GB2334253A - Accelerator admixture for cements - Google Patents
Accelerator admixture for cements Download PDFInfo
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- GB2334253A GB2334253A GB9813204A GB9813204A GB2334253A GB 2334253 A GB2334253 A GB 2334253A GB 9813204 A GB9813204 A GB 9813204A GB 9813204 A GB9813204 A GB 9813204A GB 2334253 A GB2334253 A GB 2334253A
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- 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
- 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
- C04B28/06—Aluminous cements
-
- 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
- C04B2103/10—Accelerators; Activators
- C04B2103/12—Set accelerators
-
- 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
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
A cementitious composition includes an admixture which comprises aluminum oxide, silicon dioxide and zirconium oxide which composition, when mixed with water, is capable of setting into a hard mass with accelerated initial and final set time, early compressive strength and an increased average rate of heat evolution.
Description
IMPROVED CEMENTITIOUS COMPOSITIONS
This invention relates to improvements in cementitious compositions and in particular the use of an admixture in such compositions. The term "cementitious compositions", as used herein, is intended to mean compositions which set and harden by chemical interaction with water and are capable of doing so under water. These compositions include cementitious waterproofings, toppings, protective coatings, and the like as well as mixtures with aggregates and water such as concrete, mortar, grout and products made therefrom.
In the construction industry, and particularly in the repair of concrete structures such as highways and structural walls and platforms, and the filling of voids and holes to form stable underpinnings or foundations for machinery and heavy equipment, there has been a need for cementitious compositions which sets into a hard mass with sufficient early strength to withstand applied stresses and loads and which does so in an accelerated period of time and with an increased rate of heat evolution. There have been numerous attempts in the past to formulate admixtures for cementitious compositions with these characteristics, but such attempts have met with only limited success. The admixtures employed often produced undesirable properties and side effects such as corrosion of reinforcing steel in concrete by admixtures containing chloride, insufficient early strength gain, and long-term strength degradation. Most admixtures developed for high alumina cements were ineffective for Portland cements, while admixtures produced for
Portland cement were unsatisfactory for high alumina cements.
Examples of prior attempts at producing satisfactory admixtures are described in
M. Shimizu, T. Tano, K. Uchida and N. Kitaoka, "Concrete Additive" - Japan Kokai 79 50528,
Apr. 20, 1979; Chem Abstr., 91 128011 (1979) and in V.I. Remiznikova, T.I. Astrova, V.P.
Schmidt, M.S. Nizamov, V.N. Popko, V.P. Zuey, M.A. Loginov and A.V. Beinarovich, "Complex
Additive for a Cement-Concrete Mixture" - U.S.S.R. 697, 436, Nov. 15, 1979; Chem Abstr., 92 81279 (1980).
Accordingly, it is an object of the present invention to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength.
Another object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution.
An additional object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution and includes a plasticizing (water reducing) and defoaming agent.
A still further object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution and includes an air releasing and/or gas generating agent.
A still further object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution and includes an air entraining agent.
A still further object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution and includes a corrosion inhibitor.
A still further object of the present invention is to provide a cementitious composition including an admixture which when mixed with water will set within an accelerated period of time into a hard mass of increased early strength and which has an increased average rate of heat evolution and includes a mineral admixture.
The foregoing objects are achieved according to the present invention by the discovery of a novel admixture which consists of a combination of aluminum oxide, silicon dioxide and zirconium oxide in the proportions specified below. In addition to the admixture, the cementitious composition includes sand and water, high alumina cement or portland cement or a combination of both high alumina cement and portland cement. Plasticizing and defoaming agents, air releasing and/or gas generating agents, air entraining agents, corrosion inhibitors and mineral admixtures may also be used with the cementitious compositions of the present invention.
The range of the aluminum oxide used in the admixture of the present invention is between 70 and 96%, by weight, of the total admixture, the range of silicon dioxide is between 2 to 15%, by weight, of the total admixture, and the range of zirconium oxide is between 2 to 13%, by weight, of the total admixture.
The foregoing and other objects, features and advantages of the invention will be further apparent from the following detailed description thereof and the accompanying claims.
The invention is best illustrated by the following experiments and the results of the experiments set forth in the Tables below. In the following discussion, percentages are by weight unless otherwise indicated. In each control specimen and experiment discussed below, the water was mixed with the dry mixture and the data was then recorded. In all the control specimens and experiments, with the exception of experiments 16 and 17, the water content of the composition comprised 20% of the weight of the dry materials.
The Control Specimen for Experiments 1.2 and 3
The same control specimen was utilized for Experiments 1, 2 and 3. The control
(RTM) specimen consisted of mixing Secar # 51 high alumina cement, sold by Lafarge Calcium
Aluminates, Inc., with sand and water. The dry mixture of the control specimen included equal parts of Secar 51 high alumina cement and sand.
