Showing papers on "Cement published in 1972"
819 citations
398 citations
TL;DR: In this article, the authors show that the lower compacted density of fly ash relative to conventional earthfill recommends its use when a fill or embankment must be constructed over soft, compressible ground.
Abstract: The lower compacted density of fly ash relative to conventional earthfill recommends its use when a fill or embankment must be constructed over soft, compressible ground. Field evidence to date indicates that compressibility or settlement of compacted fly ash fills is not significant. Long-term field settlements cannot be predicted satisfactorily on the basis of short-term laboratory tests because fly ash exhibits age-hardening or pozzolanic properties. Low-level additions of lime to the fly ash before compaction accentuate this behavior. Frost susceptibility likewise is not as serious a problem in compacted fly ash as might be presumed from its grain size distribution. Gradation alone does not suffice as a criterion of frost susceptibility; pozollanic properties also play an important role. Undesirable frost heave in compacted fly ash can be reduced to tolerable levels by addition of lime or cement.
168 citations
TL;DR: In this article, the authors reported that the strength gain of carbonated mortars reached a plateau at three days while the non-carbonated samples continued to gain strength and finally exceeded the strength of the carbonated samples at 14 days.
119 citations
TL;DR: In this paper, the first of a series on hardened portland cement pastes of low porosity, prepared with water-cement ratios of 0.2 and 0.3, was presented.
81 citations
TL;DR: In this article, preliminary studies of the chemical composition of individual particles and local areas in hydrated cement pastes were carried out using a scanning electron microscope-energy dispersive x-ray spectrometer combination.
75 citations
TL;DR: In this paper, the influence of factors such as age, water/cement ratio, temperature and moisture content on specific heat, thermal expansion and diffusivity of cement paste, aggregates and concrete are discussed.
72 citations
Patent•
20 Apr 1972TL;DR: In this paper, the authors discuss ADDITIVES for CEMENT COMPOSITIONS at high temperatures. But they do not discuss the ADDITIVE and METHODs of CEMENTing High TEMPERATURE WELL FORMATIONS EMPOLYING the CEMENT Compositions.
Abstract: THIS SPECIFICATION DISCLOSES ADDITIVES FOR RETARDING THE SETTLING TIME OF CEMENT COMPOSITIONS AT HIGH TEMPERATURES WHICH ARE BASICALLY COMPRISED OF MIXTURES OF A LIGNOSULFONIC ACID SALT AND A PENTABORIC ACID SALT, NOVEL CEMENT COMPOSITONS CONTAINING THE ADDITIVES AND METHODS OF CEMENTING HIGH TEMPERATURE WELL FORMATIONS EMPOLYING THE CEMENT COMPOSITIONS.
65 citations
TL;DR: In this paper, the pore volume and surface distributions of three hardened pastes of hydrated dicalcium silicate, prepared with water to solid weight ratios, w/s, of 0.45, 0.57, and 0.70, were determined by water vapor adsorption-desorption isotherms.
62 citations
TL;DR: In this paper, the compressive strength of low-porosity pastes made from a Type I and a Type II clinker clinker was investigated and the effect of different grinding aids, surface of the cement, water-cement ratio (0.2 and 0.3), temperature of hydration (5°, 25°, and 50°), and the age of the paste was determined.
58 citations
TL;DR: In this article, a 3 vol % addition of the high-modulus carbon fibre to cement results in a twofold increase in the modulus of elasticity and a five-fold increase of the tensile strength over the values of the unreinforced matrix.
Patent•
01 May 1972TL;DR: In this article, a specification for a lightweight hydraulic cement is given for the use of lightweight slurries formed by combining this lightweight cement with water, and to lightweight concrete formed by the setting of the slurries.
Abstract: This specification is directed to a lightweight hydraulic cement, to the use of lightweight slurries formed by combining this lightweight cement with water, and to lightweight concrete formed by the setting of the slurries. The lightweight hydraulic cement is comprised of hydraulic cement, anhydrous sodium metasilicate, and hollow sealed spheres; a lightweight slurry is formed by mixing the lightweight cement with water and the slurry is used for treating wells that penetrate the earth. This lightweight slurry may also be used for forming lightweight concrete which in turn is useful for such things as building material.
TL;DR: In this article, the exploratory studies on low porosity portland cement pastes were conducted and the clinker grinding and paste preparation method were reported in the previous paper in this series (1).
Patent•
01 Mar 1972
TL;DR: A hydraulic cement-containing product is made from a hydraulic cement admixture containing a low concentration of water by homogeneously admixing into a dry mix of hydraulic cement and aggregate, first, an aqueous solution of a watersoluble alkali compound, such as ammonium hydroxide, and then a water-soluble carbohydrate such as molasses and water sufficient to provide an admixture that is cohesive and plastic as mentioned in this paper.
Abstract: A hydraulic cement-containing product is made from a hydraulic cement admixture containing a low concentration of water by employing a hydraulic cement admixture prepared by homogeneously admixing into a dry mix of a hydraulic cement and aggregate, first, an aqueous solution of a water-soluble alkali compound, such as ammonium hydroxide, and then a water-soluble carbohydrate, such as molasses, and water sufficient to provide an admixture that is cohesive and plastic. Because of the low water content of the hydraulic cement admixture, products made therefrom have good ultimate properties and can be made by an extrusion process in addition to the conventional molding process.
TL;DR: In this article, the effects of type of cement, initial water:cement ratio, initial porosity, and curing time on the compressive strength of molded cement pastes are described.
TL;DR: In this article, the degree of hydration, the expansion during hydration and the total porosity of low-porosity portland cement pastes were investigated at hydration times ranging from 1 hour to 180 days.
Patent•
27 Nov 1972
TL;DR: In this paper, a modified rapid hardening portland cement of which a setting time is convenient even at low temperature, which comprises mixing calcium carbonates, sodium carbonate, potassium carbonate and/or magnesium carbonate.
Abstract: This invention relates to a process for manufacturing a modified rapid hardening portland cement of which a setting time is convenient even at low temperature, which comprises mixing calcium carbonate, sodium carbonate, potassium carbonate and/or magnesium carbonate, or a mixture of said carbonate and sodium sulfate, potassium sulfate, aluminium sulfate and/or magnesium sulfate with a clinker which mainly consists of a calcium halo-aluminate having the formula 11CaO.7Al2O3.CaX2, intergrinding the mixture and then mixing finely powdered anhydrite with the ground mixture to manufacture cement in an amount such that the weight ratio of Al2O3/SO3 in the cement is 0.6-1.8.
Patent•
04 Aug 1972
TL;DR: In this article, ground mixtures of conventional Portland cement-making components are mixed with relatively small amounts of boron-containing components, and the mixtures are burned at kiln temperatures substantially below those normally utilized to form clinker.
Abstract: Ground mixtures of conventional Portland cement-making components are mixed with relatively small amounts of boron-containing components, and the mixtures are burned at kiln temperatures substantially below those normally utilized to form clinker. The resultant clinker is more easily grindable than that produced in conventional processes of Portland cement production, and the cement resulting from the grinding of the clinker yields cementitious products possessing substantially higher compressive strength than is exhibited by Portland cement made from the same components in the absence of the boron-containing component.
Patent•
30 May 1972
TL;DR: Fast setting hydraulic cement having very high compressive strengths within a few hours of mixing with water, and generally from about 2,900 to over 5,000 p.i.s. as discussed by the authors within 24 hours, containing beta 2CaO.SiO2; 3.3A12O3CaSO4; and chemically unbound CaSO4 obtained by firing at a temperature between about 1,200 and 1,600*C for about 1 to 5 hours a mixture of a source respectively of CaO, SiO2, Al2O3 and SO3
Abstract: Fast setting hydraulic cement having very high compressive strengths within a few hours of mixing with water, and generally from about 2,900 to over 5,000 p.s.i. within 24 hours, containing beta 2CaO.SiO2; 3CaO.3A12O3CaSO4; and chemically unbound CaSO4 obtained by firing at a temperature between about 1,200 and 1,600*C for about 1 to 5 hours a mixture of a source respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1 to 3 moles of CaSO4 to about 0.5 to 2 plus 2n moles of CaCO3 per mole of Al2O3.nSiO2 and grinding the resultant clinker.
Patent•
20 Sep 1972TL;DR: In this article, the additive-water mixture is analyzed continuously on a sample of the mixture in a spectrophotometer, the output signal of which may be displayed on a meter or may be used to control the relative quantities of water and additive that go into the additivewater mixture.
Abstract: A method of cementing oil, gas or water wells and the like, wherein a solution, dispersion, suspension, or the like of a cement additive in water is prepared at a predetermined concentration of additive and is thereafter mixed with dry powdered cement to form a cement slurry, and a sample of the additive-water mixture is analyzed prior to its being mixed with the cement, to verify that the additive-water mixture contains the desired concentration of additive. The analysis of the additive-water mixture preferably is performed continuously on a sample of the mixture in a spectrophotometer, the output signal of which may be displayed on a meter or may be used to control the relative quantities of water and additive that go into the additive-water mixture.
TL;DR: In this article, the authors performed an experimental study on low porosity portland cement pastes of ages between 15 hours and 3 months and found that nitrogen areas and total pore volumes are much smaller than water areas and their changes with paste age are basically different.
TL;DR: In this article, the relationship between strength and the composition and fineness of Portland Cement is investigated using regression analysis and the authors differ in their opinions on the relative importance of C3S and C3A.
TL;DR: In this paper, the vadose and phreatic diagenesis in carbonate rocks have been simulated in the laboratory, using CO2-charged water to leach a "source bed" of carbonate sand.
Abstract: Some processes of vadose and phreatic diagenesis in carbonate rocks have been simulated in the laboratory, using CO2-charged water to leach a "source bed" of carbonate sand. Precipitation of calcite cement in a second sand body, above and below an artificial water table, was induced by CO2 evasion. Magnesian calcite was preferentially leached from the source bed, and calcite was precipitated as cement in the second sand unit. More cement was produced in the "vadose" zone than in the "phreatic" zone. Cement formed in the vadose zone is composed of micron-sized crystals, and occurs as abundant rim cement and grain contact cement. Crystal size increases with distance from grain boundaries. Rounding of intergranular void spaces is common. Cement formed in the phreatic zone is more coarsely crystalline (50 microns) than in the vadose and abuts directly against original skeletal grain boundaries. The texture of the vadose cement closely resembles textures observed in vadose cementation of skeletal calcarenites in Bermuda.
Patent•
23 May 1972TL;DR: In this paper, a hydraulic cement composition comprising a hydraulic fluid in admixture with certain short length fibers is introduced into the unstable earthen formations, particularly subterranean formations, penetrated by holes.
Abstract: Unstable earthen formations, particularly subterranean formations, penetrated by holes are stabilized against cave-in, sloughing, and the like, by introducing into the unstable formation a cement composition comprising a hydraulic cement in admixture with certain short length fibers.
TL;DR: Ten polycarboxylate cement powders have been analysed for their major constituents and have been classified into four main categories, and zinc oxide appears to be the principal component of all the powders.
Journal Article•
TL;DR: In this paper, the dynamic shear modulus and damping characteristics of two soils, a uniform sand and a silty clay, treated with Type 1 portland cement are determined by the resonant column technique.
Abstract: The dynamic shear modulus and damping characteristics of 2 soils, a uniform sand and a silty clay, treated with Type 1 portland cement are determined by the resonant column technique. Test variables studied are cement content, confining pressure, shear-strain amplitude, and moisture content. The dynamic shear modulus and damping of both uniform sand and silty clay can be greatly increased by adding a small amount of cement.
TL;DR: It is suggested that the anionic groups on the matric proteins may serve as sites for nucleation during calcification in cured or solidified barnacle cement.
Abstract: 1. Cured or solidified barnacle cement is predominantly calcium carbonate in a proteinaceous matrix. Calcite was found to be the crystalline form of the calcium carbonate by X-ray analysis. Other mineral elements and chitin were also detected. 2. Protein fractions were isolated from the shell and solidified cement ofBalanus nubilus. Amino acid analyses indicated significant differences in the two fractions, particularly with regard to the glycine content. Both fractions were high in acidic amino acids. 3. Stained thin sections of the solidified cement revealed a laminated array of protein matrices surrounded by calcium carbonate (calcite). It is suggested that the anionic groups on the matric proteins may serve as sites for nucleation during calcification.
Patent•
27 Oct 1972TL;DR: A method for the production of a water-permeable porous concrete comprising the steps of mixing a concrete mixture containing A. GRANULAR MINERAL AGGREGATES OF A UNIFORM GRAIN FRACTION in the RANGE of 3 to 30 mm with a tolerance range of 4 to 15 mm, B. HYDRAULIC CEMENT in the PRESCRIBED AMOUNT ACCORDING to the JOB SPECIFICATIONS, C. WATER in SUCH an AMOUNT that the WATER-CEMENT RATIO
Abstract: A method for the production of a water-permeable porous concrete comprising the steps of mixing a concrete mixture containing A. GRANULAR MINERAL AGGREGATES OF A UNIFORM GRAIN FRACTION IN THE RANGE OF 3 TO 30 MM WITH A TOLERANCE RANGE OF 4 TO 15 MM, B. HYDRAULIC CEMENT IN THE PRESCRIBED AMOUNT ACCORDING TO THE JOB SPECIFICATIONS, C. A MACROMOLECULAR WATER-SOLUBLE COMPOUND IN AN AMOUNT OF FROM 0.05 TO 2 PERCENT BY WEIGHT BASED ON THE CEMENT, SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF PLANT GUMS, STARCH PRODUCTS, CELLULOSE ETHERS, AND SYNTHETIC POLYMERS. D. WATER IN SUCH AN AMOUNT THAT THE WATER-CEMENT RATIO IS BETWEEN 0.32 AND 0.48 WHEREBY SAID CONCRETE MIXTURE IS SPRAYABLE, AND PLACING SAID CONCRETE MIXTURE BY SPRAYING, AS WELL AS THE HARDENED CONCRETE MIXTURE.
Patent•
16 Mar 1972
TL;DR: In this paper, the authors describe the process of controlling the reaction of the exhaust limes to the SULFUR DIOXIDE GAS (SO2) in order to control the setting time of the CEMENT.
Abstract: COMBUSTION GASSES FROM FUEL-BURNING FURNACES ARE TREATED TO SEPARATE SOLID PARTICLES SUCH AS FLY ASH AND TO OXIDIZE THE SULFUR DIOXIDE GAS (SO2) CONTAINED THEREIN TO SULFUR TRIOXIDE (SO3). THE SO3 IS REACTED WITH EXCESS LIME (CAO) TO FORM CALCIUM SULFATE (CASO4). THE CASO4, UNSPENT LIME PARTICLES, SOME OF WHICH HAVE CRACKED OUTER SHELLS OF CASO4, AND COLLECTED FLY ASH ARE PACKAGED DRY AND USED IN APPROPRIATELY BLENDED FORM TOGETHER WITH CEMENT AND SAND, GRAVEL, OR ROCK TO FROM CONSTRUCTION MATERIALS, THE AVERAGE PERCENTAGE OF CASO4 THEREIN BEING REGULATED TO CONTROL THE SETTING TIME OF THE CEMENT. THE PROPORTION OF THE EXCESS LIME IS AUTOMATICALLY REGULATED BY PROCESS-CONTROL DEVICES WHICH CONTINUOUSLY MONITOR AND CONTROL THE REACTION APPLYING THE PARAMETERS OF FUEL COMPOSITIONS, AND SULFUR OXIDE LEVEL IN THE COMBUSTION GASSES.