GB2277736A - Sprayable mortars - Google Patents
Sprayable mortars Download PDFInfo
- Publication number
- GB2277736A GB2277736A GB9408568A GB9408568A GB2277736A GB 2277736 A GB2277736 A GB 2277736A GB 9408568 A GB9408568 A GB 9408568A GB 9408568 A GB9408568 A GB 9408568A GB 2277736 A GB2277736 A GB 2277736A
- Authority
- GB
- United Kingdom
- Prior art keywords
- aggregate
- mortar composition
- modulus
- mortar
- elasticity
- 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.)
- Granted
Links
- 239000004570 mortar (masonry) Substances 0.000 title claims abstract description 27
- 239000000428 dust Substances 0.000 claims abstract description 19
- 239000004576 sand Substances 0.000 claims abstract description 12
- 239000011435 rock Substances 0.000 claims abstract description 11
- 239000004568 cement Substances 0.000 claims abstract description 10
- 235000019738 Limestone Nutrition 0.000 claims abstract description 8
- 239000006028 limestone Substances 0.000 claims abstract description 8
- 230000003068 static effect Effects 0.000 claims abstract description 4
- 239000000203 mixture Substances 0.000 claims description 33
- 239000000463 material Substances 0.000 claims description 10
- 238000005507 spraying Methods 0.000 claims description 8
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 239000011707 mineral Substances 0.000 claims description 5
- 239000004567 concrete Substances 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims 1
- 239000011241 protective layer Substances 0.000 abstract description 3
- 239000011150 reinforced concrete Substances 0.000 abstract description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 238000012360 testing method Methods 0.000 description 8
- 239000000470 constituent Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000010410 layer Substances 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 3
- 229910021487 silica fume Inorganic materials 0.000 description 3
- 239000002657 fibrous material Substances 0.000 description 2
- 239000010881 fly ash Substances 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 239000011398 Portland cement Substances 0.000 description 1
- 241001147388 Uncia Species 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012956 testing procedure Methods 0.000 description 1
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
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/38—Fibrous materials; Whiskers
-
- 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
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
-
- 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
- C04B2111/00034—Physico-chemical characteristics of the mixtures
- C04B2111/00146—Sprayable or pumpable mixtures
-
- 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
- C04B2111/00663—Uses not provided for elsewhere in C04B2111/00 as filling material for cavities or the like
-
- 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
- C04B2111/50—Flexible or elastic materials
Abstract
A sprayable mortar for repairing reinforced concrete comprises cement and an aggregate with an average static modulus of elasticity of 15,000 to 40,000 N/mm<2>. Especially good results are obtained when the aggregate comprises sand and small proportions of limestone dust, micro rock dust or micro rock dust fibres. The protective layers obtained are notable for their good flexibility.
Description
SPRAY MORTAR
The invention relates to a sprayable repair mortar composition and more particularly to such a composition for use on reinforced concrete.
When reinforced concrete is to be repaired, a layer of repair mortar, typically 30-35mm thick, is applied thereto, generally by spraying. The repair mortar should be able to withstand dimensional changes in the substrate without suffering damage for a reasonable period of time. A measure of this ability is provided by the characteristic crack length.- of the mortar.
When a prism of the mortar composition is subjected to a deflection test using a centre point loading apparatus, the prism deflects with increasing load and on the reverse face of the prism from the loaded face there is formed a region of microcracks which region is characteristic of the particular composition under test. Eventually these cracks will join to form a major crack and the prism will fail. The characteristic crack length may be calculated from a knowledge of the fracture energy of the composition (the area under the characteristic bellshaped curve of stress against deflection obtained from the abovementioned deflection test), the elasticity modulus (E-modulus) of the composition, and the ultimate centric tensile strength of the composition. The greater the characteristic crack length, the better performing the material.The best materials have high fracture energy as well as long characteristic crack length.
It has now been found that it is possible to prepare a repair mortar composition with outstanding properties as evidenced by a long characteristic crack length. The invention therefore provides a mortar composition for the repair of concrete surfaces, which comprises cement and aggregate, the aggregate having an overall average static modulus of elasticity of from 15,000-40,000 N/mm2
The static elasticity modulus (usually known as the "E-modulus") of the aggregate to be used in the compositions of this invention is unusually "soft", the figure for the aggregate in a conventional spray mortar being of the order of 25,000 to over 60,000 N/mm2. The E modulus is commonly measured by means of an ultrasonic testing apparatus; a typical example of such an apparatus is the Steinkamp Type BP 5 ultrasonic tester (ex Dr.-Ing. G.
Steinkamp, Bremen Germany). The E-modulus is the average E-modulus of the aggregate; it is permissible to have an aggregate component with an E-modulus in excess of the upper limit of 40,000 N/mm2, provided that the aggregate comprises sufficient aggregate of a lower
E-modulus to bring the average within the range mentioned hereinabove.
Depending on the field of application, all known types of cement may be used in the usual quantities, Portland cement being preferred.
The "soft" E-modulus range of the aggregate may be attained by the choice of aggregate employed and by its use in conjunction with natural mineral materials having a fibrous structure. The aggregate used is preferably sand in which the proportion of sand having a high
E-modulus is small. In practice, sand types having a grain size of 4 mm maximum are selected. The sand mixture employed should preferably have an average modulus of elasticity of 20,000-30,000 N/mm2 and in particular should be below 25,000 N/mm2. Typically suitable natural fibrous mineral materials are limestone dust (which may be coarse-grained), micro rock dust, micro rock dust fibres or similar fibrous materials.Such materials are preferably present in the compositions of the invention in amounts of 0.5 to 2.5% by weight of the total weight of the dry mortar composition.
The mortar composition of this invention is preferably applied to a substrate by spraying, preferably by the dry spraying process.
When sprayed as a repair mortar on to a substrate, the mortar composition according to the invention hardens to give a layer with a high fracture energy and long characteristic crack length, and this manifests itself in high flexibility, high frost resistance and a low modulus of elasticity. In contrast to conventional products which produce hardened protective layers with a modulus of elasticity of over 30,000 N/mm2, the compositions according to the invention may be used to obtain protective layers with a modulus of elasticity of below 25,000 N/mm2. Thus, the compositions according to the invention may be employed whenever it is desired to produce a malleable top layer which is insensitive towards cracks. The improved ductility and the low modulus of elasticity of the mortar compositions allows the reduction and even complete elimination of shrinkage reinforcement.Thus, layers need not be so thick and single-layer application may often be employed.
It has been found that the combination of the fibrous materials limestone dust and micro rock dust fibres with sand as hereinabove described and cement gives particularly good results, outstanding in the case of the crack test hereinabove described. Especially good combinations are those in which the weight percentages of limestone dust and micro rock dust fibres are 1.5 and 0.8-1.5 respectively. If no other components are present, the sand comprises from 7778% and cement comprises the remainder. If other components are desired, some adjustments to the sand and cement quantities are necessary, but such are well within the skill of the art.
Other components suitable for use in sprayable mortar compositions according to the invention are well known to the art. These constituents may be added in the usual proportions, depending on the field of use. For example, it is possible to add silica fume or fly ash as a filler, or known fibre reinforcement. All constituents are mixed in the dry state by known processes, and fed pneumatically to the spray nozzle of any dry spraying machine (e.g. MEYCO Piccola, MEYCO Unica ex Meynadier AG., Winterthur, Switzerland), where they are mixed with water and sprayed. The quantity of water may vary depending on conditions, but may readily be determined in any situation by the skilled worker.Typical water/binder weight ratios (where binder naturally includes such materials as silica fume or fly ash, where these are present) for a dry spraying operation are from 0.3-0.6, preferably from 0.4-0.5. An accelerator is normally not used. The application depth may vary from 12 to 100 mm.
The invention is further described with reference to the following non-limiting examples in which all parts are by weight.
Example 1
Constituents modulus of density proportions
elasticity N/mm2 kg/m3 % by weight cement 18,000 (17,000-21,000) 2000-2150 20.0 sands 24,000 (23,000-83,000) 2670-3050 77.7 limestone dust 24,000 2500 1.5 micro rock dust 17,000 (crosswise) 2500 0.8 fibres 170,000 (lengthwise) sprayable mortar 22,137 2131 100
The various constituents are mixed in the dry state and water is added at the spray nozzle in such a rate as to give a ratio of water/binding agent of 0.4. This ratio is used in the subsequent examples.
Examples 2 to 12
Further examples of appropriate sprayable mortar mixes are given in the table, where the proportions of the various constituents are given in percentages by weight. In the table, "MSM" is micro rock dust, "MSM PF" is micro rock dust fibres and "KTSM" is limestone dust . The limestone dust is coarse grain (4 mm) material.
Table
Example cement sands KSTM MSM MSM PF 2 20 77.7 1.5 0.8 3 20 75.5 3 1.5 4 20 72 5 3 5 15 74.5 10 0.5 6 15 75 10 7 20 77.7 1.5 0.8 8 20 77 2.5 0.5 9 20 69.2 10 0.8 10 20 77 1.5 1.5 11 20 77 3 12 20 77 3 Example 13
The compositions of Examples 1 and 10 are subjected to testing according to the test method RILEM 50-FMC draft recommendation. A commercially-available repair mortar comprising by weight 42% cement, 33% sand (0.15-1.20mm), 17% sand (1.20-2.38mm), 3.4% silica fume, 3.3% calcium oxide, and the remainder miscellaneous minor quantities of admixtures is subjected to the same testing procedure. From the testing, the characteristic crack lengths are determined. The results are as follows:
Example 1 435mm
Example 10 382mm
Commercial composition 262mm
The crack performances of the compositions according to the invention are considerably superior to that of the commercially-available composition.
The compositions are sprayed on to a concrete substrate. In subsequent flexibility testing, the compositions according to the invention prove to be superior to the commercial composition in terms of flexibility and durability.
Claims (7)
1. A mortar composition for the repair of concrete surfaces, which comprises cement and
aggregate, the aggregate having an overall average static modulus of elasticity of from
15,000-40,000 N/mm2
2. A mortar composition according to claim 1, wherein the aggregate is a combination of
sand and natural mineral material having a fibrous structure.
3. A mortar composition according to claim 1 or claim 2, wherein the natural mineral
material is selected from at least one of limestone dust, micro rock dust and micro rock
dust fibres.
4. A mortar composition according to claim 3, wherein the natural mineral material
comprises from 0.5 to 2.5% by weight of the total weight of the dry mortar composition.
5. A mortar composition according to claim 2, wherein the sand has an average modulus
of elasticity of 20,000-30,000 N/mm2 and a maximum particle size of 4mm.
6. A process of repairing a concrete surface, comprising the spraying thereon of a mortar
composition according to claim 1.
7. A process according to claim 6, wherein the spraying is carried out by the dry spraying
process.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4314612 | 1993-05-04 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9408568D0 GB9408568D0 (en) | 1994-06-22 |
| GB2277736A true GB2277736A (en) | 1994-11-09 |
| GB2277736B GB2277736B (en) | 1996-09-25 |
Family
ID=6487073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9408568A Expired - Fee Related GB2277736B (en) | 1993-05-04 | 1994-04-29 | Spray mortar |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPH06345509A (en) |
| CA (1) | CA2122647A1 (en) |
| CH (1) | CH688411A5 (en) |
| DE (1) | DE4415558A1 (en) |
| FR (1) | FR2704854B1 (en) |
| GB (1) | GB2277736B (en) |
| IT (1) | IT1272236B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2192464A1 (en) * | 2001-11-16 | 2003-10-01 | Los Santos Parejo Diego De | Mortar based on cement and sand comprises mix including calcarenite and medium and coarse sands |
| ES2211319A1 (en) * | 2002-05-23 | 2004-07-01 | Eduardo Ramirez de Arellano | Concentrated one-coat mortar, method for making the same, and method for applying the same |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29613699U1 (en) * | 1996-04-18 | 1996-10-31 | Kschiwan Joerg | Wall coating |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1144024A (en) * | 1965-03-25 | 1969-03-05 | Gullhoegens Bruk Ab | Binding agent for plaster and/or mortar, and mortar mixtures produced therefrom |
| GB1325518A (en) * | 1971-01-20 | 1973-08-01 | Ardex Chemie Gmbh | Mortar mix for the production of composition floors or floor surfaces |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0517196A (en) * | 1991-07-11 | 1993-01-26 | Nippon Cement Co Ltd | Grouting material for repairing concrete structure |
| JP3002759B2 (en) * | 1991-09-06 | 2000-01-24 | 住友大阪セメント株式会社 | Repair cement-based injection material composition |
| ZW19392A1 (en) * | 1991-12-20 | 1993-04-14 | Csir | Pumpable grout |
-
1994
- 1994-04-28 JP JP6091347A patent/JPH06345509A/en active Pending
- 1994-04-29 GB GB9408568A patent/GB2277736B/en not_active Expired - Fee Related
- 1994-04-29 CH CH01337/94A patent/CH688411A5/en not_active IP Right Cessation
- 1994-05-02 FR FR9405507A patent/FR2704854B1/en not_active Expired - Fee Related
- 1994-05-02 CA CA002122647A patent/CA2122647A1/en not_active Abandoned
- 1994-05-03 IT ITRM940273A patent/IT1272236B/en active IP Right Grant
- 1994-05-03 DE DE4415558A patent/DE4415558A1/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1144024A (en) * | 1965-03-25 | 1969-03-05 | Gullhoegens Bruk Ab | Binding agent for plaster and/or mortar, and mortar mixtures produced therefrom |
| GB1145239A (en) * | 1965-03-25 | 1969-03-12 | Gullhoegens Bruk Ab | Binding agent for plaster and/or mortar, and mortar mixtures produced therefrom |
| GB1325518A (en) * | 1971-01-20 | 1973-08-01 | Ardex Chemie Gmbh | Mortar mix for the production of composition floors or floor surfaces |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2192464A1 (en) * | 2001-11-16 | 2003-10-01 | Los Santos Parejo Diego De | Mortar based on cement and sand comprises mix including calcarenite and medium and coarse sands |
| ES2211319A1 (en) * | 2002-05-23 | 2004-07-01 | Eduardo Ramirez de Arellano | Concentrated one-coat mortar, method for making the same, and method for applying the same |
Also Published As
| Publication number | Publication date |
|---|---|
| ITRM940273A1 (en) | 1995-11-03 |
| GB2277736B (en) | 1996-09-25 |
| CA2122647A1 (en) | 1994-11-05 |
| GB9408568D0 (en) | 1994-06-22 |
| JPH06345509A (en) | 1994-12-20 |
| DE4415558A1 (en) | 1994-11-10 |
| ITRM940273A0 (en) | 1994-05-03 |
| IT1272236B (en) | 1997-06-16 |
| FR2704854A1 (en) | 1994-11-10 |
| CH688411A5 (en) | 1997-09-15 |
| FR2704854B1 (en) | 1998-12-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhou et al. | Improved fiber distribution and mechanical properties of engineered cementitious composites by adjusting the mixing sequence | |
| US10259747B2 (en) | Advanced fiber reinforced concrete mix designs and admixtures systems | |
| US7241338B2 (en) | Sprayable, strain-hardening cementitious compositions | |
| JP4709677B2 (en) | Premix high toughness polymer cement mortar material and high toughness polymer cement mortar | |
| Ganesan et al. | Effect of hybrid fibers on tension stiffening of reinforced geopolymer concrete | |
| Abd et al. | The Effect of Low Velocity Impact Loading on Self-Compacting Concrete Reinforced with Carbon Fiber Reinforced Polymers | |
| GB2277736A (en) | Sprayable mortars | |
| Jhatial et al. | Influence of long polypropylene fibre on the properties of concrete | |
| Ali et al. | Flexural behaviour of reinforced concrete beams repaired with styrene—butadiene rubber latex, silica fume and methylcellulose repair formulations | |
| Kenai et al. | Performance of repair mortar with natural fibers | |
| Chachar et al. | Workability and Flexural Strength of Recycled Aggregate Concrete with Steel Fibers | |
| US8697780B2 (en) | High strength concrete made with PVA reinforcement fibers and its associated method of manufacture | |
| Ezeldin et al. | Toughness behavior of fiber-reinforced rapid-set materials: a preliminary study | |
| JP2010105831A (en) | Polymer cement composition | |
| Adam et al. | Influence of coarse aggregate on the shrinkage of normal and high-strength concretes | |
| JPH02275739A (en) | Floor coating material and its production | |
| JPH07315901A (en) | Mortar composition for repairs capable of spraying | |
| Agopyan et al. | Building panels made with natural fibre reinforced alternative cements | |
| Haddadou et al. | The effect of steel fiber size on the properties of fresh and hardened self-compacting concrete incorporating marble powder | |
| Stojanović et al. | Influence of different types of fibers on the ultimate and residual flexural strength of sprayed concrete | |
| Keerthana et al. | Experimental studies on the behavior of the fiber reinforced concrete blended with admixtures | |
| Thanga et al. | The influence of PVA content on the flexural behavior of engineered cementitious composite using local materials | |
| Gyawali | Effect of sand types and mixing procedures on the flexural behaviour of the high ductile mortar in monotonic and cyclic loadings | |
| Ramasamy | Effect of Pozzolanas on Fibre Reinforced Concrete. | |
| Gökçe | Using the Plate-Creep test to determine the impact strength properties of concrete |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19990429 |