Experiment 1
In Experiment 1, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 47.5% and the admixture in the amount of 2.5% of the total mixture was added. The admixture comprised aluminum oxide, A1203, in the amount of 2.1% of the total mixture; silicon dioxide, SiO2, in the amount of .22% of the total mixture; zirconium oxide, ZrO2, in the amount of .18% of the total mixture. As a percentage of the admixture, the aluminum oxide comprised 84% of the admixture, the silicon dioxide comprised 8.8% of the admixture and the zirconium oxide comprised 7.2% of the admixture. With respect to the results of Experiment 1, both the initial and final set time decreased compared to the control specimen, the early (up to one day) compressive strength increased compared to the control specimen, and both the exdtherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 2
In Experiment 2, the percentage of the Secar 51 high alumina remained at 50% of the dry mixture, however, the sand content was further reduced to 45%. In this experiment, the percentage of the admixture was increased two-fold, from 2.5% to 5%, and each of the components of the admixture, the aluminum oxide, silicon dioxide and zirconium oxide was also increased two-fold (sol, the aluminum oxide was increased to 4.2%; the silicon dioxide was increased to .44%; and the zirconium oxide was increased to .36%). With respect to Experiment 2, it was noted that the increased admixture of Experiment 2 decreased the initial and final set time as compared to Experiment 1 and the control specimen; increased the early (up to one day) compressive strength as compared to Experiment 1 and the control specimen; and increased both the exotherm peak and average rate of temperature growth as compared to Experiment 1 and the control specimen.
Experiment 3
In Experiment 3, the percentage of the Secar 51 high alumina remained at 50% of the dry mixture and the sand content of the dry mixture was reduced to 40%. The admixture was increased two-fold from Experiment 2, to 10% of the dry mixture, and the amount of aluminum oxide, silicon dioxide, zirconium oxide also increased two-fold from Experiment 2 (i.e., the aluminum oxide was increased to 8.4%; the silicon dioxide was increased to .88%; and the zirconium oxide was increased to .72%). The increased amount of admixture included in the mixture of Experiment 3 further decreased the initial and final set time as compared to the prior experiments; increased the early (up to one day) compressive strengths as compared to the prior experiments and further increased the exotherm peak and average rate of temperature growth as compared to the prior experiments.
Experiment 4
A further control specimen, similar to the earlier control specimen for Experiments 1 to 3 was conducted with respect to Experiment 4. This further control specimen substituted Fondu,high alumina cement, sold by Lafarge Calcium Aluminates, Inc., for the Secar 51 high alumina cement. In all other respects the control specimen for Experiment 4 was the same as the control specimen for Experiments 1, 2 and 3. In Experiment 4, the percentage of the Fondu high alumina cement remained at 50% of the dry mixture, but the sand content was reduced from 50%, as in the control specimen, to 40%. The same admixture as in Experiment 3, namely 8.4% of aluminum oxide; .88% of silicon oxide and .72% of zirconium oxide, was added. With respect to Experiment 4, both the initial and final set times decreased as compared to its corresponding control specimen; the early (up to one day) compressive strength increased as compared to the control specimen and both the exotherm peak and average rate of temperature growth increased as compared to the control specimen. It was noted that the compressive strength at six hours for both Experiment 4 and the control specimen were the same. A possible explanation is that the admixture's accelerating effect occurs earlier on the Fondu HAC than on the other cements. It may also be the case that the test results fall within the 10% error of experiments typical for cementitious materials.
Experiment 5
Another control specimen, similar to the earlier control specimens, was conducted with respect to Experiment 5. In this experiment, Lumnite high alumina cement, sold by Lehigh
Portland Cement Company, was substituted for the Secar 51 high alumina cement and the Fondu high alumina cement of the prior control specimen. The control specimen for Experiment 5 was the same as the earlier control specimens in all other respects.
In Experiment 5, the percentage of Lumnite high alumina cement remained at 50% of the dry mixture, but the sand content was reduced from 50%, as in the control specimen, to 40%. The same admixture as in Experiments 3, 4 and 5, namely 8.4% of aluminum oxide; .88% of silicon oxide and .72% of zirconium oxide, was added. With respect to Experiment 5, both the initial and final set times decreased as compared to its corresponding control specimen; the early (up to one day) compressive strength increased as compared to the control specimen, and both the exotherm peak and average rate of temperature growth increased as compared to the control specimen.
The following Table 1 includes the quantitative results of Experiments 1 to 5.
TABLE 1
Experiment No. 1 2 3 4 5
Ingredients, %
Properties Control Control Control
Secar 51 HAC 50.0 50.0 50.0 50.0 -
Fondu HAC - - - - 50.0 50.0 -
Lumnite HAC - - - - - - 50.0 50.0
ASZ admixture, total 2.5 5.0 10.0 10.0 - 10.0 including A1203 2.1 4.2 8.4 - 8.4 - 8.4
SiO2 - 0.22 0.44 0.88 0.88 0.88
ZrO2 - 0.18 0.36 0.72 - 0.72 - 0.72
Sand 50.0 47.5 45.0 40.0 50.0 40.0 50.0 40.0
Mixing water, % by weight of dry batch 20% FOR ALL MIXES
Set time, min.
