AU748229B2 - Waterproofing additive for cement and concrete comprising modified pozzolanic materials - Google Patents
Waterproofing additive for cement and concrete comprising modified pozzolanic materials Download PDFInfo
- Publication number
- AU748229B2 AU748229B2 AU58934/98A AU5893498A AU748229B2 AU 748229 B2 AU748229 B2 AU 748229B2 AU 58934/98 A AU58934/98 A AU 58934/98A AU 5893498 A AU5893498 A AU 5893498A AU 748229 B2 AU748229 B2 AU 748229B2
- Authority
- AU
- Australia
- Prior art keywords
- concrete
- waterproofing additive
- cement
- waterproofing
- additive
- 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.)
- Ceased
Links
- 239000004567 concrete Substances 0.000 title claims description 77
- 239000000463 material Substances 0.000 title claims description 62
- 238000004078 waterproofing Methods 0.000 title claims description 51
- 239000000654 additive Substances 0.000 title claims description 48
- 230000000996 additive effect Effects 0.000 title claims description 40
- 239000004568 cement Substances 0.000 title claims description 28
- 229910021487 silica fume Inorganic materials 0.000 claims description 54
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 54
- 230000002209 hydrophobic effect Effects 0.000 claims description 47
- 238000010521 absorption reaction Methods 0.000 claims description 21
- 239000011083 cement mortar Substances 0.000 claims description 19
- 239000000839 emulsion Substances 0.000 claims description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 18
- 239000002253 acid Substances 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 11
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 claims description 9
- QMMJWQMCMRUYTG-UHFFFAOYSA-N 1,2,4,5-tetrachloro-3-(trifluoromethyl)benzene Chemical compound FC(F)(F)C1=C(Cl)C(Cl)=CC(Cl)=C1Cl QMMJWQMCMRUYTG-UHFFFAOYSA-N 0.000 claims description 8
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 238000005507 spraying Methods 0.000 claims description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 6
- 239000004576 sand Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 239000000344 soap Substances 0.000 claims description 6
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 claims description 5
- 235000013539 calcium stearate Nutrition 0.000 claims description 5
- 239000008116 calcium stearate Substances 0.000 claims description 5
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 claims description 4
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 claims description 4
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 claims description 4
- 239000005642 Oleic acid Substances 0.000 claims description 4
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 claims description 4
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 claims description 4
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 claims description 4
- 150000002148 esters Chemical class 0.000 claims 1
- 239000000203 mixture Substances 0.000 description 28
- 150000001875 compounds Chemical class 0.000 description 20
- 238000012360 testing method Methods 0.000 description 16
- 230000035515 penetration Effects 0.000 description 9
- 239000001993 wax Substances 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 6
- 239000011148 porous material Substances 0.000 description 6
- 239000000470 constituent Substances 0.000 description 5
- 230000035699 permeability Effects 0.000 description 5
- 238000007792 addition Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- RQFLGKYCYMMRMC-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O.CCCCCCCCCCCCCCCCCC(O)=O RQFLGKYCYMMRMC-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000008030 superplasticizer Substances 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000003377 silicon compounds Chemical class 0.000 description 3
- 230000004584 weight gain Effects 0.000 description 3
- 235000019786 weight gain Nutrition 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000004815 dispersion polymer Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001804 emulsifying effect Effects 0.000 description 2
- HQKMJHAJHXVSDF-UHFFFAOYSA-L magnesium stearate Chemical compound [Mg+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O HQKMJHAJHXVSDF-UHFFFAOYSA-L 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- 150000002902 organometallic compounds Chemical class 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 239000002352 surface water Substances 0.000 description 2
- 229920001059 synthetic polymer Polymers 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- NYZBMVSQWXDALK-UHFFFAOYSA-N CCCC[Ca] Chemical compound CCCC[Ca] NYZBMVSQWXDALK-UHFFFAOYSA-N 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- 239000004610 Internal Lubricant Substances 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000005791 algae growth Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- CEGOLXSVJUTHNZ-UHFFFAOYSA-K aluminium tristearate Chemical compound [Al+3].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CEGOLXSVJUTHNZ-UHFFFAOYSA-K 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013068 control sample Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 238000006253 efflorescence Methods 0.000 description 1
- 239000003995 emulsifying agent Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- -1 fatty acid ester Chemical class 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 235000019359 magnesium stearate Nutrition 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 206010037844 rash Diseases 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000010959 steel Substances 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
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/14—Waste materials; Refuse from metallurgical processes
- C04B18/146—Silica fume
-
- 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
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/0028—Aspects relating to the mixing step of the mortar preparation
- C04B40/0039—Premixtures of ingredients
-
- 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
- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/60—Agents for protection against chemical, physical or biological attack
- C04B2103/65—Water proofers or repellants
-
- 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
Description
WO 99/28264 PCT/SG97/00064 WATERPROOFING ADDITIVE FOR CEMENT AND CONCRETE COMPRISING MODIFIED POZZOLANIC MATERIALS Waterproofing is one of the most critical issues for the durability of concrete. The majority of concrete failures are attributed to the high permeability and sorptivity of concrete against water penetration and the ingress of chloride or sulfate ions dissolved in the water, causing not only water leakage but also the corrosion of steel rebars and destructive expansion of the concrete.
Silica fume, a by-product from the production of silicon or ferro-silicon alloys, is commonly used as a cement and concrete additive to produce corrosion-resistant concrete, concrete having improved mechanical properties or water-tight concrete (see, for example, US 4,118,242, US 4,310,486 and US 5,472,501). However, its disadvantages are poor workability and relatively high surface water absorption due to the capillary action of fine capillary pores which result in high sorptivity of the concrete and therefore potential high chloride/sulfate build up at the splash and tidal zones of marine concrete structures. Furthermore, the high water absorption will result in a concrete which is water-tight but not damp-proof and will fail to meet the commonly used project specification of a water absorption of less than 1% of the concrete when it is tested in accordance with BS1881 Part 122.
Hydrophobic compounds, such as calcium stearate, silicon, wax or bitumen emulsion are also commonly used as waterproofing admixtures of concrete, to impart a hydrophobic coating to the capillary surfaces as well as blocking some pores.
However such compounds have the disadvantages of reduced compressive strength (typically 10-15% lower than the plain concrete) and reduced effectiveness under high hydrostatic head.
Therefore, for a durable waterproofing concrete both low permeability and low absorption to water are sought. One solution is to make separate additions of silica fume and hydrophobic compound during the production of the concrete. However, this requires additional mixingldispersing and the hydrophobic compound is usually SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -2added as an emulsion in order to achieve a homogeneous mix. The pre-emulsifying of the hydrophobic compound and the complicated dosing procedure make such a procedure impractical and uneconomical for use on construction sites. It should also be noted that the emulsion can only have limited use in cold environments because it is generally not frost resistant. Furthermore, the emulsifier may reduce the hydrophobic action and cause excessive air entrainment and loss of strength.
Another approach is disclosed in US 4,762,867. This describes the use of an amphiphilic synthetic polymer dispersion to reduce water absorption in cement mortar and concrete. Synthetic polymer dispersion is very expensive and has an adverse effect on the compressive strength of the concrete. It is not practical and has only limited usage. It is therefore not generally used by the construction industry for large scale waterproofing concrete production.
According to the present invention from one aspect there is provided a waterproofing additive for cement and/or concrete, comprising at least one pozzolanic material modified with at least one hydrophobic material.
The pozzolanic material preferably comprises one or more pozzolanic components.
The pozzolanic material preferably comprises one or more of silica fume, microsilica and metakaolin. The silica fume may be densified or undensified silica fume. The microsilica is preferably refined natural microsilica and is preferably amorphous. One particularly preferred composition for the pozzolanic material is a mixture of silica fume and microsilica, most preferably in approximately equal amounts by weight.
The hydrophobic material is suitably a hydrophobic compound, preferably an organic or organometallic compound, most preferably of a long chain paraffinic acid. The hydrophobic material may be a paraffinic or fatty acid ester, e.g. butyl stearate. The hydrophobic compound may be a soap, especially a metallic soap of a paraffinic acid, e.g. calcium stearate, magnesium stearate or aluminium stearate, or an organic soap of a paraffinic acid, e.g. an ammonium salt. The hydrophobic compound may be oleic acid, a wax emulsion, siloxane or a silicon emulsion.
SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -3- The or each pozzolanic constituent of the additive may be modified with one or more hydrophobic materials. Preferred waterproofing additives are mixtures of at least one pozzolanic material silica fume, microsilica or metakaolin) with at least one hydrophobic compound, or possibly two or more hydrophobic compounds of different types. The combination of such materials has been observed to enable better mixing and a freer flowing powder nature of the finished product, as well as increased shelf life thereof.
The pozzolanic material is preferably modified by spraying and/or blending with the hydrophobic material, suitably in a high speed/shear mixer. The mixing operation preferably results in an intimate, and preferably substantially fully mixed, mixture of the pozzolanic material and the hydrophobic material(s).
The total weight of the hydrophobic material(s) in the waterproofing additive is suitably in the range from 5 to 30% of the weight of the pozzolanic material, preferably 5 to 15% and most preferably around A particularly preferred composition is an approximately 1:1 mixture (by weight) of densified silica fume and microsilica modified with approximately 10% (by weight of the combined pozzolanic constituents) of butyl stearate. Another particularly preferred composition is metakaolin modified with approximately 10% (by weight) of butyl stearate.
According to a second aspect of the present invention there is provided a cement mortar or concrete comprising a waterproofing additive according to the first aspect of the invention. The cement mortar or concrete preferably comprises an amount of the waterproofing additive such that the pozzolanic material of the additive is present in the cement mortar or concrete in an amount in the range from 5 to 15% of the weight of cement, and most preferably from around 8 to 10%. The cement mortar or concrete preferably has improved water impermeability (suitably less than 10 mm after 28 days when measured in accordance with DIN 1048) and/or reduced water absorption (suitably less than 1% when measured in accordance with BS1881 Part 122), preferably whilst retaining acceptable compressive strength. Thus, the SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -4waterproofing additive is preferably capable of acting to improve the waterproofing of cement mortar and/or concrete.
According to a third aspect of the present invention there is provided a method of preparing a waterproofing additive for cement and/or concrete, comprising modifying a pozzolanic material by spraying and/or blending with a hydrophobic material. The step of spraying and/or blending is performed using a high speed/shear mixer.
According to a fourth aspect of the present invention there is provided a method of preparing cement mortar or concrete comprising mixing cement, sand and water with a waterproofing additive according to the first aspect of the invention and/or manufactured in accordance with the third aspect of the invention.
In ASTM C618, a pozzolan is defined as a siliceous and aluminous material which, in itself, possesses little or no cementitious value but which will, in finely divided form in the presence of moisture, react chemically with calcium hydroxide at ordinary temperature to form compounds possessing cementitious properties.
The present invention will now be described by way of example only, with reference to the following embodiments which are illustrative and not limiting.
EXAMPLE 1 Waterproofing for Cement Mortars The mixture proportions of the cement mortars in this example are based on the following composition: cement (OPC): water: sand: waterproofing additive: liquid superplasticizer in the ratio of 1 0.38 2.61 0-0.08 0.01-0.02 (by weight) respectively. The waterproofing additive comprises a pozzolanic material silica fume, refined natural microsilica or metakaolin) modified with a hydrophobic material an organic or organometallic compound such as butyl stearate, calcium stearate, another metallic soap of a paraffinic acid, oleic acid, wax emulsion, siloxane or a silicon emulsion). Thus, in the waterproofing additive the hydrophobic compound(s) are provided integrally with the pozzolanic material.
SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 The silica fume that was used was a commercially available product having a typical composition as shown in table 1 (with constituents indicated by weight in Table 1: Typical Composition of Silica Fume Composition SiO 2 S03 C Fe 2 0 3 CaO MgO Na20 K 2 0 Usual range 85-95 0.1-0.5 1.0-6.0 0.1-0.4 0.1-0.5 0.1-1.0 0.1-1.0 0.1-1.0 Tvical 90-94 1 0 max 3.0 max 0.3 0.3 0.4 1.0 max 1.0 max Both densified silica fume (as supplied by Scancem Materials Pty Ltd, Australia) and undensified silica fume (as supplied by Elkem Materials, Norway) are suitable. The typical density range for the densified silica fume is 500-650 kg/m 3 and for undensified silica fume is 250-400 kg/m 3 The microsilica that was used was a refined natural amorphous silica (as supplied by Microsilica New Zealand Limited, New Zealand). The typical composition is given in table 2 (with constituents indicated by weight in Table 2: Typical Composition of Refined Natural Microsilica Composition SiO 2 SO3 CI LOI Alkali content Bulk Density Typical 90.8 0.15 0.001 2.2 0.012 700kg/m 3 The metakaolin that was used was a commercially available product produced by high temperature treatment of kaolin (as supplied by ECC International, UK or Engelhard Corporation, USA). The typical composition is given in table 3 (with constituents indicated by weight in Table 3: Typical Composition of Metakaolin Composition SiO 2 A1 2 0 3 Fe20 3 CaO MgO K 2 0 Na 2 0 Typical 52-55 40-42 0.6-4.6 0-0.1 0.2-0.4 0.6-2.4 <0.1 The selected pozzolanic materials were processed by spraying and blending with one SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -6or more hydrophobic compounds in a high speed, high shear mixer to produce a surface modified waterproofing additive for cement and concrete. The preferred hydrophobic compounds are butyl stearate, calcium stearate or other metallic soaps of paraffinic acids which are commonly used as waterproofing additives in the cement and concrete. Other suitable hydrophobic compounds include oleic acid, wax emulsion, siloxane and silicon emulsions, but with reduced effectiveness.
Cement mortar mixtures in which a range of hydrophobically modified pozzolanic materials with cement, sand, water and superplasticizer were prepared in a Hobart mixer. The liquid superplasticizer was added to adjust the mix to a constant workability (flow). The mortars' compressive strengths were tested according to ASTM C109 and the water absorption was tested by a modified method according to BS 1881 Part 122 at 7 days. The results (including results for a control sample with none of the hydrophobic material) are summarized for each of the chosen pozzolanic materials in tables 4, 5, 6 and 7.
