane binder may be a polyester based polyol, although that would tend to be more viscous at room temperature Additives Additives in the mixture are important to control the chemical reaction, to desensitize the components of the mixture, and to improve bonding and adhesion. In ideal conditions of temperature and moisture the additive may be reduced significantly in amount or even omitted. A
very small amount of an amine-terminated silane (preferably less than 0.5/0 by weight and advantageously less than 0.14% by weight of the polyurethane binder) is advantageous for a number of reasons. In the first place it accelerates the curing process. Secondly it acts as an adhesion agent which helps the chemical bonding that takes place between the stone and sand on the one hand and the polyurethane binder on the other. Ionic bonds are formed, both between the stone and sand in the composition and the polyurethane and in many cases between the polyurethane and the ground surface (scraped or worn asphalt or concrete) on which the composition of the invention is laid. Thirdly the additive reduces the amount of carbon dioxide given off during curing, by acting as a water-scavenger and offering extra amino groups for the cross-linkin~. A suitable amine-terminated WO 95l25076 2 1 8 5 6 7 6 r~
silane is that sold by Union Carbide Inc under the Trade Mark UNION CARBIDE ISO-A 1100 .
Catalyst The addition of a catalyst to the polyurethane binder, to assist curing, may be advantageous. A tin carboxylate, such as tin dilaurate, is preferred. Dibutyltin dilaurate, for example, is sold under the Trade Mark DABCO T12CL by Air Products and Chemicals, Inc. The amount of catalyst needed is not large; less than 0.1% by weight of the polyurethane binder is generally sufficient The catalyst accelerates the curing process very conslderably, and the optimum amount of catalyst varies -depending on the laying conditions, and in particular the ambient temperature and relative humidity of the weather. On a very hot, humid day for example it may be preferred to avoid the use of a catalyst altogether so as to counteract a naturally shortened curing period.
It may be desirable to use a catalyst containing no metal, in which case an oligomeric diamine such as polytetramethyleneoxide-di-p-aminobenzoate is suitable Such a diamine is sold under the Trade Mark VERSALINK
P1000 by Air Products and Chemicals Inc.
Mixing and Laying Procedure The ingredients of the composition are preferably premixed in a pug mill type asphalt batch plant, but could if desired be mixed cold at the laying site. Prior to mixing the asphalt plant should be cleaned as far as possible with hot, dry, abrasive aggregate mixed for several minutes. The residue should be examined and further mixings take place until it can be osberved that there is not any significant levels of bitumen.
Sand and aggregate can be fed into the mixer at W09s/2s076 2 1 8 5 6 7 6 -8- PCT/GB9510ffS81 temperatures up to 150C, subJect to the degree of moisture content of the aggregate. Predried aggregate or aggregate with a moiskure content below 5% would require relat' vely low feed-in temperatures. The rubber crumb and rubber dust is fed in at ambient temperature.
It has been found advantageous to distribute the additives and catalyst for the polyurethane binder through the solid components of the composition before the liquid polyurethane binder is added to the~ mlxture.
This ensures uniform distribution of the catalyst and good intimate contact between the additive or additives and the solid particulate matter, and is preferably achieved as follows. The liquid additive or additives and the catalyst are first intimately mixed with a small quantity (preferably a few kilograms) of dry sand and rubber dust. The quantity of liquid so added does not noticeably affect the free-flowing behaviour of the sand and rubber dust premixture, which is then introduced into the mixing box of the pug mill and distributed, together with the additive i s ) and catalyst, throughout the mix .
Catalyst and additive free polyurethane, already premixed to the required formulati~n, is free flowing and is fed into the mixing box without any preheating or need to be maintained at other than ambient temperature.
The polyurethane is initially very fluid and of low viscosity. It has good coating ability but preliminary cure reactions will become apparent as a result of the moisture content within the other ingredients and general humidity. The viscosity will increase as a result and thorough mixing should continue to ensure homogeneity.
Trial batches can determine the optimum mix time, which will again be dependent upon the ingredient proportions affected by the sand type and the general efficiency of the plant being used and, of course, the size of the , . . _ . , . _ . _ _ _ ~
WO 9~/2507(i 2 1 8 5 6 7 6 r~ ,Sl - l batch. Generally a brief mix of up to 2 to 3 minutes will De required.
The manufactured material should be dropped onto a clean, flat storage platform or delivery vehicle, the deck of which may be lightly coated with a solvent or paraffinic oil to prevent excessive adhesion. Alternatively it has been found perfectly feasible to store the composition in clean dry polythene bags which are filled and sealed immediately after mixing Because the polythene bags exclude atmospheric moisture which is essential for curing the polyurethane binder, the mix has an extended storage life before curing takes place. Bagged compositions have been stored for up to 30 days -~ithout deterioration, and have cured satisfactorily by applying a fine mist spray of water after spreading.
From the delivery vehicle, the material can be loaded into a standard or mini paving machine with the screed bars set to the required depth. The minimum permitted depth may be dictated by the paving machine or by the size of stone particles used in the composition, and the maximum permitted depth may be dictated by the need for atmospheric moisture to permeat all through the laid composition to effect curing. That in turn will be affected by the ambient relative humidity and by the degree of compaction after spreading. In general, laid depths of 10 mm to over 30 mm are easily attainable, with about 30 mm providing a reasonable general purpose covering. It is of course not necessary to spread the composition by a paving machine: it could alternatively be raked f lat by hand .
Whilst it is not essential for the road surface to be completely dry, there should not be standing water or water of any measurable quantity. A small degree of moisture, however, will enhance the bottom layer cure and .
WO 9~/25076 2 1 8 5 ~ ~ 6 PCT/GB95100581 O
_ 1 0--promote steadrast adhesion The road surface is preferably pre-coated with a primer of a polyurethane or epoxy resin adhesive.
Damaged road areas should he repaired to level prior to laying. ~oad surrace planing can take place~ t~o level in preparation for laying operations as required.
Edge detail may be manipulated by hand manually if required .
The composition may be laid as a porous~, water-permeable surface covering or as an ~impermeable surface covering.
For the former, a good proportion of larger sized crushed rock (component [C] ) and the omission of the smaller sized rubber granules (component [B~) can produce a suitable porous texture. The resulting road covering rapidly drains and disperses surface water leaving the road clear of standing water even in very heavy rainfall_ It minimizes splashback even in torrential rain. The surface is applied Dn top of a porous or impermeable base constructed to a crossfall to allow accumulated water to drain to the edge In the majority of applications, however, it is anticipated that the composition will be laid as a ~ater--impermeable road covering, in which case reas~Dnable cross falls should always be recognized given the impermeability and high water repellancy of the finished surface material. As such, good drainage and soakaways are important to prevent back-ups of standing water.
F~olling of the surface with a roller but avoiding waving effects will assist in providing mechanical interlocking of the aggregate and rubber components within the binder, and assist surface bonding.
W09sl2s076 21 85 676 r~ L~
The high proportions of larger size aggregate and rubber crumb help to give a surface texture to reduce wet weather skid. The asperities of the texture can be supplemented by further texturing operations. Brush techniques may be possible which will be across the road from crown to edge and generally in accordance with the water run off gradient. Also, surface dressinc~ can be applied if required, with a thin coating of binder (bituminous or polymeric) and broadcast with stone chips.
The surface itself creates a different road noise to standard asphalt and this is further enhanced by any surface texturing operations. The road noise can thus assist in alerting drivers of dangers areas, junctions, etc The noise and vibration absorbing features of the surface provide further benefits.
Generally, after 6 to 8 hours, the surface is moderately load bearing and can be walked upon for further work operations to take place, such as road marking operations. The material will generally be cured after 24 hours and capable of withstanding vehicular traffic, subject to suitable curing conditions of temperature, humidity and correct mixing.
The material should not be laid in ~evere cold conditions as the application and proportions of catalyst to counter the slow cure rate in extreme cold can pose too great a difficulty to handle efficiently. However a successful trial was carried out when the road and air temperatures were about 0C, and the subsequent overnight temperature dropped to about -8C. Laying of asphalt would have been impossible in those conditions, but the road surface laid according to the invention was properly laid and suffered no significant adverse effects from the relatively low temperatures .
WO 9S/25076 ~ 1 8 5 6 7 b PCT/GB9~/OOS81 The composition of the invention, when laid and cured, provides a v-ery durable road surface ~hich has a high inherent structural strength, bonds well to the surface on which it is laid (particularly to concrete~ and has an outstanding stability through extremes of temperatures.
It shows no serious adverse performance characteristics either at temperatures so cold that asphalt would tend to become brittle and crack, or at temperatures so hQt that asphalt would tend to deform or creep under traffic loads. It is far less dense than asphalt and is therefore extremely suitable for covering the road surfaces of bridges and elevated highways. In that respect its physical adhesion to concrete is of immense~advantage.
Another potential use for the composition of the invention is in the manufacture of surface-coated paving slabs which can be pre-coated with the composition of the invention and then handled and laid as conventional concrete paving slabs.
The following Examples illustrate the invention.
Example 1 A composition according to the invention had the following content by weight:
2 mm to 4 mm rubber granules 20%
2 mm to dust rubber granules 3%
2 mm to 6 mm crushed rock 28%
sharp sand 30%
polyurethane binder 19%
The rubber was recycled rubber crumb obtained from the comminution of automobile tyres. The crushed rock was granite. The sand was a clean sharp silica sand with a high silica content and a low iron content The polyurethane was a polypropylene glycol/diphenylmethane di-isocyanate prepolymer, which is a single component, WO9sl2s076 2 1 ~ 5676 }~
moisture curing rubber.
The composition was mixed in a pug mill type asphalt plant which had previously been thoroughly cleaned to remove bitumen residues. The sand and crushed rock had been pre-dried and stored outside, and were cold-mixed with the rubber crumb in 2000 kg (approx. ) batches. A few kilograms of the sand and rubber crumb dust were separately mixed together, and about 1 . 4 grams of dibutyltin dilaurate and about 3 . 0 grams of an organo aminosilane were added to that mixture and thoroughly dispersed through the mixture by mixing. The resulting premixture was added to each 2000 kg batch of solids, to obtain a substantially uniform distribution of the catalyst ( 0 . 07% by weight ) and additive ( 0 .15% by weight ) over the surface of the solids in the mill. The polyurethane binder was then added at ambient temperature and mixed with the solids in the mill for a total mixing time of about 90 seconds. No catalysts or additives were added to the polyurethane binder, other than those already added to the batch of solids in the mill.
After mixing, the composition was transported to the intended laying site, which was an asphalt-covered road the surface of which had been planed. On site, the ground temperature was about 0C. The surface had been primed with concentrated polyurethane.
The composition was transferred to a mini paving machine.
The composition was then immediately spread by the paving machine to a depth of 15 mm, and rolled to a compact finish .
After 8 hours the road was firm enough to be marked out with white lines, and after 16 hours was suitable for use by vehicular traffic.
_ _ Wo95/25076 2 1 8S676 ~ 0~ 1 0 A core sample section was cut and lifted from the road surface after three days and examined for bonding strength compaction and evenness of cure. The core sample was ,~udged to be very good in all of these respects.
Example 2 Using the same techniques of mixing a9 de5cribed in Example 1, the composition was varied as follows:
2 mm to 4 mm rubber granule9 12% by weight 1 mm to dust rubber granules 1 2D/~ by weight 2 mm to 6 mm crushed rock 28% by weight sharp sand 28% by weight polyurethane binder (as Example 1 ) 20% by weight dibutyltin dilaurate 0.06% by weight organo aminosilane ~ 0.10% by weight The polyurethane binder and mixing sequence was the same as in Example 1.
The mix was transported to site and then spread on an asphalt-covered road, the surface of which had been planed and primed with polyurethane. The mixture was spread manually by raking and lootlng. The material was then rolled to a compact finish.
After 8 hours the road surface was firm enough for moderate loads and aI ter 24 hours was judged to be firm enough for vehicular traffic. A sample was cut and lifted from the road after several months and showed no discernible signs of wear.
Example 3 Example 2 was repeated but using the following formulation for the composition:
.. . ... , _ W0~5~5076 2185676 r~ D~sr~
3 mm to 8 mm rubber granules 12~ by weight 2 mm to dust rubber granules 12% by weight 5 mm crushed rock 8% by weight 13 mm crushed rock 10% by weight sand 38% by weight polyurethane binder 20% by weight dibutyltin dilaurate 0.06% by weight organo aminosilane 0.10% by weight The performance characteristics of the road coverings of Examples 2 and 3 were equal to those of Example 1. In particular, excellent adhesion was noted between the polyurethane binder and the crushed rock of the aggregate, and a better interlocking OL the crushed rock particles due to their larger particle size.
Example 4 A porous road surface was prepared as follows.
Mixing and laying techniques Or Example 1 were used to create a mix with the ~ollowing composition-2 mm to 8 mm rubber granules 22% by weight 5 mm crushed rock 16% by weight 13 mm crushed rock 15% by weight sand 30% by weight polyurethane binder 17% by weight dibutyltin dilaurate o.06% by weight organo aminosilane 0.15% by weight The road covering after laying was found to give a goodwater permeability, draining and dispersing rainwater even in heavy rain. The subsurface on which the road covering was laid had itself a good crossfall to assist the water dispersal.
W095~25076 218~676 r~ c~
After several weeks of vehicular traffic, the surface was exam.ined and was seen to be generally good.
Example 5 In this Example a differen~t mixing technique was used.
Instead of mixing the components in an asphalt mixer, they were batch mixed on site in relatively small quantities to resurface an asphalt driveway of which the asphalt surface was over seven years old.
The site was first prepared by roughly cleaning the old surface of moss and dirt by scraping and brushing, using a spa-de and a wire brush. A primer was then applied over the surface at a coverage= r~te of 50 grams per square metre. The primer consisted of 93~0 by wei~t methylated spirit, 2% by weight of water and 5% by weight of an organo aminosilane. The primer dried rapidly in the cold (3C) but windy conditions.
The surface composition was mixed in three batches in a large polypropylene drum. The ratio of components was as follows:
rubber crumb 23.5% by weight 2 mm crushed rock 24.5% by weight 5 mm to 6 mm crushed rock 2.5% by weight high silica sand ~ 29.5% by wei~ht polyurethane binder 20 . 0% by weight dilbutyltin carboxylate O.o8% by weight organo aminosilane 0.17% by weight The rubber crumb was predominately in the size range of 2 mm to 6 mm, although they contained a small amount (less than 10% by weight ~ of smaller particles, down to dust .
The rubber crumb and 2 mm and 5-6 mm crushed rock was fed WO 95/2~076 2 t 8 5 6 7 6 r~ sO-into the drum. The sand was added at about 150C, and the contents of the drum were rapidly mixed with an electric spiral mixing rod. The organo aminosilane was added, and a slight haze or smoke was observed over the drum as the additive contacted the hot sand. The tin dilaurate catalyst was then added, by which time the temperature of the mix had fallen to 50C. During mixing, care was taken continually to bring the sand to the top of the drum from the bottom.
It was observed that the sand and aggregate were not totally dry at the start. Small lumps of compacted sand and small portions of damp aggregate indicated significant moisture content in places. When thoroughly mixed, this was not noticeable and the overall mixture appeared dry.
The polyurethane binder was added while the mixed solids were still warm, and the mixture was warm and fluid and mixed easily. It took about 2 to 3 minutes for the polyurethane binder to become distributed through the entire mix.
The first mixed batch was poured over the prepared asphalt surface and roughly raked and looted, and left for an hour to settle, to cool and to be exposed to the atmosphere. During this time the second and third batches were similarly prepared and spread in adjacent bays. The coverage rate was about 17 kg per square metre at a minimum depth of 10 mm and an average depth significantly hi gher .
After about 1. 5 hours the material was trowelled smooth with a minimal degree of compaction. It was stiff and rather difficult to work manually due in part to the low air temperatures (2 to 3C~ and in part to the fact that it was raining slightly. After a further 3 hours there .... .. , .. . . _ _ , , _ _ , WO 9~l25076 2 1 ~ 5~6 7 6 PCTIGB95/00~81 0 were signs of gas exolution with slight surface blistering. At this stage the covering was compacted by rolling using a hand roller=the surface Pf which had been smeared lightly with a paraffinic oil to reduce sticking.
The weather deteriPrated into steady rain, and about 5 hours from the first mixing the surface was therefore covered with polythene sheeting to avoid too rapid a cur e .
After a further 13 hours the polythene sheeting was removed. An area that had been left uncovered held a pool of surface water ~which was swept away. The surface beneath that surface water showed no obviDus signs of deterioration. The surface was firm enough to be walked upon. After 20 hours a car was driven over l;he area without any sign of tyre depressions. After 40 hours a heavy car was driven over the area a number of times without any marks or damage to the surface. Repeated use of power steering to turn the vehicle wheels while the car was stationary caused no damage at all tQ the surface .
Example 6 A composition was prepared on a small batch scale from the components:
rubber crumb 25% by weight sand and small aggregate 55h by weight polyurethane binder 20h by weight organotin catalyst ~ 0.08% by weight amine-terminated organosilane 0.14% by weight The rubber crumb was primarily from 2 mm to 4 mm mesh size with a small proportion (no more than 10% by weight) of 2 mm to dust content. The sand and aggregate mixture contained about 50% by weight of 2 mm to 6 mm particles.
~ W0 95l2507(; ~ l 8 5~ 7 6 The additive and catalyst were premixed with a small quantity of the sand/aggregate before being uniformly dispersed through the mixture. After mixing, the composition could easily be spread over concrete paving slabs to a depth of 5 mm to 10 mm after compaction The paving was first primed, Aowever, to aid adhesion. The following four primers were used, all giving excellent resul ts .
(a) Each concrete paving slab was primed with a light mist spray of 5/0 by weight of the amine terminated organosilane dissolved ~ n industrial alcohol or methylated spirit. An applicatiQn rate of less than 100 grams of the primer solution per square metre was sufficient to provide a strong bond strength between the cured compositiQn and the concrete.
(b) Each concrete paving slab was primed with the same polyurethane binder as that of the surfacing composition, applied with a brush.
(c) Each slab was primed with the polyurethane binder diluted with 30% by weight of an organic solvent.
Both (b) and (c) resulted in virtually identical adhesion of the final cured coating.
(d) An epoxy adhesive was used as primer, with excellent results.
Example 7 The following components were used to prepare a composition for temporary storage in the open air before use .
Rubber granules 2 mm to ~ mm 23.8% by weight Rubber dust 2 . 0% by weight 6 mm stone chippings 20 . 5% by weight WO ~5/2507G 2 1 8 5 6 7 6 F~ll~,b~
2 mm stone chippings ( grit ~ = 5 . 0b by weight Sand ~ 30 . 0% by weight Polyurethane binder 18.7b by weight tin dilaurate 0 . 02% by weight aminosilane 0 . 08b by weight The rubber, sand and aggregate were heated to 150C in a clean asphalt mixer and thoroughly dried, and then the additive and catalyst mixed in, after prior distribution through a small quantity of dry sand. There was some smoking on the addition of the additive and catalyst, with evolution of a smal~amount of carbon monoxide and carbon dioxi~e Then the p!~lyurethane binder was added and the composition thoroughly mixed, before being discharged into a pi~e.
It was a dry summer ' s day with an ambient temperature of about 15~c. The composition remained workable for 8 hours without noticeable curing, but cured rapidly when spread and rolled as in Example 1, with a fine mist spray of water being applied after spreading but prior to rolling.
Example 8 The mixing procedure of Example 7 was repeated using the ~ame components and proportions except that the catalyst was 0 02% by weight of tin carboxylate and 0 03% by weight of tin dilaurate, and 0 14% by weight of amine--terminated or~;anosilane. Thorough drying of the solid components of the mixture was ensured by maintaining the temperature in the asphalt mixer at 150C for seven minutes longer than in Example 7.
After mixing, the composition was delivered into dry polythene bags which were immediately sealed. Samples were used at intervals over a period of 30 days, at the end of which period the composltion was still easily WO ~5125076 r.~
workable. Each sample was spread, moistened with a fine mist spray of water and then rolled. In each case the sample cured quickly, achieving a strength sufficient to take pedestrian and light vehicular traffic after 15 hours at 15 C .
Example 9 This Example illustrates the highly advantageous properties of the composition of the invention in conditions of snow and ice.
A road surface was resurfaced in strips according to the techniques of Example 2, with the exposed wear surface of the finished road alternating between strips of original asphalt about 300 mm wide and strips of the composition of the invention of similar width. The strips ran transversely to the road direction, so that vehicular traffic passed sequentially over the alternating asphalt and polyurethane-bound surfaces.
After a light fall of snow, the effect of traffic on the striated road surface was observed. Initial vehicular traffic tended to cause the packed snow to adhere to the asphalt surface but not to the surface of the composition of the invention. After continued exposure to traffic, the asphalt sections were fairly uniformly covered with a layer of highly compacted, firmly adherent and very slippery snow and ice. The sections surfaced with the composition of the invention were largely free from snow and ice.
The trial showed that when subjected to ~dentical conditions of temperature, snow fall and subsequent traffic, the surface composition of the invention provided by far the superior road surface which showed relatively little adhesion to snow and ice.
_ _ _ _ .
Example 4 A porous road surface was prepared as follows.
Mixing and laying techniques Or Example 1 were used to create a mix with the ~ollowing composition-2 mm to 8 mm rubber granules 22% by weight 5 mm crushed rock 16% by weight 13 mm crushed rock 15% by weight sand 30% by weight polyurethane binder 17% by weight dibutyltin dilaurate o.06% by weight organo aminosilane 0.15% by weight The road covering after laying was found to give a goodwater permeability, draining and dispersing rainwater even in heavy rain. The subsurface on which the road covering was laid had itself a good crossfall to assist the water dispersal.
W095~25076 218~676 r~ c~
After several weeks of vehicular traffic, the surface was exam.ined and was seen to be generally good.
Example 5 In this Example a differen~t mixing technique was used.
Instead of mixing the components in an asphalt mixer, they were batch mixed on site in relatively small quantities to resurface an asphalt driveway of which the asphalt surface was over seven years old.
The site was first prepared by roughly cleaning the old surface of moss and dirt by scraping and brushing, using a spa-de and a wire brush. A primer was then applied over the surface at a coverage= r~te of 50 grams per square metre. The primer consisted of 93~0 by wei~t methylated spirit, 2% by weight of water and 5% by weight of an organo aminosilane. The primer dried rapidly in the cold (3C) but windy conditions.
The surface composition was mixed in three batches in a large polypropylene drum. The ratio of components was as follows:
rubber crumb 23.5% by weight 2 mm crushed rock 24.5% by weight 5 mm to 6 mm crushed rock 2.5% by weight high silica sand ~ 29.5% by wei~ht polyurethane binder 20 . 0% by weight dilbutyltin carboxylate O.o8% by weight organo aminosilane 0.17% by weight The rubber crumb was predominately in the size range of 2 mm to 6 mm, although they contained a small amount (less than 10% by weight ~ of smaller particles, down to dust .
The rubber crumb and 2 mm and 5-6 mm crushed rock was fed WO 95/2~076 2 t 8 5 6 7 6 r~ sO-into the drum. The sand was added at about 150C, and the contents of the drum were rapidly mixed with an electric spiral mixing rod. The organo aminosilane was added, and a slight haze or smoke was observed over the drum as the additive contacted the hot sand. The tin dilaurate catalyst was then added, by which time the temperature of the mix had fallen to 50C. During mixing, care was taken continually to bring the sand to the top of the drum from the bottom.
It was observed that the sand and aggregate were not totally dry at the start. Small lumps of compacted sand and small portions of damp aggregate indicated significant moisture content in places. When thoroughly mixed, this was not noticeable and the overall mixture appeared dry.
The polyurethane binder was added while the mixed solids were still warm, and the mixture was warm and fluid and mixed easily. It took about 2 to 3 minutes for the polyurethane binder to become distributed through the entire mix.
The first mixed batch was poured over the prepared asphalt surface and roughly raked and looted, and left for an hour to settle, to cool and to be exposed to the atmosphere. During this time the second and third batches were similarly prepared and spread in adjacent bays. The coverage rate was about 17 kg per square metre at a minimum depth of 10 mm and an average depth significantly hi gher .
After about 1. 5 hours the material was trowelled smooth with a minimal degree of compaction. It was stiff and rather difficult to work manually due in part to the low air temperatures (2 to 3C~ and in part to the fact that it was raining slightly. After a further 3 hours there .... .. , .. . . _ _ , , _ _ , WO 9~l25076 2 1 ~ 5~6 7 6 PCTIGB95/00~81 0 were signs of gas exolution with slight surface blistering. At this stage the covering was compacted by rolling using a hand roller=the surface Pf which had been smeared lightly with a paraffinic oil to reduce sticking.
The weather deteriPrated into steady rain, and about 5 hours from the first mixing the surface was therefore covered with polythene sheeting to avoid too rapid a cur e .
After a further 13 hours the polythene sheeting was removed. An area that had been left uncovered held a pool of surface water ~which was swept away. The surface beneath that surface water showed no obviDus signs of deterioration. The surface was firm enough to be walked upon. After 20 hours a car was driven over l;he area without any sign of tyre depressions. After 40 hours a heavy car was driven over the area a number of times without any marks or damage to the surface. Repeated use of power steering to turn the vehicle wheels while the car was stationary caused no damage at all tQ the surface .
Example 6 A composition was prepared on a small batch scale from the components:
rubber crumb 25% by weight sand and small aggregate 55h by weight polyurethane binder 20h by weight organotin catalyst ~ 0.08% by weight amine-terminated organosilane 0.14% by weight The rubber crumb was primarily from 2 mm to 4 mm mesh size with a small proportion (no more than 10% by weight) of 2 mm to dust content. The sand and aggregate mixture contained about 50% by weight of 2 mm to 6 mm particles.
~ W0 95l2507(; ~ l 8 5~ 7 6 The additive and catalyst were premixed with a small quantity of the sand/aggregate before being uniformly dispersed through the mixture. After mixing, the composition could easily be spread over concrete paving slabs to a depth of 5 mm to 10 mm after compaction The paving was first primed, Aowever, to aid adhesion. The following four primers were used, all giving excellent resul ts .
(a) Each concrete paving slab was primed with a light mist spray of 5/0 by weight of the amine terminated organosilane dissolved ~ n industrial alcohol or methylated spirit. An applicatiQn rate of less than 100 grams of the primer solution per square metre was sufficient to provide a strong bond strength between the cured compositiQn and the concrete.
(b) Each concrete paving slab was primed with the same polyurethane binder as that of the surfacing composition, applied with a brush.
(c) Each slab was primed with the polyurethane binder diluted with 30% by weight of an organic solvent.
Both (b) and (c) resulted in virtually identical adhesion of the final cured coating.
(d) An epoxy adhesive was used as primer, with excellent results.
Example 7 The following components were used to prepare a composition for temporary storage in the open air before use .
Rubber granules 2 mm to ~ mm 23.8% by weight Rubber dust 2 . 0% by weight 6 mm stone chippings 20 . 5% by weight WO ~5/2507G 2 1 8 5 6 7 6 F~ll~,b~
2 mm stone chippings ( grit ~ = 5 . 0b by weight Sand ~ 30 . 0% by weight Polyurethane binder 18.7b by weight tin dilaurate 0 . 02% by weight aminosilane 0 . 08b by weight The rubber, sand and aggregate were heated to 150C in a clean asphalt mixer and thoroughly dried, and then the additive and catalyst mixed in, after prior distribution through a small quantity of dry sand. There was some smoking on the addition of the additive and catalyst, with evolution of a smal~amount of carbon monoxide and carbon dioxi~e Then the p!~lyurethane binder was added and the composition thoroughly mixed, before being discharged into a pi~e.
It was a dry summer ' s day with an ambient temperature of about 15~c. The composition remained workable for 8 hours without noticeable curing, but cured rapidly when spread and rolled as in Example 1, with a fine mist spray of water being applied after spreading but prior to rolling.
Example 8 The mixing procedure of Example 7 was repeated using the ~ame components and proportions except that the catalyst was 0 02% by weight of tin carboxylate and 0 03% by weight of tin dilaurate, and 0 14% by weight of amine--terminated or~;anosilane. Thorough drying of the solid components of the mixture was ensured by maintaining the temperature in the asphalt mixer at 150C for seven minutes longer than in Example 7.
After mixing, the composition was delivered into dry polythene bags which were immediately sealed. Samples were used at intervals over a period of 30 days, at the end of which period the composltion was still easily WO ~5125076 r.~
workable. Each sample was spread, moistened with a fine mist spray of water and then rolled. In each case the sample cured quickly, achieving a strength sufficient to take pedestrian and light vehicular traffic after 15 hours at 15 C .
Example 9 This Example illustrates the highly advantageous properties of the composition of the invention in conditions of snow and ice.
A road surface was resurfaced in strips according to the techniques of Example 2, with the exposed wear surface of the finished road alternating between strips of original asphalt about 300 mm wide and strips of the composition of the invention of similar width. The strips ran transversely to the road direction, so that vehicular traffic passed sequentially over the alternating asphalt and polyurethane-bound surfaces.
After a light fall of snow, the effect of traffic on the striated road surface was observed. Initial vehicular traffic tended to cause the packed snow to adhere to the asphalt surface but not to the surface of the composition of the invention. After continued exposure to traffic, the asphalt sections were fairly uniformly covered with a layer of highly compacted, firmly adherent and very slippery snow and ice. The sections surfaced with the composition of the invention were largely free from snow and ice.
The trial showed that when subjected to ~dentical conditions of temperature, snow fall and subsequent traffic, the surface composition of the invention provided by far the superior road surface which showed relatively little adhesion to snow and ice.
_ _ _ _ .
Claims (24)
1. A highway surfacing composition comprising crushed stone or rock, small rubber pieces in a size range from rubber dust to rubber crumb, and sand bonded together with a single component, moisture-hardening polyurethane, wherein the ratio by weight of rock: rubber pieces: sand: polyurethane is substantially 1:1:1:1.
2. A composition according to claim 1, wherein the small rubber pieces include both relatively small rubber pieces of 1 mm and less, and relatively large rubber pieces of 3 mm and more.
3. A highway surfacing composition comprising:
[A] from 10% to 50% by weight of rubber granules of 2 mm to 8 mm mesh size [B] from 0% to 10% by weight of rubber granules of a size from dust to 2 mm mesh size [C] from 6% to 40% by weight of crushed rock of 2 mm to 20 mm mesh size [D] from 10% to 50% by weight of sand and [E] from 8% to 30% by weight of a single component, moisture curing polyurethane binder comprising;
a polyol in admixture with a di-isocyanate, or a prepolymer obtained therefrom, optionally in combination with one or more polymerization catalysts and/or additives.
[A] from 10% to 50% by weight of rubber granules of 2 mm to 8 mm mesh size [B] from 0% to 10% by weight of rubber granules of a size from dust to 2 mm mesh size [C] from 6% to 40% by weight of crushed rock of 2 mm to 20 mm mesh size [D] from 10% to 50% by weight of sand and [E] from 8% to 30% by weight of a single component, moisture curing polyurethane binder comprising;
a polyol in admixture with a di-isocyanate, or a prepolymer obtained therefrom, optionally in combination with one or more polymerization catalysts and/or additives.
4. A composition according to claim 3, wherein the component [A] comprises rubber granules of from 2 mm to 4 mm mesh size.
5. A composition according to claim 3 or claim 4, wherein the component [Al comprises from 10% to 25% by weight of the composition.
6. A composition according to any of claims 3 to 5, wherein the component [B]
comprises from 2% to 10% by weight of the composition.
comprises from 2% to 10% by weight of the composition.
7. A composition according to any of claims 3 to 6, wherein the component [C]
comprises crushed rock of from 2 mm to 13 mm mesh size.
comprises crushed rock of from 2 mm to 13 mm mesh size.
8. A composition according to claim 7, wherein the component [C] comprises crushed rock of from 2 mm to 6 mm mesh size.
9. A composition according to any of claims 3 to 8, wherein the component [C]
comprises from 15% to 35% by weight of the composition.
comprises from 15% to 35% by weight of the composition.
10. A composition according to claim 9, wherein the component [C] comprises from 20% to 31% by weight of the composition.
11. A composition according to any of claims 3 to 10, wherein the component [D]
is sand with a mesh size of less than 2 mm.
is sand with a mesh size of less than 2 mm.
12. A composition according to any of claims 3 to 11, wherein the component [D]
comprises from 25% to 40% by weight of the composition.
comprises from 25% to 40% by weight of the composition.
13. A composition according to any of claims 3 to 12, wherein the rubber granules are recycled rubber crumb from comminuted automobile tyres.
14. A composition according to any of claims 3 to 12, wherein the rubber granules are granules of EPDM rubber.
15. A composition according to any of claims 3 to 14, wherein the polyurethane binder is a mixture of prepolymer of a polypropylene glycol and diphenyl methane diisocyanate.
16. A composition according to any of claims 3 to 14, wherein the polyurethane binder is a mixture or prepolymer of a polyester based polyol and diphenylmethane diisocyanate.
17. A composition according to any of claims 3 to 16, wherein the polyurethane binder contains an amine-terminated silane in an amount less than 0.5% by weightof the binder.
18. A composition according to any of claims 3 to 17, wherein the polyurethane binder contains a catalyst to assist curing.
19. A composition according to claim 18, wherein the catalyst is a tin carboxylate and is present in an amount less than 0.1% by weight of the binder.
20. A composition according to claim 19, wherein the catalyst is tin dilaurate.
21. A method of surfacing or resurfacing a highway using a composition accordingto any preceding claim, which comprises mixing the rubber crumb, crushed rock, sand and binder of the composition in an asphalt plant in which the rock and sand arepreheated; transporting the mixed composition to a site at which the highway surface is to be laid, spreading the composition over the surface, rolling it for compaction and allowing the polyurethane binder to cure under the action of atmospheric moisture.
22. A method according to claim 21, wherein a curing catalyst for the binder is added to the composition on site immediately before spreading and rolling.
23. A highway structure, such as a road, bridge or elevated highway, that has been surfaced with a composition according to any of claims 1 to 20.
24. A paving slab that has been surfaced with a composition according to any of claims 1 to 20.
Applications Claiming Priority (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6085204A JP2920814B2 (en) | 1994-03-17 | 1994-03-17 | Elastic road pavement |
| JP6/85204 | 1994-03-17 | ||
| JP6/165728 | 1994-06-14 | ||
| JP6165728A JP2920815B2 (en) | 1994-06-14 | 1994-06-14 | Elastic perforated pavement |
| JP6/198902 | 1994-07-20 | ||
| JP6198903A JP2920816B2 (en) | 1994-07-20 | 1994-07-20 | Elastic pavement method and elastic surface layer manufacturing method |
| JP6/198,903 | 1994-07-20 | ||
| JP19890294A JPH0827707A (en) | 1994-07-20 | 1994-07-20 | Elastic paving material and elastic paving method |
| GB95501115.1 | 1995-01-20 | ||
| GBGB9501115.1A GB9501115D0 (en) | 1995-01-20 | 1995-01-20 | Road surfacing composition and process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2185676A1 true CA2185676A1 (en) | 1995-09-21 |
Family
ID=27517278
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2185676 Abandoned CA2185676A1 (en) | 1994-03-17 | 1995-03-17 | Road surfacing composition and process |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0750595A1 (en) |
| AU (1) | AU2076495A (en) |
| CA (1) | CA2185676A1 (en) |
| WO (1) | WO1995025076A1 (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1287815B1 (en) * | 1996-07-09 | 1998-08-19 | Pescale Spa | MIXTURES TO DAMPEN VIBRATIONS AND SOUNDS SOLID IN THE GROUND AND IN BUILDINGS |
| EP0999193A1 (en) * | 1998-11-03 | 2000-05-10 | Horst Wustinger | Cementitious compound and concrete building element formed therefrom |
| JP4357029B2 (en) * | 1999-05-11 | 2009-11-04 | 大成ロテック株式会社 | Low noise elastic pavement and low noise elastic pavement construction method |
| DE19941527B4 (en) * | 1999-09-01 | 2006-02-09 | Heidelberger Bauchemie Gmbh Marke Deitermann | Two-building material system |
| FR2829487B1 (en) * | 2001-09-11 | 2004-08-20 | Rincent Btp Services Materiaux | MATERIAL BASED ON RUBBER AGGREGATES, MANUFACTURING METHOD AND USES THEREOF |
| DE202008004886U1 (en) * | 2008-04-08 | 2008-06-05 | Denso-Holding Gmbh & Co. | Curable mixture for sewer and road construction |
| DE102013007449A1 (en) * | 2013-05-02 | 2014-11-06 | Denso-Holding Gmbh & Co. | Traffic surface structure with at least one intermediate layer |
| GB2514847A (en) * | 2013-06-07 | 2014-12-10 | Enviromate Ltd | Construction material |
| US9663902B2 (en) | 2014-09-19 | 2017-05-30 | Quality Mat Company | Environmentally resistant encapsulated mat construction |
| US9714487B2 (en) | 2014-09-23 | 2017-07-25 | Quality Mat Company | Industrial mats with lifting elements |
| US9447547B2 (en) | 2014-09-23 | 2016-09-20 | Joe Penland, Jr. | Mat construction with environmentally resistant core |
| US9486976B1 (en) * | 2015-09-15 | 2016-11-08 | Quality Mat Company | Mat construction having environmentally resistant skin |
| US9617693B1 (en) | 2014-09-23 | 2017-04-11 | Quality Mat Company | Lifting elements for crane mats |
| US9476164B2 (en) | 2014-09-19 | 2016-10-25 | Quality Mat Company | Industrial mat having side bumpers and lifting elements |
| US9663903B2 (en) | 2014-09-23 | 2017-05-30 | Quality Mat Company | Industrial mats having plastic or elastomeric side members |
| US9822493B2 (en) | 2014-09-19 | 2017-11-21 | Quality Mat Company | Industrial mats having side protection |
| US20160258115A1 (en) | 2014-09-23 | 2016-09-08 | Joe Penland, Jr. | Industrial mats having cost effective core structures |
| US9863098B2 (en) | 2014-09-23 | 2018-01-09 | Quality Mat Company | Hybrid crane mat with lifting elements |
| US10273639B2 (en) | 2014-09-19 | 2019-04-30 | Quality Mat Company | Hybrid industrial mats having side protection |
| US9447548B2 (en) | 2014-09-19 | 2016-09-20 | Joe Penland, Jr. | Industrial mat with molded core and outer abuse surfaces |
| US9845576B2 (en) | 2014-09-23 | 2017-12-19 | Quality Mat Company | Hybrid crane mat utilizing various longitudinal members |
| US10753050B2 (en) | 2014-09-23 | 2020-08-25 | Quality Mat Company | Industrial mats having cost effective core structures |
| US9915036B2 (en) | 2014-09-23 | 2018-03-13 | Quality Mat Company | Stackable mat construction |
| JP7186693B2 (en) * | 2016-09-16 | 2022-12-09 | ダウ グローバル テクノロジーズ エルエルシー | Adhesion promoter coated particles for polymer concrete compositions |
| US10273638B1 (en) | 2018-03-26 | 2019-04-30 | Quality Mat Company | Laminated mats with closed and strengthened core layer |
| CN109056447B (en) * | 2018-09-13 | 2021-05-25 | 中交第一公路勘察设计研究院有限公司 | Self-icebreaking pavement paving layer material and construction method thereof |
| GB201821185D0 (en) * | 2018-12-24 | 2019-02-06 | Potter Roy | Aggregate compositions |
| CN113185188A (en) * | 2021-04-23 | 2021-07-30 | 广东万合新材料科技有限公司 | Material for sports ground foundation |
| CN113338107B (en) * | 2021-06-28 | 2022-02-25 | 交通运输部公路科学研究所 | Enhanced composite functional pavement structure and laying method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1531713A (en) * | 1967-05-26 | 1968-07-05 | P B U Progil Bayer Ugine | New polyurethane-based coatings |
| DE1658448A1 (en) * | 1967-06-02 | 1971-12-16 | Deutsch Amerikanische Asphalt | Road or floor covering |
| DE2821001A1 (en) * | 1978-05-12 | 1979-11-15 | Bayer Ag | METHOD FOR MANUFACTURING LAMINATE |
| JPS5854106B2 (en) * | 1979-08-31 | 1983-12-02 | カネボウエヌエスシ−株式会社 | Paving material composition |
| DE3735305A1 (en) * | 1987-10-17 | 1989-04-27 | Voigt Soehne Fa C | PROCESS FOR THE PRODUCTION OF A BELAG AND ITS USE |
| JP2869459B2 (en) * | 1991-03-29 | 1999-03-10 | 財団法人土木研究センター | Elastic pavement |
-
1995
- 1995-03-17 WO PCT/GB1995/000581 patent/WO1995025076A1/en not_active Application Discontinuation
- 1995-03-17 AU AU20764/95A patent/AU2076495A/en not_active Abandoned
- 1995-03-17 CA CA 2185676 patent/CA2185676A1/en not_active Abandoned
- 1995-03-17 EP EP19950913219 patent/EP0750595A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0750595A1 (en) | 1997-01-02 |
| AU2076495A (en) | 1995-10-03 |
| WO1995025076A1 (en) | 1995-09-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2185676A1 (en) | Road surfacing composition and process | |
| US3272098A (en) | Paving material and paving surfacing | |
| US4113401A (en) | Method of pavement repair | |
| US5367007A (en) | Multi-layer composite block & process for manufacturing | |
| CN1549882A (en) | Method of upgrading gravel and/or dirt roads and a composite road resulting therefrom | |
| JPH01174703A (en) | Wear-resistant pavement structure | |
| EP1694921A1 (en) | Method for reconstructing a bituminous-surfaced pavement | |
| US20020001506A1 (en) | Method of resurfacing roads and bridge decks | |
| US3797951A (en) | Wearing courses of stone and mastic on pavements | |
| JP3324089B2 (en) | Sand cushion material and joint material for paving stones and construction method of paving stones using the same | |
| US7312262B2 (en) | Methods and compositions for microsurfacing | |
| EP1326920A1 (en) | Paving and sealing composition and method of use | |
| US20060009551A1 (en) | Asphalt-rubber material for pedestrian and bicycle trails | |
| JPH0827707A (en) | Elastic paving material and elastic paving method | |
| JPS61233102A (en) | Construction of bitumenous paving body | |
| Chauhan et al. | Influence of Zycotherm on Properties of Bituminous Concrete Mix | |
| CA2236499A1 (en) | Water-permeable, frost-resistant resurfacing composition | |
| JPS58122960A (en) | Bituminous mixture for curable paving material | |
| JPH111903A (en) | Water permeable elastic paving material and water permeable elastic paving method | |
| JP2002356803A (en) | Paving stone sand cushion material, joint filler and execution method of paving stone making use thereof | |
| JPH11310445A (en) | Material for water-permeable elastic paving, water-permeable elastic pavement, and laying slab for water-permeable elastic paving | |
| JPS625041Y2 (en) | ||
| JPH086805Y2 (en) | Pavement structure around the bridge joint | |
| JPH11107205A (en) | Woody paving composite material and execution and woody pavement by use thereof | |
| KR950008588B1 (en) | Process for producing collar asphalt |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |