Compressive Strength Of Cement Research Articles

Hydroxyapatite-Acrylic Acid Copolymer Cement for Dental Applications : Part 1. Compressive, Bending and Tensile Strengths of the Hydroxyapatite Cement

Hydroxyapatite-Acrylic Acid Copolymer Cement for Dental Applications : Part 1. Compressive, Bending and Tensile Strengths of the Hydroxyapatite Cement

Calcareous fillers and the compressive strength of portland cement

The effect of two calcareous fillers (ground limestone and reagent quality CaCO 3) on the compressive strength of Portland cement, was studied and compared with the corresponding effect of two pozzolanic fillers (ground scoria and Rhine trass) and one non-calcareous, non-hydraulic filler (reagent quality CaF 2). It was concluded that fillers affect strength through their accelerating effect on the cement hydration. This effect was found to be essentially the same for all the fillers studied irrespective of their specific chemical composition. It was also concluded that the formation of calcium carboaluminate, if it took place when calcareous fillers were involved, did not necessarily affect the cement compressive strength. Further tests are being carried out to show that the use of fillers is, indeed, associated with an increased rate of hydration.

Cement Bond Log-A Study of Cement and Casing Variables

Abstract Experimental and theoretical studies of casing-borne signals have provided data on the attenuation effect, compressive strength and shear modulus for different types of cement. These data resulted in the establishment of a definite relationship between the cement compressive strength and the Cement Bond log reading. The relationship is influenced by the casing dimensions, but is independent of the type of cement and the curing conditions.The theoretical analysis provides a mathematical statement of the phenomenon and shows that the attenuation rate is basically a function of the shear modulus of the cement and the thickness of the casing. The lab tests provided a connection between the shear modulus and the compressive strength, and permitted a comparison of the experimental and theoretical work.The results of the experimental and theoretical study have provided means of quantitative interpretation of the Cement Bond log. This interpretation is made more convenient with the use of a nomograph. Introduction Past interpretation of Cement Bond logs has been essentially based upon a qualitative comparison between the log response in the zone of interest and the responses in the "fully cemented" and the "uncemented" intervals. Most of the variables influencing the magnitude of the signals were recognized in an earlier paper; however, insufficient laboratory data were available at that time for quantitative evaluation of these variables. Early attempts to use the numerical amplitudes of the signals without full knowledge of their significance resulted in erroneous comparisons between various types of cement. An extensive program was undertaken to evaluate, both experimentally and theoretically, the attenuation phenomenon and to study the effects of the more common variables.A major objective of the experimental program was to obtain data on the relationship between cement-bond-tool response and physical property standards used by the industry so that practical interpretation methods could be devised. The studies included a comparison of attenuation rate with these properties as a function of time, temperature and pressure, using common sizes of casing. The main result was that a definite relationship was established between the compressive strength of the cement in intimate contact with the casing and the response of the cement bond tool. For a given casing thickness, regardless of the type of cement or the curing conditions used, the attenuation rate is a function of the compressive strength.A theoretical analysis showed that the attenuation rate for casing-borne signals should be a function of (among other things) the shear modulus of the cement and the thickness of the casing. The relationship between the compressive strength and shear modulus for curing times similar to those encountered in the field was determined from laboratory tests. Using this relationship, the computed attenuation rates showed reasonable agreement with the measured attenuation rates.The purpose of this paper is to report the results of the experimental and theoretical investigations and to present the first practical method for a quantitative interpretation of Cement Bond logs based on known variables. This method is applicable where the casing-borne signal is not affected by high-velocity formation arrivals. DESCRIPTION OF LOGGING TOOL The Cement Bond logging tool shown schematically in Fig. 1 has been described previously. The tool consists of two sections: acoustic and electronic. The acoustic section contains a transmitter and a receiver, usually spaced 3-ft apart. Sonic energy emitted by the transmitter travels through the casing and is detected at the receiver. JPT P. 545^

Effect of gypsum content on compressive strength of cements

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Effect of electrolysis on the compressive strength of cement and concrete

A paper on “The Electrolytic Corrosion of Reinforced Concrete” by C. E. Magnusson and G. H. Smith was read before the A. I. E. E. June 30, 1911, and, as stated in that paper, the results could not be pronounced entirely conclusive, as the duration of the experiments was only 30 days. In the present paper a similar series of experiments is described by the authors in which the tests were continued for several months. The paper gives in tabular form the result of a large number of experiments and the conclusions corroborate the results reported in the former paper. For the current density covered by the experiments, the current was found to produce no change in the compressive strength of concrete cubes, from which it is deduced that the failures of reinforced concrete due to electrolysis are due entirely to the forces produced by the increase of volume when iron is changed into iron oxide, and not by any direct action of the current upon the concrete.

Effect of Electrolysis on the Compressive Strength of Cement and Concrete

A paper on ``The Electrolytic Corrosion of Reinforced Concrete'', by C.E. Magnusson and G. H. Smith, was read before the A. I. E. E. June 30, 1911, and, as stated in that paper, the results could not be pronounced entirely conclusive, as the duration of the experiments was only 30 days. In the present paper a similar series of experiments is described by the authors in which the tests were continued for several months. The paper gives in tabular form the results of a large number of experiments and the conclusions corroborate the results reported in the former paper. For the current density covered by the experiments, the current was found to produce no change in the compressive strength of concrete cubes, from which it is deduced that the failures of reinforced concrete due to electrolysis are due entirely to the forces produced by the increase of volume when iron is changed into iron oxide, and not by any direct action of the current upon the concrete.

Report of the Committee On the Compressive Strength of Cements and the Compression of Mortars and Settlement of Masonry

In the report made in July last, mention was made of the Watertown experiments, but the results were but partly given, and your Committee propose at this time to discuss them as a whole.

Report of Progress of the Committee on the Compressive Strength of Cements and the Compression of Mortars and Settlement of Masonry

Your Committee have been able to make some progress during the past six months, but not so much as they had hoped, and beg leave to make a partial report and continue their work, deferring a final report until such time as they feel they have accomplished that for which they were appointed. Professor Swain, by the aid of two of his students (Messrs. William C. Cushing and Walter F. Thompson), has extended the experiments upon changes of dimension during induration to our American cements. From an extensive memoir, comprising as well their experiments upon a number of other points foreign to our investigation, we condense the following statement. This was partially reported upon at the annual meeting in January, and we omit the description of apparatus which was then given.

Report of Progress by the Committee on the Compressive Strength of Cements and the Compression of Mortars and Settlement of Masonry

Report of Progress by the Committee on the Compressive Strength of Cements and the Compression of Mortars and Settlement of Masonry