Initial 279 221 166 128 193 145 330 159
Final 336 260 180 150 235 170 375 194
Compressive Strength, psi
3 hrs. - 200 3000 -
4 hrs. - - 1350 5875 - 3900 - 2850
5 hrs. - 2400 4800 6075 4100 4750 4300
6 hrs. 650 5800 6050 6175 5350 5350 - 4550
1 dav 8175 8660 8710 9060 6875 7200 7100 7375 Exotherm peak
Temperature, OF 218 232 240 247 221 241 209 214 Tlrne, min. 462 362 314 223 310 215 469 338
Average rate of temperature's zrowth. F/min. 0.31 0.44 0.54 0.78 0.48 0.79 0.29 0.42 Experiment 6
The control specimen for Experiment 6 was similar to the previous control specimens but substituted portland gray cement, type II, sold by Lehigh Portland Cement
Company, for the cements of the previous control specimens. The portland gray cement comprised 50% of the dry mixture and the sand comprised 50% of the dry mixture. "Portland cement", as used herein, includes those cements normally understood in the art to be "portland cements", as described in the designation ASTM C 150.
In Experiment 6, the percentage of the portland cement, type II, remained the same at 50% of the dry mixture, but the sand content was reduced to 40% of the dry mixture. The admixture comprising 10% of the dry mixture was added. The admixture formulation was the same as in Experiments 3, 4 and 5, namely aluminum oxide in the amount of 8.4% of the total mixture; silicon dioxide in the amount of .88% of the total mixture; zirconium oxide in the amount of .72% of the total mixture. With respect to the results of Experiment 6, both the initial and final set time decreased compared to the control specimen, the compressive strength (up to one day) increased compared to the control specimen, and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 7
The control specimen for Experiment 7 was identical to the control specimen for
Experiment 6, and Experiment 7 was identical to Experiment 6, with the exception that in both the control specimen and Experiment 7, portland cement, type m, sold by Lehigh Portland
Cement Company, replaced the portland cement, type II of Experiment 6. With respect to the results of Experiment 7, both the initial and final set time decreased with respect to the control specimen, the compressive strength at 5, 6, 7 and 8 hours increased, and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
The following Table 2 includes the quantitative results of Experiments 6 and 7.
TABLE 2 Experiment No. 6 7
Ingredients, %
Properties Control Control
Portland cement T-II 50.0 50.0
(Lehigh, gray)
Portland cement T-E 50.0 50.0
(Lehigh, white)
ASZ-admixture, total - 10.0 10.0
including: A1203 - 8.4 - 8.4
SiO2 0.88 - 0.88 Zero, 0.72 - 0.72
Sand 50.0 40.0 50.0 40.0
Mixing water % by weight of dry batch 20% FOR ALL MIXES
Set time, min
Initial 205 191 147 120
Final 355 271 202 175
Compressive strength, psi
5 hrs. - - - 325
6 hrs. - 175 225 625
7 hrs. 10S125 275 500 1125
8 hrs. 200 425 725 1950
1 dav 3500 4000 4550 5750
Exotherm peak
Temperature, F 113 130 151 164
Time, min. 570 480 438 346
Average rate of temperature's growth. OFlmfn. 0.07 0.12 0.18 0.28
Experiment 8
The control specimen for Experiment 8 consisted of mixing Secar 51 high alumina cement in the amount of 37.5% of the dry mix, portland gray cement, type H, in the amount of 12.5% of the dry mix and sand in the amount of 50% of the dry mix. In Experiment 8, the percentage of the Secar 51 high alumina cement and the portland cement, type II remained the same as the control specimen but the sand content was reduced to 45% and replaced by the admixture in the same percentages as Experiment 2, namely aluminum oxide in the amount of 4.2% of the dry mixture; silicon dioxide in the amount of .44% of the dry mixture; zirconium oxide in the amount of .36% of the dry mixture. With respect to the results of Experiment 8, both the initial and final set time decreased compared to the control specimen, the compressive strength at 2, 3 and 6 hours increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 9
The control specimen for Experiment 9 was the same as the control specimen for
Experiment 8. In Experiment 9, the percentage of the Secar 51 high alumina cement and the portland cement, type II remained the same as the control specimen but the sand content was reduced to 40%, and replaced by the admixture comprising aluminum oxide in the amount of 8.4% of the dry mixture; silicon dioxide in the amount of .88% of the dry mixture; zirconium oxide in the amount of .72% of the dry mixture. With respect to the results of Experiment 9, both the initial and final set time decreased with respect to the control specimen, the compressive strength at 2, 3 and 6 hours increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
The following Table 3 includes the quantitative results of Experiments 8 and 9.
TABLE 3
Experiment 8 9
Ingredients, %
Properties ~ Control
Secar 51 HAC 37.5 37.5 37.5
Portland T-II 12.5 12.5 12.5
ASZ-admixture, total
including: - 5.0 10.0
A1203 - 4.2 8.4
SiO2 - 0.44 0.88 Zero, - 0.36 0.72
Sand 50.0 45.0 40.0
Mixing water, % by weight of dry batch 20% FOR ALL MIXES
Set time, min.
Initial 127 82 71 Fmal 150 87 81
Compressive strength, psi
2 hrs. - 950 1650
3 hrs. 800 3900 4000 6hrs. 4550 4675 5150 Exotherm peak
Temperature, F 220 221 223
Time, min. 230 164 171
Average rate of temperature's growth. F/min 0.64 0.91 0.88
Experiments 10 through 15
- In General
Experiments 10 through 15 were designed to determine the limits of each of the compounds used in the admixture. Thus, the aluminum oxide, the silicon dioxide, and the zirconium oxide were each tested separately in a cementitious compound comprising Secar 51 high alumina cement, sand and water. The same control specimen was utilized for Experiments 10 through 15. The control specimen comprised a mixture of Secar 51 high alumina cement with sand. The dry mixture of the control specimen included equal parts of Secar 51 high alumina cement and sand. The water content of the composition comprised 20% of the weight of the dry materials.
Experiment 10
In Experiment 10, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e.,50%; however, the sand content was reduced to 46.5% and aluminum oxide in the amount of 3.5% of the total mixture was added. The amount of aluminum oxide, 3.5% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 5% of the total dry mix, and that the aluminum oxide portion of the admixture would be 70%. Thus, the aluminum oxide would be 70% of the 5% total dry mix or 3.5%. Neither silicon dioxide nor zirconium oxide was added to the mixture. With respect to the results of Experiment 10, both the initial and final set time decreased compared to the control specimen, the early (up to one day) and seven day compressive strengths increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 11
In Experiment 11, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 40.4% and aluminum oxide in the amount of 9.6% of the total mixture was added. The amount of aluminum oxide, 9.6% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 10% of the total dry mix, and that the aluminum oxide portion of the admixture would be 96%.
Thus, the aluminum oxide would be 9.6% of the total dry mix. Neither silicon dioxide nor zirconium oxide was added to the mixture. With respect to the results of Experiment 11, both the initial and final set time decreased compared to the control specimen and to Experiment 10, the early (up to one day) and seven day compressive strengths increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen and to Experiment 10. The compressive strength of
Experiment 11 compared to Experiment 10 increased at four and six hours, but decreased at five, seven and eight hours and one and seven days.
Experiment 12
In Experiment 12, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 49.9% and silicon dioxide in the amount of .1% of the total mixture was added. The amount of silicon dioxide, ,1% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 5% of the total dry mix, and that the silicon dioxide portion of the admixture would be 2%. Thus, the silicon dioxide would be 2% of the 5% total dry mix or .1%. Neither aluminum oxide nor zirconium oxide was added to the mixture. With respect to the results of Experiment 12, both the initial and final set time decreased compared to the control specimen, but increased compared to Experiments 10 and 11, the early (up to one day) and seven day compressive strengths increased compared to the control specimen, but decreased compared to Experiments 10 and 11 and the exotherm peak decreased compared to the control specimen and to Experiments 10 and 11. The average rate of temperature growth increased compared to the control specimen, but decreased compared to Experiments 10 and 11.
Experiment 13
In Experiment 13, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 48.5% and silicon dioxide in the amount of 1.5% of the total mixture was added. The amount of silicon dioxide, 1.5% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 10% of the total dry mix, and that the silicon dioxide portion of the admixture would be 15%. Thus, the silicon dioxide would be 15% of the 10% total dry mix or 1.5%. Neither aluminum oxide nor zirconium oxide was added to the mixture. With respect to the results of Experiment 13, the initial set time decreased with respect to the control specimen and with respect to Experiments 10 through 12. The final set time decreased with respect to the control specimen and
Experiments 10 and 12 but increased with respect to Experiment 11. The compressive strength at four hours increased with respect to Experiments 10 and 11; at five hours increased with respect to Experiments 10 and 11; at seven hours increased with respect to the control specimen and Experiment 12 but decreased with respect to Experiments 10 and 11; at eight hours increased with respect to the control specimen and Experiment 12 but decreased with respect to Experiment 10 and 11; at one day increased with respect to the control specimen and Experiment 12 but decreased with respect to Experiments 10 and 11; and at seven days increased with respect to the control specimen and Experiment 12 and decreased with respect to Experiments 10 and 11. The exotherm peak increased with respect to the control specimen and Experiment 12 and decreased with respect to Experiments 10 and 11. The average rate of temperature growth increased compared to the control specimen and with respect to Experiments 10 through 12.
Experiment 14
In Experiment 14, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, lie., 50%; however, the sand content was reduced to 49.9% and zirconium oxide in the amount of .1% of the total mixture was added. The amount of zirconium oxide, .1% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 5% of the total dry mix, and that the zirconium oxide portion of the admixture would be 2%. Thus, the zirconium oxide would be 2% of the 5% total dry mix or .1%. Neither aluminum oxide nor silicon dioxide was added to the mixture. With respect to the results of Experiment 14, the initial set time was the same as the control specimen and the final set time was virtually the same as the control specimen. The early (up to one day) compressive strengths increased compared to the control specimen and Experiment 12 but decreased compared to Experiments 10, 11 and 13.
The seven day compressive strength increased compared to the control specimen and Experiment 12 but decreased compared to Experiments 10, 11 and 13. The exotherm peak temperature increased compared to the control specimen and Experiment 12 and decreased compared to
Experiments 10, 11 and 13. The average rate of temperature growth increased with respect to the control specimen, remained the same with respect to Experiment 12, and decreased compared to Experiments 10, 11 and 13.
Experiment 15
In Experiment 15, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, ive, 50%; however, the sand content was reduced to 48.5% and zirconium oxide in the amount of 1.5% of the total mixture was added. The amount of zirconium oxide, 1.5% of the total mixture, was selected on the assumption that the total admixture (containing aluminum oxide, silicon dioxide and zirconium oxide) would comprise 10% of the total dry mix, and that the zirconium oxide portion of the admixture would be 15%.
Thus, the zirconium oxide would be 15% of the 10% total dry mix or 1.5%. Neither aluminum oxide nor silicon dioxide was added to the mixture. With respect to the results of Experiment 15, the initial set time was less than the control specimen and Experiment 14, but greater than
Experiments 10 through 13. The final set time was less than the control specimen and
Experiment 14, but greater than Experiments 10 through 13. The compressive strength for seven and eight hours increased compared to the control specimen and Experiment 14 but decreased compared to Experiments 10 through 13. The compressive strength for one day increased compared to the control specimen and Experiments 12 and 14 but decreased with respect to
Experiments 10, 11 and 13. The compressive strength for seven days increased compared to the control specimen and Experiment 12, was the same as Experiment 14 and decreased compared to Experiments 10, 11 and 13. The exotherm peak temperature increased compared to the control specimen and Experiments 12 and 14 and decreased compared to Experiments 10, 11 and 13.
The average rate of temperature growth increased with respect to the control specimen,
Experiments 12 and 14 and decreased compared to Experiments 10, 11 and 13.
The following Table 4 sets forth the results of Experiments 10 through 15. When the amount of admixture was lower than that of Experiments 10 through 15, the accelerating effect was insignificant or absent. At higher amounts of admixture, other unacceptable properties were present (, the material was too stiff to be compacted properly).
TABLE 4
Experiment No. 10 11 12 13 14 15
Ingredients, % properties Control
HAC (Secar 51) 50.0 50.0 50.0 50.0 50.0 50.0 50.0 A1203 - 3.5 9.6 - - - SiO2 - - - 0.1 1.5 - - Zr 2 - - - - - 0.1 1.5
Sand 50.0 46.5 40.4 49.9 48.5 49.9 48.5
Mixing water, % by wgt. of dry batch 20% FOR ALL MINES Set time, minutes
Initial 312 169 144 277 141 312 285
Final 357 192 169 320 173 356 332
Compressive
strength, psi 3 Hrs. - - 350 - 4 Hrs. - 825 1950 3500 5 Hrs. 5725 5650 6400
6 Hrs. - 7525 7575 - 6600 - 7 Hrs. 125 8050 7900 1350 7100 175 800 8 Hrs. 1100 8125 8100 5010 7150 1200 4850
1 Day 6325 8475 8250 6800 8000 6850 7050
7 Days 8350 10650 10550 8450 9800 8550 8550 Exotberm peak temperature, F 218 241 243 213 232 222 226
time, minutes 513 339 371 463 293 486 450
Average rate of
temperature's
growth, F/min. 0.29 0.50 0.47 0.31 0.55 0.31 0.35
Experiments 16 and 17 In General
Experiments 16 and 17 were designed to determine the effect of certain plasticizing agents on the cementitious composition. The plasticizing agents were Lomar DF, which includes a defoamer, and is sold by Henkel Corp., and MCG SC9, which is sold by
Morristown Chemical Group. The plasticizing agents may include naphthalene sulfonate based compounds, melamine sulfonate based compounds and ligmosulphonate based compounds.
Experiment 16
The control specimen comprised a mixture of Secar 51 high alumina cement with sand. The dry mixture of the control specimen included 50% of Secar 51 high alumina cement, 49.9% of sand and 0.1% of MCG-SC9. The water content of the composition comprised 16.5% of the weight of the dry materials.
In Experiment 16, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e. 50%; however, the sand content was reduced to 44.9% and
MCG-SC9 in the amount of .lay of the total mixture was added. The amount of water was increased to 18.75% of the weight of the dry material. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 16, the final set time was reduced compared to the control specimen (because of the previously noted retardation effect of the plasticizing agent, the initial set time was not tested, nor was compressive strength at six or eight hours).
The one day and seven day compressive strengths increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 17
The control specimen comprised a mixture of portland cement, type II, sold by
Lehigh Portland Cement Company, with sand. The dry mixture of the control specimen included 50% of such cement, 49.8% of sand and .2% of Lomar DF. The water content of the composition comprised 18.25% of the weight of the dry materials.
In Experiment 17, the percentage of the Lehigh type II cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 44.8% and Lomar
DF in the amount of .2% of the total mixture was added. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 17, both the initial and final set times were
reduced compared to the control specimen. The eight hours, one day and seven day compressive
strengths increased compared to the control specimen and both the exotherm peak and average
rate of temperature growth increased compared to the control specimen. The results of
Experiments 16 and 17 are shown in Table 5.
TABLE 5
Experiment No. 16 17
Ingredient, %
Properties Control Control
HAC (Secar 51) 50.0 50.0
Portland (Lehigh T-II) - - 50.0 50.0 ASZ - admixture total - 5.0 5.0
including A12 3 4.15 4.15 SiO2 - 0.425 0.425 Z102 - 0.425 0.425 water-reducers
Lomar DF - - 0.2 0.2
MCG-SC9 0.1 0.1 -
Sand 49.9 44.9 49.8 44.8
Mixing Water 16.5 18.75 18.25 18.75
Set time
Initial - - 247 204
Final 887 819 367 340
Compressive strength, psi
6 Hrs.
8 Hrs. - - 250 600
1 Day 3000 10800 4500 4925
7 Davs 6925 12700 7100 7725
Exotherm peak Temperature F 128 153 120 131
Time, minutes 3175 1495 520 417
Avg. rate of temperature's growth, F/minutes 0.02 0.06 0.09 0.14
Experiments 18 and 19
- In General
Experiments 18 and 19 were designed to determine the effect on the cementitious composition of the presence of certain air releasing and/or gas generating agents. The air releasing agent was fluidized coke sold by Five Star Products, Inc. under the trademark "PLA" (hereinafter "PLA") and the gas generating agent was azodicarbonamide sold by Uniroyal
Chemical under the trademark "AZ-130" (hereinafter "AZ-130"). The water content of
Experiments 18 and 19, and their respective control specimen was 20% of the weight of the dry mixture.
Experiment 18
The control specimen comprised a mixture of Secar 51 high alumina cement with sand. The dry mixture of the control specimen included 50% of Secar 51 high alumina cement, 47% sand and 3% of PLA.
In Experiment 18, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 42% and PLA in the amount of 3% of the total mixture was included. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 18, the initial and final set times were reduced compared to the control specimen. In the plastic state, the volume change of the composition was less than the volume change of the control specimen. The seven hours, eight hour and one day compressive strengths increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
Experiment 19
The control specimen comprised a mixture of Secar 51 high alumina cement with sand. The dry mixture of the control specimen included 50% of Secar 51 high alumina cement and 49.99% sand and .01% of AZ-130.
In Experiment 19, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 44.99% and
AZ-130 in the amount of .01% of the total mixture was included. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 19, the initial and final set times was reduced compared to the control specimen. In the plastic state, the volume change of the composition was less than the volume change of the control specimen. The one day compressive strengths increased compared to the control specimen, and both the exotherm peak and the average rate of temperature growth increased compared to the control specimen. The following
Table 6 sets forth the results of Experiments 18 and 19.
TABLE 6
Experiment No. 18 19
Ingredient, %
Properties Control Control
HAC (Secar 51) 50.0 50.0 50.0 50.0
ASZ- admixture
total - 5.0 - 5.0 including Al2O3 4.15 4.15
SiO2 - 0.425 - 0.425
ZrO2 - 0.425 - 0.425
PLA 3.0 3.0 - AZ-130 - - 0.01 0.01
Sand 47.0 42.0 49.99 44.99
Mixing Water, % 20% FOR ALL MIXES
Set time, minutes
Initial 326 197 363 260
Final 369 220 422 275
Volume changes in plastic state, % +1.78 +1.65 +0.03 +0.025
Compressive strength, psi
4 Hrs. - 425
5 Hrs. - 4100 - 500
6 Hrs. - 5400 - 2250
7 Hrs. 5000 6225 - 5200
8 Hrs. 5200 6625 5300
1 Day 6250 7875 6600 8075 Exotherm peak:
Temperature, F 225 246 230 248
Time, minutes 465 368 480 385
Avg. rate of ternperature's
growth, Flrninutes 0.33 0.47 0.33 0.46
Experiment 20
Experiment 20 was designed to determine the effect on the cementitious composition of an air-entraining agent, vinsolrresin (hereinafter "NVX").
The control specimen comprised a mixture of Secar 51 high alumina cement with sand. The dry mixture of the control specimen included 50% of Secar high alumina cement and 49.99% sand and .01% of NVX. The water content of Experiment 20 was 20% of the weight of the dry mixture.
In Experiment 20, the percentage of the Secar 51 high alumina cement remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 44.99% and
NVX in the amount of .01% of the total mixture was included. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 20, the initial and final set times were reduced compared to the control specimen. The seven hours, eight hours and one day compressive strengths increased compared to the control specimen, the exotherm peak remained the same as the control specimen and the average rate of temperature growth increased compared to the control specimen. The results of Experiment 20 are shown in Table 7.
TABLE 7
Experiment No. 20
Ingredients, % Properties Control
HAC (Secar 51) 50.0 50.0 ASZ-admixture total 5.0
including Al2O3 4.15
SiO2 0.425
ZRO2 - 0.425
NVX 0.01 0.01
Sand 49.99 44.99
Mixing Water, % 20.0
Set time, minutes
Initial 290 211
Final 345 241
Compressive strength. psi
4 Hrs.
5 Hrs. - 1975
6 Hrs. 300 3630 7 Hrs. 2900 5025 8 Hrs. 4350 5275 l Day 5975 6800 Exotnerm peak
Temperature, F 222 222
Time, minutes 636 443
Avg. rate of temperature's
growth, F/rninutes 0.24 0.33
Experiment 21
Experiment 21 was designed to determine the effect on the cementitious composition of a corrosion inhibitor NaNO2.
The control specimen comprised a mixture of portland cement, type II with sand.
The dry mixture of the control specimen included 50% of such cement and 49.0% sand and 1% of NaNO2. The water content of Experiment 20 was 20% of the weight of the dry mixture.
In Experiment 21, the percentage of the portland cement, type II remained the same as the control specimen, i.e., 50%; however, the sand content was reduced to 44% and
NaNO2 in the amount of 1% of the total mixture was included. Admixture in the amount of 4.15% of aluminum oxide, .425% of silicon dioxide and .425% of zirconium oxide was included in the mixture. With respect to the results of Experiment 21, the initial and final set times were reduced compared to the control specimen. The six hours, seven hours, eight hours and one day compressive strengths increased compared to the control specimen, and both the exotherm peak and the average rate of temperature growth increased compared to the control specimen. The results of Experiment 21 are shown in Table 8.
TABLE 8
Experiment No. 21
Ingredients, %
Properties Control
Portland, T-1I 50.0 50.0
ASZ-admixture
total 5.0
including Al2O3 - 4.15
SiO2 - 0.425 Zero: 0.425 NaN02 1.0 1.0
Sand 49.0 44.0
Mixing water, % 20.0
Set time, minutes
Initial 228 224 Final 324 303
Compressive strength, psi 6 Hrs. 125 125
7 Hrs. 250 275
8 Hrs. 400 500 1 Dav 3350 4000 Exotherm peak
Temperature, F 118 122 Time, minutes 533 503
Avg. rate of temperature's growth, F/rninutes 0.08 0.1
Experiment 22
Experiment 22 was designed to determine the effect on the cementitious composition of the presence of a mineral admixture, class C fly ash.
The control specimen comprised a mixture of portland cement, type II with sand.
The dry mixture of the control specimen included 40% of cement, 50% of sand and 10% of fly ash Class C. The water content of the control specimen and Experiment 22 comprised 20% of the weight of the dry materials.
In Experiment 22, the percentage of the portland cement, type II remained the same as the control specimen, i.e., 40%; however, the sand content was reduced to 40% and fly ash Class C in the amount of 10% of the total mixture was added. Admixture in the amount of 8.3% of aluminum oxide, .85% of silicon dioxide and .85% of zirconium oxide was included in the mixture. With respect to the results of Experiment 22, the initial and final set times were reduced compared to the control specimen. The eight hour, twelve hour and one day compressive strengths increased compared to the control specimen and both the exotherm peak and average rate of temperature growth increased compared to the control specimen.
The results of Experiment are shown in Table 9.
TABLE 9
ExPeriment No. 22
Ingredients. %
Properties Control
Portland T-II 40.0 40.0
Fly ash Class C 10.0 10.0
ASZ-admixture
total 10.0
including Awl203 8.3
SiO2 - 0.85 Zero, - 0.85
Sand 50.0 40.0
Mixing water, % 20.0
Set time, minutes
Initial 334 235
Final 432 325 Compressive strength, psi
6 Hrs. - - 8 Hrs. 50 175
12 Hrs. 500 1000
1 Day 2325 2850 Exotherm peak
Temperature, F 108 109
Time, minutes 720 588 Avg. rate of temperature
growth, F/minutes 0.05 0.06
While the invention disclosed herein is calculated to provide an improved admixture for a cementitious system over those described in the prior art, it will be appreciated that alternate embodiments may be devised by those skilled in the art. It is therefore intended that the appended claims cover all modifications or embodiments as fall within the claims of the present invention.
Claims (19)
1. A cementitious composition which when mixed with water is capable of setting into a hard mass with accelerated initial and final set time and an increased average rate of heat evolution, said cementitious composition comprising an admixture of aluminum oxide, silicon dioxide and zirconium oxide.
2. A cementitious composition as recited in claim I wherein the aluminum oxide is present in the amount of 70 to 96% by weight of the admixture; the silicon dioxide is present in the amount of 2 to 15% by weight of the admixture, and the zirconium oxide is present in the amount of 2 to 15% by weight of the admixture.
3. A cementitious composition as recited in claim 1 or 2 and further comprising a high alumina cement.
4. A cementitious composition as recited in claim 1 or 2 and further comprising portland cement.
5. A cementitious composition as recited in claim 1 or 2 and further comprising a high alumina cement and portland cement.
6. A cementitious composition as recited in claims 1, 2, 3, 4 or 5 and further comprising a plasticizing, water reducing, and defoaming agent.
7. A cementitious composition as recited in claim 6 and wherein the plasticizing, water reducing, and defoaming agent is a naphthalene sulfonate compound or melamine sulfonate compound or a ligmosulphonate based compound.
8. A cementitious composition as recited in claims 1, 2, 3, 4 or 5 and further comprising an air releasing and/or gas generating agent
9. A cementitious composition as recited in claim 8, in which the air releasing and/or gas generating agent is fluidized coke and the gas generating agent azodicarbonamide.
10. A cementitious composition as recited in claims 1, 2, 3, 4 or 5 and further comprising an air-entraining agent.
11. A cementitious composition as recited in claim 10 wherein the airentraining agent is vinsol resin.
12. A cementitious composition as recited in claims 1, 2, 3, 4 or 5 and further comprising a corrosion inhibitor.
13. A cementitious composition as recited in claim 12 in which the corrosion inhibitor is sodium nitrite.
14. A cementitious composition as recited in claims 1, 2, 3, 4 or 5 and further comprising a mineral admixture.
15. A cementitious composition as recited in claim 14 wherein the mineral admixture is fly ash.
16. A method for accelerating the set time, increasing the early compressive state and increasing the average rate of heat evolution of a cementitious system which comprises adding an admixture thereto comprising aluminum oxide, silicon dioxide and zirconium oxide.
17. The method according to claim 16 wherein the added aluminum oxide is present in the amount of 70 to 96% by weight of the admixture, the silicon dioxide is present in the amount of 2 to 15% by weight of the admixture, and the zirconium oxide is present in the amount of 2 to 15% by weight of the admixture.
Is. Acementitious composition substantially as herein described with reference to the
examples.
19. A method according to claim 16 substantially as herein described with reference
to the examples.
Applications Claiming Priority (1)
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US2487198A | 1998-02-17 | 1998-02-17 |
Publications (2)
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GB2334253A true GB2334253A (en) | 1999-08-18 |
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Family Applications (1)
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GB9813204A Withdrawn GB2334253A (en) | 1998-02-17 | 1998-06-18 | Accelerator admixture for cements |
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CA (1) | CA2237702A1 (en) |
FR (1) | FR2774982A1 (en) |
GB (1) | GB2334253A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006136279A2 (en) * | 2005-06-24 | 2006-12-28 | Construction Research & Technology Gmbh | Gas-forming agent for cement composition |
EP2075240B1 (en) * | 2007-12-20 | 2013-02-27 | Sika Technology AG | Catalyst for reactivation of delayed cementitious systems |
CN105254257A (en) * | 2015-11-19 | 2016-01-20 | 泰兴市和庆机械配件厂 | Method for preparing fast-foamed door core |
EP3100990A1 (en) * | 2015-06-05 | 2016-12-07 | Kerneos | Binder composition and mortar composition, especially self-levelling mortar composition, having improved polishing resistance |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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FR2987835B1 (en) * | 2012-03-07 | 2014-03-14 | Saint Gobain Ct Recherches | SELF-LEVELING CONCRETE. |
CN103601454A (en) * | 2013-11-22 | 2014-02-26 | 济南大学 | Preparation method of light-weight thermal mortar |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS63242951A (en) * | 1987-03-31 | 1988-10-07 | 日本セメント株式会社 | Method of preventing efflorescence of mortar or concrete hardened body |
JPH07196351A (en) * | 1993-12-28 | 1995-08-01 | Chichibu Onoda Cement Corp | Quick setting material for cement and method for promoting setting and hardening of concrete or mortar |
-
1998
- 1998-05-14 CA CA002237702A patent/CA2237702A1/en not_active Abandoned
- 1998-06-18 GB GB9813204A patent/GB2334253A/en not_active Withdrawn
- 1998-06-25 FR FR9808091A patent/FR2774982A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63242951A (en) * | 1987-03-31 | 1988-10-07 | 日本セメント株式会社 | Method of preventing efflorescence of mortar or concrete hardened body |
JPH07196351A (en) * | 1993-12-28 | 1995-08-01 | Chichibu Onoda Cement Corp | Quick setting material for cement and method for promoting setting and hardening of concrete or mortar |
Non-Patent Citations (2)
Title |
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WPI Abstract Accession No. 88-327720[46] & JP 630242951 A * |
WPI Abstract Accession No. 95-299385[39] & JP 070196351 A * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006136279A2 (en) * | 2005-06-24 | 2006-12-28 | Construction Research & Technology Gmbh | Gas-forming agent for cement composition |
WO2006136279A3 (en) * | 2005-06-24 | 2007-03-29 | Constr Res & Tech Gmbh | Gas-forming agent for cement composition |
EP2075240B1 (en) * | 2007-12-20 | 2013-02-27 | Sika Technology AG | Catalyst for reactivation of delayed cementitious systems |
EP3100990A1 (en) * | 2015-06-05 | 2016-12-07 | Kerneos | Binder composition and mortar composition, especially self-levelling mortar composition, having improved polishing resistance |
WO2016193477A1 (en) * | 2015-06-05 | 2016-12-08 | Kerneos | Binder composition and mortar composition, especially self-levelling mortar composition, having improved polishing resistance |
CN105254257A (en) * | 2015-11-19 | 2016-01-20 | 泰兴市和庆机械配件厂 | Method for preparing fast-foamed door core |
Also Published As
Publication number | Publication date |
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CA2237702A1 (en) | 1999-08-17 |
FR2774982A1 (en) | 1999-08-20 |
GB9813204D0 (en) | 1998-08-19 |
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