Showing papers on "Cement published in 1980"
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TL;DR: In this article, the basic nature of the cement-aggregate bond and its effect on concrete performance is reviewed, and it is suggested that the quality of the bond affects concrete durability.
105 citations
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TL;DR: In this paper, infrared and Raman spectroscopy has been used for identification of cement phases including different polymorphic and crystal forms, estimation of phases in cement, cement hydration, admixture, concrete-polymer, alkali-aggregate reactions, etc.
103 citations
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04 Dec 1980
TL;DR: In this paper, a method of composite building materials from a mixture of plant fibers bonded with portland cement is described, where plant fibers, cement and soluble silicates in certain proportions are mixed and heated under pressure for a short period to get physically stable product that can be cured under atmospheric conditions to full strength.
Abstract: The specification discloses a method of producing composite building materials from a mixture of plant fibers bonded with portland cement. Plant fibers, cement and soluble silicates in certain proportions are mixed and heated under pressure for a short period to get physically stable product that can be cured under atmospheric conditions to full strength. The plant fibers may initially be pretreated with an aqueous solution containing dichromate or permanganate ion prior to adding the cement to negate the adverse effects of set inhibiting water-soluble compounds in the fiber. Other chemicals may be added to modify the reaction and improve the product.
93 citations
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LGC1
TL;DR: The erosion and water absorption of several glass-ionomer cements, a zinc polycarboxylate cement and a dental silicate cement were compared both in neutral and acid solution and it is shown that the glass-ionic cements are least affected by acid solutions.
87 citations
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01 Sep 1980
TL;DR: In this article, the effect of partially replacing Portland cement with either ground granulated blast-furnace slag or fly ash on the performance of massive concrete pours was investigated.
Abstract: The Paper presents the results of an investigation to monitor the effect of partially replacing Portland cement with either ground granulated blast-furnace slag or fly ash on the performance of massive concrete pours. Temperature and strain were monitored in three pours each 4.5 m deep which form part of the foundations for a grinding mill at the Frodingham Cement Works in Scunthorpe. The total cementitious material content in each pour was 400 kg/m3. In one case 75% of the OPC was replaced by granulated slag and in another, 30% was replaced by fly ash. Strengths were measured under British Standard and temperature matched curing conditions to observe the effect of the in situ heat cycle. To enable a theoretical assessment of thermal stresses at early age to be made, laboratory tests on similar concrete were carried out to determine adiabatic temperature rise, thermal movement, elastic modulus and creep characteristics. Results of the laboratory and site investigations are assessed in relation to existing data.
82 citations
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20 Feb 1980TL;DR: An acrylic cement-like substance which permits seating and securing of a prosthesis into living bone which comprises a mixture of a liquid monomer component and a polymer powder component such that upon mixing the two components, a cement which maintains a low viscosity for a longer period of time is formed.
Abstract: An acrylic cement-like substance which permits seating and securing of a prosthesis into living bone which comprises a mixture of a liquid monomer component and a polymer powder component such that upon mixing the two components, a cement which maintains a low viscosity for a longer period of time is formed. The low viscosity bone cement is intended for syringe or injector gun use only as it is to be used before the cement becomes doughy. This low viscosity bone cement has a viscosity of approximately 20 degrees C. (68 degrees F.), of less than 1500 poise, and preferably less than 1000 poise up to the sixth or seventh minute after the two components are mixed. The cement used in the lower viscosity state is more capable of penetrating the trabeculae of bones when used to secure a prosthesis, than when the cement is applied in the doughy state.
77 citations
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TL;DR: In this article, the effects of age and water/cement ratio on the products of hydration of cement paste are quantified as weight losses related to five separate peaks isolated by means of the semi-isothermal method of differential thermogravimetry.
72 citations
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05 Aug 1980TL;DR: In this article, a mixing component for preparing the final cement mixture is either a liquid mixing component comprising an aqueous solution of a certain maleic acid-acrylic acid-copolymer and optionally usual additives or a solid, powdery mixing component consisting a powder mixture of a glass ionomer cement powder and the maleic acids-acric acrylic acid copolymer in solid form.
Abstract: Dental glass ionomer cements are obtained by using as a mixing component for preparing the final cement mixture either a liquid mixing component comprising an aqueous solution of a certain maleic acid-acrylic acid-copolymer and optionally usual additives or a solid, powdery mixing component comprising a powder mixture of a glass ionomer cement powder and the maleic acid-acrylic acid-copolymer in solid form and optionally usual additives.
67 citations
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23 Apr 1980TL;DR: In this paper, an improved material for thermal insulation of building structures such as residential housing is presented. The material comprises an inorganic, low-density cellular thermally insulating foam comprising a gypsum matrix having minute cavities homogeneously distributed therein.
Abstract: An improved material particularly suited for the thermal insulation of building structures such as residential housing. The material comprises an inorganic, low-density cellular thermally insulating foam comprising a gypsum matrix having minute cavities homogeneously distributed therein. The material has a dry density of less than about 6 pounds per cubic foot and a thermal coefficient of less than about 0.37. The gypsum matrix includes therein approximately 1 to 15% by weight of cement, approximately 0.5 to 7% by weight of mineral wool and at least approximately 0.25% by weight of chopped glass.
66 citations
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14 Jan 1980
TL;DR: A high temperature, curable cement which is characterized in the cured state by a hydrothermally crystallized phase of diopside and/or serpentine is described in this article.
Abstract: A high temperature, curable cement which is characterized in the cured state by a hydrothermally crystallized phase of diopside and/or serpentine.
64 citations
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TL;DR: The effect of sulfonated naphthalene- and melamine-formaline condensates upon the viscometric properties of cement pastes and slurries has been investigated as discussed by the authors.
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15 Jul 1980
TL;DR: A powder of a slag formed at the time of manufacturing steel is used to remove heavy metals contained in waste water as mentioned in this paper, and the slag may be heated to recover the heavy metals adsorbed thereby or the used slag can be formed into solid blocks, ballast or aggregate by admixing with Portland cement or alumina cement.
Abstract: A powder of a slag formed at the time of manufacturing steel is used to remove heavy metals contained in waste water. After the use the slag may be heated to recover the heavy metals adsorbed thereby or the used slag may be formed into solid blocks, ballast or aggregate by admixing with Portland cement or alumina cement.
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TL;DR: Tensile bond strengths and residual cement on metal coverage data indicated that, for each metal system, interfaces created prior to and at the onset of the Dough stage formed superior interfaces for implantation compared to those formed late in the dough stage.
Abstract: Interfaces were formed between acrylic bone cement and three commonly used surgical alloys (316L SS, Co-Cr-Mo, and Ti-6A1-4V), in an attempt to further define cementation parameters of acrylic bone cement for use in orthopaedic surgery. Metal/cement interfaces were made at three distinct times during the setting cycle of the cement and were cured for 1 hr, 1 day, and 1 week. The metals were prepared with roughly polished or finely polished prepassivated surfaces. Tensile bond strengths and residual cement on metal coverage data indicated that, for each metal system, interfaces created prior to and at the onset of the dough stage formed superior interfaces for implantation compared to those formed late in the dough stage. Furthermore, electropolishing plus prepassivation offered a more efficient bonding surface than mechanical polishing.
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TL;DR: In vitro apparatus is described which simulates conditions in the acetabulum during the Charnley-Muller type low friction arthroplasty procedure, providing a direct measurement of the temperature history of the surface where the bone would be in contact, and data indicate that the temperature at the bone-cement interface is linearly dependent on local cement thickness.
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30 May 1980
TL;DR: In this paper, a process for producing a binder (cement) to be used in slurry, mortar, or concrete having a low water-to-cement ratio is described.
Abstract: A process for producing a binder (cement) to be used in slurry, mortar, or concrete having a low water-to-cement ratio. As raw-material for the binder is used at least 50% by weight of a hydraulic material, such as slag, technical pozzolanas and/or natural pozzolanas. The hydraulic material is ground to a specific surface of at least 400 m 2 /kg. To the raw-material is added 0.1 to 5% by weight of a plasticizing material, such as a sulphonated polyelectrolyte. To the raw-material are also added in total 0.5 to 8% by weight of sodium carbonate and/or sodium hydroxide. Added in small amounts, the sodium carbonate and the sodium hydroxide, separately or in combination, considerably shorten the hardening time of the concrete, yield excellent strengths, and make it possible to use cheap raw-materials.
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TL;DR: In this article, three hundred sixty-five particles of C-S-H, Ca(OH)2, AFm phase, and AFt phase from pastes of normally ground portland cements and of finely ground cements, clinkers were analyzed.
Abstract: Three hundred sixty-five particles of C-S-H, Ca(OH)2, AFm phase, and AFt phase from pastes of normally ground portland cements and of finely ground cements and clinkers were analyzed. All the phases, except the Ca(OH)2, showed significant variation in composition among paste specimens and among particles within each specimen. The C-S-H contains significant amounts of Al, Fe, and S; for that of a normally ground portland cement paste, cured for 28 days, the median Si:AI, Si:Fe, and Si:S ratios were 11, 43, and 15, respectively, whereas the mean Ca:Si ratio for all the particles analyzed was 2.0. The AFm phase in cement pastes is not pure monosulfate but has a mixture of sulfate, hydroxide, and Al- and Si-bearing ions in its interlayer sites; the AFt phase is not pure ettringite but contains Si and its sulfate is probably partly replaced by hydroxide. The Al and Fe contents in the C-S-H and the Si contents in the AFm and AFt phases are greater when finely ground starting materials are used. This fact, together with the marked variation among particles, emphasizes the difficulty of ionic transport in cement pastes.
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TL;DR: In this paper, an analogy between the process of membrane formation and osmosis in "silicate gardens" and Portland cement hydration is discussed, where the major similarity is considered to be the formation of solids at a fluid interface at which the local supersaturation is high so that colloidal solids having no long-range order are produced.
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24 Jan 1980TL;DR: In this article, the authors provided a mixture of water, a metal halide or sulfate selected from the group consisting of magnesium, aluminum and zinc halides and sulfates, and a metal oxides and carbonates from the groups consisting of calcium and barium carbonates.
Abstract: Cement compositions which upon curing have high compressive strengths and are rapidly dissolved in acids are provided comprised of water, a metal halide or sulfate selected from the group consisting of magnesium, aluminum and zinc halides and sulfates, a metal oxide selected from the group consisting of magnesium, aluminum and zinc oxides and a metal carbonate selected from the group consisting of calcium and barium carbonates. Methods of using the cement compositions are also provided.
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05 Jun 1980TL;DR: In this article, a column of cement slurry is placed in the annulus and allowed to set, such that the amount of gas contained in the slurry and the set cement increases with increasing depth.
Abstract: To cement the annulus around a casing string in a well penetrating an underground formation, a column of cement slurry which is or includes a foam cement slurry is placed in the annulus and allowed to set. The amount of gas contained in the slurry and the set cement is such that the density in the cement slurry column and the cement in the annulus increases with increasing depth.
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21 May 1980
TL;DR: In this article, the authors present a method for incorporating crystalline calcium carbonate, preferably in the form of powdered marble, with the normal constituents to dilute the relative amounts of these constituents and thus make a more economic blend without substantial degradation to the physical characteristics of the article of manufacture.
Abstract: The present invention relates to hydrothermally cured articles of manufacture and the processes for making the same. In the past, calcium carbonate has been included in such articles and processes a number inert filler materials to alter physical characteristics, appearance, etc. The present invention comprises incorporating crystalline calcium carbonate, preferably in the form of powdered marble, with the normal constituents to dilute the relative amounts of these constituents and thus make a more economic blend without substantial degradation to the physical characteristics of the article of manufacture incorporating such crystalline calcium carbonate.
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17 Jun 1980
TL;DR: In this paper, a method for disposing of spent residue from a fluidized combustion bed of the type in which lime or limestone particles are suspended in a fluidised medium and a carbonaceous fuel is ignited proximate said fluidized medium to capture substantial amounts of SOx which is generated upon ignition of said carbonaceous fuels, the lime component of which has been substantially hydrated by mixing with water, and pozzolanic material such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix.
Abstract: A method, wherein spent residue from a fluidized combustion bed of the type in which lime or limestone particles are suspended in a fluidized medium and a carbonaceous fuel is ignited proximate said fluidized medium to capture therein substantial amounts of SOx which is generated upon ignition of said carbonaceous fuel, the lime component of which has been substantially hydrated by mixing with water, and pozzolanic material, such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix. The mix is cast into desired shape and cured. If desired, the shape may then be crushed so as to result in a fluidized bed combustion residue-fly ash aggregate material or the shape may be used by itself. The method enables a commercially acceptable way of disposing of the spent bed residue by incorporation thereof in a high-strength concrete-like material.
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17 Jun 1980TL;DR: In this article, a hydraulic cement composition comprising a mixture of at least one particulate hydraulic cement and water in which the weight average mean particle size of the particles of the cement is less than 20 microns and the proportion of water is not greater than 30% by weight of the hydraulic cement in the composition is defined.
Abstract: A hydraulic cement composition comprising a mixture of at least one particulate hydraulic cement and water in which the weight average mean particle size of the particles of the cement is less than 20 microns and in which the proportion of water is not greater than 30% by weight of the hydraulic cement in the composition, the cement being preferably substantially free of particles having a size above 20 microns and the proportion of water being preferably not greater than 20% by weight.
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TL;DR: In this paper, the effects of sulfonated naphthalene- and melamine-formaline condensates upon the rheologic properties of cement pastes and slurries have been investigated.
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TL;DR: In this paper, it was found that Portland cements containing boro- and citro-gypsum produced considerably more ettringite than those with desulpho-and natural gypsum.
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TL;DR: In this paper, the leaching of Ra-226 from U mill tailings consolidated with cement and cement plus clay and/or peat was described by a plane source diffusion model or a simultaneous first order reaction and diffusion model.
Abstract: The leaching of Ra-226 from U mill tailings consolidated with cement and cement plus clay and/or peat may be described by a plane source diffusion model or a simultaneous first order reaction and diffusion model. A useful quantitative measure of the effectiveness of the consolidation process is the magnitude of the effective diffusion coefficient relative to that of the unconsolidated tailings material. The lowest effective diffusion coefficient upon consolidation was for consolidation with cement and peat.
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TL;DR: In this paper, the development of glass fibre compositions having sufficient alkali resistance to provide useful reinforcement in Portland cement and, at the same time, being capable of commercial scale fibrizing is described.
Abstract: The development of glass fibre compositions having sufficient alkali resistance to provide useful reinforcement in Portland cement and, at the same time, being capable of commercial scale fibrizing, is described. Chemical tests for alkali resistance were used in an initial evaluation of glass compositions, which were then further assessed by strength retention measurements in alkaline solutions and in cement. The different types of tests gave different results in some instances and indicated the need for thorough and wide ranging assessment techniques when evaluating and proving glass fibres for cement reinforcement.
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22 Feb 1980TL;DR: In this article, a concrete which is capable of inhibiting corrosion of metal pieces contained therein or in contact therewith comprising a high strength concrete formed from hydraulic cement and containing at least about 2 percent Ca(NO 2 ) 2 therein was proposed.
Abstract: This invention is directed to a concrete which is capable of inhibiting corrosion of metal pieces contained therein or in contact therewith comprising a high strength concrete formed from hydraulic cement and containing at least about 2 percent Ca(NO 2 ) 2 therein.
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26 Mar 1980TL;DR: In this paper, the quantity of water on the surface of sand particles is reduced by applying an impact force, e.g., the centrifugal force created by a rotating disc.
Abstract: The quantity of water on the surface of sand particles is reduced by applying an impact force, e.g. centrifugal force created by a rotating disc. The sand particles thus treated are especially suitable for preparing a green concrete compound or a cement mortar by mixing them with water, gravel and cement.
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12 Feb 1980
TL;DR: In this paper, a pozzolan material, fine aggregate, air, water, at least one alkali metal constituent selected from the group consisting of sodium, potassium, and lithium ions, and at least 1 anionic constituent which is capable of forming complexes with ferric ions, is soluble in water, and forms a calcium salt which is also water soluble.
Abstract: A cement composition comprising cement, a pozzolan material, fine aggregate, air, water, at least one alkali metal constituent selected from the group consisting of sodium, potassium, and lithium ions, and at least one anionic constituent which is capable of forming complexes with ferric ions, is soluble in water, and forms a calcium salt which is also water soluble, wherein the alkali metal constituent is present in an amount up to approximately 4.0 percent by weight, in terms of the equivalent weight of sodium ions, of the pozzolan material; the anionic constituent is present in an amount up to approximately 6.0 percent by weight, in terms of the equivalent weight of chloride ions, of the pozzolan material; and the cement composition is further characterized by: (a) having a solid volume ratio of cement to the pozzolan material within the range of approximately 0.05 to 2.0; (b) having a ratio of the volume of paste (fly ash, cement, air, and water) to the solid volume of sand within the range of approximately 0.75 to 2.5; and (c) having a ratio of the solid volume of cement to the volume of mortar less than about 0.19. The cement composition of the present invention is substantially less expensive than cement compositions presently employed in the industry having equivalent compressive strengths.
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25 Aug 1980
TL;DR: A quick setting cementitious composition with good early strength characteristics contains, by volume, 1-30% of a cement mixture including Portland Cement, calcium aluminate and calcium sulphate, 0.001-5% of clay and water in excess of 65% as mentioned in this paper.
Abstract: A quick setting cementitious composition with good early strength characteristics contains, by volume, 1-30% of a cement mixture including Portland Cement, calcium aluminate and calcium sulphate, 0.001-5% of clay and water in excess of 65%. The composition is especially suited for filling cavities in underground mines, for the construction of roadside packs, and the various components of the composition can be separately pumped or otherwise conveyed to the cavity.