SUBSTITUTE SHEET (RULE 26) WO 99/28264 WO 9928264PCT/SG97/00064 -7- Table 4: Test Results of Cement Mortar With Modified Densified Silica Fume Hydrophobic Butyl Calcium Oleic Wa x Compound None Stearate Stearate Acid Emulsion Siloxane Emuls ion Compressive Strength (MPa) 1 day 7 days 28 days Water absorption @7 days
N%
36.0 63.5 68.5 35.0 63.0 70.5 31.0 54.0 61.5 0.68 24.0 52.0 70.0 24.5 49.0 64.5 17.5 52.5 71.0 1.55 46.0 74.0 2.09 2.20 0.58 1.94 1.56 Table 5: Test Results of Cement Mortar with Modified Undensified Silica Fume Hydrophobic Butyl Calcium Olelc Wax Silicon Compound None Stearate Stearate Acid Emulsion Siloxane Emulsion Compressive Strength (MPa) I day 7 days 28 days Water absorption 7 days
M%
36.0 63.5 68.5 34.5 68.5 72.0 31.0 60.0 66.0 30.0 66.5 70.0 35.0 66.0 '69.5 7.0 62.0 75.0 1.43 66.0 74.0 1.69 2.20 0.65 0.80 1.41 1.46 SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -8- Table 6: Test Results of Cement Mortar with Modified Microsilica Hydrophobic Butyl Calcium Oleic Wax Silicon Compound None Stearate Stearate Acid Emulsion Siloxane Emulsion Compressive Strength (MPa) 1 day 7 days 28 days Water absorption 7 days 38.0 66.5 76.0 36.0 63.0 78.0 35.5 59.5 73.0 0.79 29.5 54.5 79.0 33.0 62.0 71.0 1.5 43.5 73.5 1.43 12.0 54.0 76.5 2.04 2.12 0.63 1.61 1.70 Table 7: Test Results of Cement Mortar with Modified Metakaolin Hydrophobic Butyl Calcium Oleic Wax Silicon Compound None Stearate Stearate Acid Emulsion Siloxane Emulsion Compressive Strength (MPa) 1 day 7 days 28 days Water absorption 7 days 33.0 62.5 65.0 32.0 63.0 67.5 30.5 64.0 64.0 0.63 33.0 65.0 71.0 33.0 64.0 68.0 1.0 60.5 71.0 1.53 56.0 72.0 1.66 2.30 0.58 1.29 1.42 The above study shows that the waterproofing additive can effectively reduce the water absorption of the cement while generally no or little adverse effect on the 28 days compressive strength was observed. In fact, in many cases increased compressive strength was observed. The fluctuation in the strength data of the plain SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -9mortars was due to the different sources of cement available at the different times of testing. Therefore comparison should be restricted to within each group of tests.
Pozzolans modified with butyl stearate showed the best combined performance in term of strength development and water absorption.
Similar mortars could be prepared using a mixture of more than one waterproofing additive. More than one pozzolanic material could be used, and the or each pozzolanic material could be modified with the same or different hydrophobic materials or with more than one hydrophobic material.
EXAMPLE 2 Waterproofing for Concrete The effectiveness of the waterproofing additive on concrete is demonstrated by the following study.
The modified pozzolanic material employed in this study was densified silica fume (as described in detail in relation to example 1) modified with 10% butyl stearate. Other pozzolanic materials modified with butyl stearate are expected to perform similar or better as shown in the cement mortar studies. Two typical water to cement (w/c) ratios of 0.36 and 0.45 were used in this study and the dosage levels of the modified silica fume (MSF) were at 5% and 10% by weight of the total binder (cement silica fume) content. The concrete mixture proportions and the test results are shown in tables 8 and 9, one table for each of the water: cement ratios.
The concretes were prepared in a concrete drum mixer. The cement (OPC), densified silica fume and the liquid superplasticizer (high range water reducing agent: HRWRA) were commercially available materials. The fresh properties and strength of the concrete were tested according to the guidelines set in BS 1881. The water absorption was tested at 7 and 28 days in accordance with BS 1881 Part 122. The water penetration was tested at 28 days according to DIN 1048 and the rapid chloride penetration test was carried out at 28 days according to ASTM 1202.
SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 Table 8: Test Results of Concrete (water: cement=0.36) Materials Plain MSF-1 MSF-2 (no MSF) at 5% at Mixture Proportion--- OPC (kg) 420 399 378 Sand (kg) 786 786 786 Stone (kg) 1063 1063 1063 Water (kg) 151 151 151 Modified Silica Fume (kg) 21 42 HRWRA (U100 kg Binder) 1.2 1.3 Results Initial Slump (mm) 155 200 200 Initial Setting Time (hrs:min) 7:45 Not tested 11:00 Final Setting Time (hrs:min) 9:35 Not tested 13:15 Compressive Strength (MPa) 1 day 47.0 35.5 30.0 3 days 64.0 58.0 53.0 7 days 72.5 70.0 68.5 28 days 76.0 79.0 78.0 56 days 76.5 84.0 82.0 Water absorption 7 days 1.83 0.86 0.65 28 days 1.80 0.76 0.59 Water penetration 28 days (mm) 15.0 3.0 Rapid Chloride Penetration 28 days (Coulombs) 2889 1130 479 SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -11 Table 9: Test Results of Concrete (water: cement 0.45) Materials Plain MSF-1 (no MSF) at 5% MSF-2 at Mixture Proportion OPC (kg) Sand (kg) Stone (kg) Water (kg) Modified Silica Fume (kg) HRWRA (L/100 kg Binder) Results Initial Slump (mm) Initial Setting Time (hrs:min) Final Setting Time (hrs:mln) Compressive Strength (MPa) 1 day 3 days 7 days 28 days 56 days Water absorption 7 days 28 days Water penetration 28 days (mm) Rapid Chloride Penetration 28 days (Coulombs) 380 782 1057 171 361 782 1057 171 19 1.2 342 782 1057 171 38 1.4 130 5:30 6:45 140 5:25 7:00 32.5 49.5 57.0 65.0 65.5 31.5 47.0 57.5 68.0 70.0 105 6:00 7:25 27.0 44.0 56.5 64.5 69.5 2.28 1.02 0.78 2.20 0.99 0.70 25.0 6.0 2641 1763 712 SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -12- The results show that the compressive strength of the concrete modified with 5-10% of the particular waterproofing additive can be maintained or increased by up to 4% and 10% at 28 days and 56 days respectively. The water permeability, water absorption and chloride permeability are drastically reduced. Even at a waterlcement ratio of 0.45 and an addition of 5% modified silica fume, the water penetration was only 6 mm, which is far below the 20 mm (average) penetration as specified in ENV206 for water impermeable concrete. The water absorption can also be controlled to below 1%.
Different waterproofing additives, or mixtures of additives, as described for example 1 could be used in preparing concrete as for this example.
EXAMPLE 3 Water Sorptivity of Concrete One of the additional benefits of the novel waterproofing additives described above is the reduced water sorptivity of the modified concrete. The sorptivity test is in fact similar to the surface water absorption test. The only difference is that the specimen in this case is not fully immersed in water, instead only the bottom face of the test specimen is placed in contact with water. In this way capillary suction can be directly visually monitored by observing the height increase of the wetted areas, or by measurement of the weight gain. The following example demonstrates the sorptivity behaviour of the concrete under capillary forces.
The concrete mixture proportions used for the test were the same as given in example 2 with 10% addition of modified silica fume. Additionally, a concrete with unmodified silica fume was prepared for comparison. The concrete was cured for 28 days and core samples having dimensions of 75 mm in diameter and 75 mm in height were taken. The samples were coated with an epoxy resin over the length of the longitudinal faces and were dried in an oven at 105°C for 3 days and cooled in a desiccator for 1 day before the test. The test specimen was placed in contact with water at the bottom surface of the cylinder and the weight gain of the specimen was measured after 30 and 60 minutes and 24 hours of water contact. The specimens were split into two halves after 24 hours and the height of the wetted SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -13areas were measured. The results are shown in table Table 10: Comparison of Water Sorptivity of Plain Concrete, Silica Fume Concrete and Concrete with Modified Silica Fume Concrete Plain SF-Concrete MSF-Concrete W/C Ratio 0.36 0.45 0.36 0.45 0.36 0.45 Weight gain (g) 30 min 2.5 4.2 1.9 3.9 0.4 60 min 4.0 7.5 3.2 5.9 0.9 1.9 24 hours 13.8 22.8 10.2 17.6 3.0 5.1 Height of wetted area 24 hours (mm) 51 63 38 48 4 It is evident that the sorptivity of silica fume concrete is still very high, due to the presence of fine capillary pores. The hydrophobically modified silica fume is highly effective in reducing the capillary suction of the concrete, which is highly beneficial for a durable concrete so as to prevent rising damp and formation of efflorescence, reduce the build up of chloride and sulfate concentrations at the tidal and splash zones of marine concrete, minimize freeze-thaw damage and reduce algal growth on the concrete's surface.
In summary, the improved waterproofing additives described above have been observed to provide an improved and economical solution to produce highly durable water impermeable and damp-proof concrete which is able to overcome the disadvantages of the relatively high water absorption of waterproofed concrete containing silica fume and the reduced compressive strength, relatively high water permeability of waterproofed concrete containing hydrophobic compounds. It was found that waterproofing concrete can be produced with the addition of a modified pozzolanic composition to meet the water impermeability of concrete as specified in SUBSTITUTE SHEET (RULE 26) WO 99/28264 PCT/SG97/00064 -14- ENV 206 and the water absorption of less than 1% tested in accordance with BS1881 Part 122.
As described in the examples above, pozzolanic materials are used as carriers for the hydrophobic compounds and therefore a pre-emulsifying is not necessary, providing a substantial advantage over the prior art. The pozzolan appears to act as a reactive pore filler by reacting with the hydration products of the cement to form insoluble precipitants which reduce the porosity and the pore size of the cement paste. At the same time the absorbed hydrophobic compound is believed to migrate toward the air/water interface of the concrete and form a hydrophobic layer at the concrete surface and the walls of the capillary pores which form an effective barrier against capillary suction of water. The novel waterproofing additives described above have been found to provide a highly advantageous solution for providing concrete with both water impermeable and damp-proof characteristics. The use of such waterproofing additives is very straightforward and does not differ from the normal use of silica fume in concrete production. In fact, the workability of fresh concrete containing the said novel waterproofing additive has been found to be better than the normal silica fume concrete, as the hydrophobic compounds act as an internal lubricant for the cement particles.
The present invention may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof irrespective of whether it relates to the presently claimed invention. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.
SUBSTITUTE SHEET (RULE 26)
Claims (22)
1. A waterproofing additive for cement and/or concrete, comprising at least one pozzolanic material modified with at least one hydrophobic material.
2. A waterproofing additive as claimed in claim 1, wherein the pozzolanic material comprises one or more silica fume, microsilica and metakaolin.
3. A waterproofing additive as claimed in claim 2, wherein the pozzolanic material comprises silica fume and microsilica.
4. A waterproofing additive as claimed in claim 3, wherein the pozzolanic material comprises approximately equal amounts of silica fume and microsilica by weight.
A waterproofing additive as claimed in any one of claims 2 to 4, wherein the silica fume is densified silica fume.
6. A waterproofing additive as claimed in any one of claims 2 to 5, wherein the microsilica is refined natural microsilica.
7. A waterproofing additive as claimed in any one of claims 1 to 6, wherein the hydrophobic material is a metallic or organic soap of a paraffinic acid.
8. A waterproofing additive as claimed in claim 7, wherein the hydrophobic material is calcium stearate.
9. A waterproofing additive as claimed in any of claims 1 to 6, wherein the hydrophobic material is an ester of a paraffinic acid.
C( Melboure\004010352 Printed 7 March 2002 (14:34) 16 A waterproofing additive as claimed in any of claims 1 to 6, wherein the hydrophobic material is butyl stearate.
11. A waterproofing additive as claimed in any of claims 1 to 6, wherein the hydrophobic material is oleic acid, a wax emulsion, siloxane or a silicon emulsion.
12. A waterproofing additive as claimed in any one of claims 1 to 11, wherein the pozzolanic material is modified with at least two hydrophobic materials.
13. A waterproofing additive as claimed in any one of claims 1 to 12, wherein the pozzolanic material is modified by spraying and/or blending with the hydrophobic material(s).
14. A waterproofing additive as claimed in any one of claims 1 to 13, comprising 15 from 5 to 30% of total hydrophobic material(s) by weight of the pozzolanic material.
A waterproofing additive as claimed in claim 14, comprising about 10% of total hydrophobic material(s) by weight of the pozzolanic material.
16. A cement mortar or concrete comprising a waterproofing additive as claimed in any preceding claim.
17. A cement mortar or concrete as claimed in claim 16, comprising from 5 to 15% of the pozzolanic material by weight of cement.
18. A cement mortar or concrete as claimed in claim 16 or 17, having a water absorption in accordance with BS1881 Part 122 of less than 1%. Melboume\004010352 Printed 7 March 2002 (14:34) 17
19. A method of preparing a waterproofing additive for cement and/or concrete, comprising modifying a pozzolanic material by spraying and/or blending with a hydrophobic material.
20. A method as claimed in claim 19, wherein the step of spraying and/or blending is performed using a high speed/shear mixer.
21. A method of preparing cement mortar or concrete comprising mixing cement, sand and water with a waterproofing additive as claimed in any of claims 1 to
22. A waterproofing additive for cement and/or concrete as defined in claim 1 and substantially as hereinbefore described with reference to the Examples. o. S 15 DATED: 7 March 2002 FREEHILLS CARTER SMITH BEADLE Patent Attorneys for the Applicant: SSANGYONG CEMENT (SINGAPORE) LIMITED Melboume\004010352 Printed 7 March 2002 (14:34)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/SG1997/000064 WO1999028264A1 (en) | 1997-12-03 | 1997-12-03 | Waterproofing additive for cement and concrete comprising modified pozzolanic materials |
Publications (2)
Publication Number | Publication Date |
---|---|
AU5893498A AU5893498A (en) | 1999-06-16 |
AU748229B2 true AU748229B2 (en) | 2002-05-30 |
Family
ID=20429577
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU58934/98A Ceased AU748229B2 (en) | 1997-12-03 | 1997-12-03 | Waterproofing additive for cement and concrete comprising modified pozzolanic materials |
Country Status (4)
Country | Link |
---|---|
AU (1) | AU748229B2 (en) |
GB (1) | GB2348196B (en) |
HK (1) | HK1031371A1 (en) |
WO (1) | WO1999028264A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11746051B2 (en) | 2020-01-24 | 2023-09-05 | Permabase Building Products, Llc | Cement board with water-resistant additive |
Families Citing this family (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6245142B1 (en) | 1999-01-12 | 2001-06-12 | Halliburton Energy Services, Inc. | Flow properties of dry cementitious materials |
US6379456B1 (en) * | 1999-01-12 | 2002-04-30 | Halliburton Energy Services, Inc. | Flow properties of dry cementitious and non-cementitious materials |
US6660080B2 (en) | 1999-01-12 | 2003-12-09 | Halliburton Energy Services, Inc. | Particulate flow enhancing additives |
ES2200716B1 (en) * | 1999-08-23 | 2005-05-01 | Impexmetal Dobris S.R.O. | BRIQUETA PROPICIA FOR THE LICUEFACCION OF THE METALLURGICAL ESCORIA AND BRIQUETAS PRODUCTION FORMS. |
US6478868B1 (en) | 1999-08-26 | 2002-11-12 | Halliburton Energy Services, Inc. | Early-enhanced strength cement compositions and methods |
DE19950106A1 (en) * | 1999-09-30 | 2001-04-05 | Schuemann Sasol Gmbh & Co Kg | Production of concrete comprises mixing concrete with water, sand, flint and paraffin bound to a carrier material |
GB0024642D0 (en) * | 2000-10-07 | 2000-11-22 | Dow Corning | Hydrophobic gypsum |
GB0024638D0 (en) | 2000-10-07 | 2000-11-22 | Dow Corning | Cementitious materials |
KR100499343B1 (en) * | 2002-11-27 | 2005-07-04 | 장산방수산업(주) | Waterproof admixture for concrete having a corrosion inhibition function |
WO2006041698A1 (en) | 2004-10-04 | 2006-04-20 | W.R. Grace & Co.-Conn. | Integrally waterproofed concrete |
GB0623232D0 (en) | 2006-11-22 | 2007-01-03 | Dow Corning | Cementitious materials |
FR2942475B1 (en) | 2009-02-26 | 2011-04-01 | Sika Technology Ag | DRY COMPOSITION COMPRISING A BINDER AND MODIFIED VEGETABLE OIL |
FR2942474B1 (en) * | 2009-02-26 | 2011-07-29 | Sika Technology Ag | DRY COMPOSITION COMPRISING BINDER AND SILICONE OIL |
EP2298709A1 (en) * | 2009-09-18 | 2011-03-23 | Omya Development AG | Concrete mix having anti-efflorescence properties and method of making concrete using the same |
MX366744B (en) * | 2012-03-23 | 2019-06-28 | Copamex S A De C V | Super-hydrophobic composition, preparation of same and super-hydrophobic paper. |
US9840440B2 (en) | 2013-11-29 | 2017-12-12 | Nano And Advanced Materials Institute Limited | Hydrophobic low shrinkage lightweight cementitious matrix |
US10829505B2 (en) | 2016-04-20 | 2020-11-10 | Dow Silicones Corporation | Lithium alkylsiliconate composition, coating, and method of making same |
EP3623354A1 (en) * | 2018-09-14 | 2020-03-18 | Sika Technology Ag | Stearate-coated nano-calcium carbonate for concrete waterproofing |
CN110041035B (en) * | 2019-05-07 | 2021-09-21 | 武汉理工大学 | C30 high-impermeability concrete with low consumption of rubber materials and preparation method thereof |
EP3750856A1 (en) * | 2019-06-13 | 2020-12-16 | Baerlocher GmbH | Hydrophobic additives for construction materials |
US10590038B1 (en) | 2019-07-01 | 2020-03-17 | Maw-Tien Lee | Producing cementitious materials with improved hydrophobicity and strength using reclaimed waste substances |
CN111517691A (en) * | 2020-05-26 | 2020-08-11 | 深圳市利泽恒有限公司 | Polymer waterproof agent, waterproof concrete material and waterproof mortar |
CN111704409A (en) * | 2020-06-18 | 2020-09-25 | 湖北合力久盛混凝土有限公司 | C30 high-impermeability concrete with low dosage of cementing materials and preparation method thereof |
DE102021111969A1 (en) | 2021-05-07 | 2022-11-10 | Fixit TM Holding GmbH | PRE-PRODUCT, FOAM CONCRETE AND ITS PRODUCTION PROCESS |
BR102021010104B1 (en) * | 2021-05-25 | 2023-12-05 | Moshe 3000 Materiais De Construção Ltda | CONCRETE ADDITIVE MANUFACTURING PROCESS |
CN115093148B (en) * | 2022-06-27 | 2023-09-15 | 深圳大学 | Hydrophobic regenerated material and preparation method and application thereof |
CN115536305B (en) * | 2022-09-30 | 2023-07-28 | 北京建筑材料科学研究总院有限公司 | Modified siliceous material and preparation method and application thereof |
CN115521121B (en) * | 2022-10-14 | 2023-11-10 | 中桔(广东)建材科技有限公司 | Corrosion-resistant cement mortar and preparation method thereof |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0393681A1 (en) * | 1989-04-20 | 1990-10-24 | TECNICHE INDUSTRIALI S.r.l. | Heat-insulating, water-repellant and flame-retarded mortars having a high ratio of mechanical properties to specific gravity |
WO1993004007A1 (en) * | 1991-08-13 | 1993-03-04 | Boral Australian Gypsum Limited | Water-resistant building material |
US5472501A (en) * | 1982-12-08 | 1995-12-05 | Elkem Materials Inc. | Concrete additive comprising a multicomponent admixture containing silica fume, its method of manufacture and concrete produced therewith |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4310486A (en) * | 1976-01-16 | 1982-01-12 | Cornwell Charles E | Compositions of cementitious mortar, grout and concrete |
-
1997
- 1997-12-03 WO PCT/SG1997/000064 patent/WO1999028264A1/en active IP Right Grant
- 1997-12-03 AU AU58934/98A patent/AU748229B2/en not_active Ceased
- 1997-12-03 GB GB0016350A patent/GB2348196B/en not_active Expired - Fee Related
-
2001
- 2001-02-23 HK HK01101335A patent/HK1031371A1/en not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5472501A (en) * | 1982-12-08 | 1995-12-05 | Elkem Materials Inc. | Concrete additive comprising a multicomponent admixture containing silica fume, its method of manufacture and concrete produced therewith |
EP0393681A1 (en) * | 1989-04-20 | 1990-10-24 | TECNICHE INDUSTRIALI S.r.l. | Heat-insulating, water-repellant and flame-retarded mortars having a high ratio of mechanical properties to specific gravity |
WO1993004007A1 (en) * | 1991-08-13 | 1993-03-04 | Boral Australian Gypsum Limited | Water-resistant building material |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11746051B2 (en) | 2020-01-24 | 2023-09-05 | Permabase Building Products, Llc | Cement board with water-resistant additive |
Also Published As
Publication number | Publication date |
---|---|
GB2348196B (en) | 2001-04-18 |
WO1999028264A1 (en) | 1999-06-10 |
GB2348196A (en) | 2000-09-27 |
GB0016350D0 (en) | 2000-08-23 |
HK1031371A1 (en) | 2001-06-15 |
AU5893498A (en) | 1999-06-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
AU748229B2 (en) | Waterproofing additive for cement and concrete comprising modified pozzolanic materials | |
FI72962B (en) | TILLSATSBLANDNING FOER BETONG OCH BRUK, FOERFARANDE FOER DESS FRAMSTAELLNING OCH DESS ANVAENDNING. | |
AU2010241328B2 (en) | Integrally waterproofed concrete | |
EP0499437B1 (en) | A method of cathodically protecting a reinforced concrete structure and the structure obtained thereby. | |
KR100655260B1 (en) | Water proof admixtures for concrete and mortar | |
KR101033652B1 (en) | Manufacturing method of liquid composition for water-proof in concrete and concrete composition using the same | |
Jahandari et al. | Effects of different integral hydrophobic admixtures on the properties of concrete | |
KR100500151B1 (en) | Method of preparing waterproof admixture for waterproofing and anticorrosive treatment of concrete, and waterproof admixture prepared thereby | |
AIshamsi et al. | Hydrophobic materials, superplasticizer and microsilica effects on setting of cement pastes at various temperatures | |
US20080271643A1 (en) | Waterproof Cement and Synergic Composition Used to Obtain High Waterproofing | |
US4762561A (en) | Volume-stable hardened hydraulic cement | |
KR100421250B1 (en) | A cement admixture for concrete-making | |
CN109485299A (en) | A kind of multiple-effect concrete structure self-waterproofing additive with self-reparing capability | |
CN110950566A (en) | High-corrosion-resistance submicron composite material and application thereof | |
KR100516758B1 (en) | High strength cement composition and method of high strength cement panel | |
KR100508207B1 (en) | Cement Admixture for high strength, shrinkage-reducing and cold-construction, and cement composite incorporating the admixture | |
US2374562A (en) | Treatment of hydraulic cement compositions | |
Sokołowska et al. | Effect of acidic environments on cement concrete degradation | |
CA1279332C (en) | Volume-stable hardened hyraulic cement | |
RU2052413C1 (en) | Additive composition for concrete mixture or surface concrete working | |
KR960012718B1 (en) | Waterproofing composition and a process for preparing cement containing the same | |
JPH02199048A (en) | Agent for providing salt blocking property used for cement, cement composition, cement mortar and concrete | |
KR100658965B1 (en) | Cement admixture and cement composition using thereof | |
KR950010809B1 (en) | Composition of waterproof | |
KR100477963B1 (en) | Dry mortar and its manufacturing method containing blast furnace slag |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FGA | Letters patent sealed or granted (standard patent) | ||
MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |