bluuebunny/crossref_metadata_2025_split huggingface dataset:
Introduction to Symposium on Polymer-Modified Concrete and Mortars: Building on the Past and Moving into the Future
Authors: Bright RP , Fitzgerald PL , O'Brien MJ 
Published: January 2010

Abstract
The following six papers were presented as a part of a symposium on “Polymer-Modified Concrete and Mortars: Building on the Past and Moving into the Future.” The symposium was held on 20 June 1995 in Denver, Colorado and sponsored by ASTM Committee C-9 on Concrete and Aggregates and its Subcommittee C09.14 on Polymer-Modified Concrete and Mortars.
Curing Stresses in Polymer-Modified Repair Mortars
Authors: Pinelle DJ 
Published: January 2010

Abstract
Accurate correlation between standard test results and observed field performance of repair mortars has been difficult to achieve. A study was conducted in an attempt to understand the development of physical properties and induced tensile stresses as a repair material cures and how these affect the likelihood of early age cracking. A mathematical model was developed to predict when induced stresses may be sufficient to crack a repair mortar while curing. Using this technique, the influence of two polymers on a generic mortar was investigated in the laboratory. The laboratory study included measurements over time of tensile strength, drying shrinkage, tensile modulus of elasticity, and tensile creep. The model's predictions were checked by placing the studied mortars in a simulated repair situation.
The influence of polymers on physical properties, the stress developed while curing, and field performance were studied. Results suggest that the type of polymer has an important effect on properties, such as tensile creep and modulus of elasticity. The data also indicate a balance of certain properties is needed in order to make a repair mortar more resistant to cracking. Further, since these properties change as the material cures, their relationship over time must be understood.
The test procedures, mathematical model, and results are discussed in this paper. Cross references to a simulated field installation is also included.
Self-Smoothing Industrial Floors
Authors: Alexanderson J 
Published: January 2010

Abstract
Self-smoothing industrial floors have been developed in Sweden over the last 15 years.
In the beginning, the binder was portland cement, but later, high-alumina cement systems have taken over due to several reasons. Also the polymers have changed from acrylic dispersions in the early industrial floors to dispersible powders based on ethylene vinylacetate copolymers today. The dominating plasticizer in the early underlayment products was casein, but due to serious problems it has been changed to melamine-based superplasticizers.
The load-bearing properties are tested with a rolling wheel test that is more relevant than compressive strength. The polymer modification increases the performance quite substantially.
The machine systems have developed considerably over the years. In the beginning, small batch mixers and pumps were used, whereas today trucks with complete equipment can deliver the material ready-mixed on site with quite high capacity.
Field experience is positive and the use of self-smoothing floors is expected to grow.
Comparison of Liquid Dispersions with Spray-Dried Acrylic Polymers as Modifiers of a Cement-Based Patching Material
Authors: Bright RP 
Published: January 2010

Abstract
This study was carried out to compare the performance of dry polymers to the more conventional liquid-based polymers in a general purpose patching mortar. A series of polymer-modified mortars were thus evaluated, comparing two spray-dried redispersible acrylic powders with two water-based polymers: an acrylic dispersion and a styrene-butadiene rubber dispersion.
The results of the testing showed that the use of the redispersible powders resulted in mortars with excellent adhesion and strength properties comparable to the liquid product. The mortars modified with these dry polymers also exhibited slightly higher shrinkage than the dispersions. However, combined with their advantages over liquid product, such as ease of shipping and handling, the dry polymers are very suitable for use in the formulation of high-performance patching materials.
Performance and Correlation of the Properties of Fly Ash Cement Concrete
Authors: Al-Amoudi OSB , Maslehuddin M , Asi IM 
Published: January 2010

Abstract
This investigation was conducted to evaluate the performance of fly ash cement concrete specimens made by cement replacement levels of 0, 10, 20, 30, and 40% with Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Concrete (ASTM C 618) Class F fly ash. Compressive strength, pulse velocity, porosity, and water permeability were determined after 28, 90, 180, and 360 days of water curing. Reinforced concrete specimens were used to assess the corrosion-resistance of plain and fly ash cement concretes in chloride environments. The corrosion potentials on steel were measured at periodic intervals to determine the time-to-initiation of reinforcement corrosion. The data generated was statistically analyzed to ascertain the relationship between the various properties of plain and fly ash cement concretes.
Results indicated a better performance by the 20% fly ash cement concrete than plain cement concrete and those made with other cement replacement levels. A good correlation between porosity, compressive strength, permeability, and porosity was observed.
A Possible Method for Identifying Fly Ashes That Will Improve the Sulfate Resistance of Concretes
Authors: Dunstan ER 
Published: January 2010

Abstract
Current methods for determining sulfate resistance of fly ash concrete often require several years of testing. An accepted method that can be used to predict sulfate resistance in a few days does not exist. A hypothesis is submitted as a possible step towards development of a comprehensive theory. The sulfate reactivity of fly ash is characterized by its chemical composition. One high calcium fly ash was shown to react similarly to blast-furnace slags. Sulfate resistance of comparable fly ash concretes is shown to correlate with ash composition; therefore, based on chemical composition of fly ash, a sulfate resistance factor R is proposed. The factor is the ratio (C-5)/F, where C is calcium oxide and F is ferric oxide in percent. When R is less than 1.5, a fly ash should improve the sulfate resistance.
An Analytical Approach to Gap-Graded Concrete
Authors: Ehrenburg DO 
Published: January 2010

Abstract
In the mix proportioning process, the concept of minimum voids and the principle of minimum surface area are basically in conflict with each other. The former implies that a blend of several fractions of coarse aggregate is always superior to a single fraction. The latter states that for a given maximum size of aggregate a single fraction is superior to any blend. Between the two extremes—continuous gradation, on the one hand, and a single fraction of coarse aggregate, on the other—lies the vast and largely unexplored gray area of gap-graded mixes. In spite of the great variety of gradation patterns available in this area, certain general principles can be delineated and translated into a system of mix proportioning that is applicable to the total spectrum of concrete mixes.
Formula for Calculating Spacing Factor for Entrained Air Voids
Authors: Walker HN 
Published: January 2010

Abstract
A spacing factor only for small voids is derived from the proportion of small voids to total voids. The formula can be used with any method of air determination in hardened concrete that includes denominating some voids as large and some as small. The formula is not dependent on the size criterion used. A graphic method of estimating the spacing factors is given: ¯L for total voids and ¯Ls for the proportion of small voids.
Concrete Polymer Materials as Alternative Construction Materials for Geothermal Applications—Field Evaluations
Authors: Fontana JJ , Zeldin A 
Published: January 2010

Abstract
A serious problem in the development of geothermal energy is that suitable, durable, and economical construction materials are not readily available. Hot brine and other aerated geothermal fluids are highly corrosive and attack most conventional construction materials. Brookhaven National Laboratory has been investigating the use of concrete polymer materials as alternative construction materials for geothermal processes. To date, successful field tests have been demonstrated at the Geyesers, the U.S. Bureau of Mines Corrosion Facility, and the East Mesa Geothermal Facility. This report is a survey of field and laboratory evaluations of concrete polymer materials that have been shown to be durable and economical as alternative construction materials.
Quick Determination of Cement Properties Through the Use of Hot-Pressing
Authors: Gouda GR , Roy DM 
Published: January 2010

Abstract
By proper application of heat and pressure to a cement paste having a very low water/cement ratio W/C, a hard, strong, dense cylindrical specimen is formed in a very short time. Specimen preparation is simple and only a few grams of cement are required. Compression and splitting (modified tension) tests can be performed and the soundness of the cement can be predicted. Temperature, pressure, time, W/C, sample size, and cement fineness are the parameters that affect the degree of strength. With standardization of the hot-pressing parameters, the physical properties of the cement paste can be obtained quickly instead of after the usual waiting period of from one to four weeks.
Alkali-Silica Reactivity: Some Reconsiderations
Authors: Stark D 
Published: January 2010

Abstract
Numerous instances have been recorded where the use of low alkali cement with certain volcanic aggregates has failed to prevent deleterious alkali-silica reactivity. Present testing using the ASTM Test for Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-Bar Method) (C 227) may fail to identify this reactivity because testing is normally done with only high alkali cements. It is recommended that concurrent testing be done, using a range of both high and low alkali cements, to determine that maximum safe cement alkali level for each aggregate in question. Although the traditional limit of 0.60% alkali has prevented alkali aggregate reaction with many reactive aggregates, there are certain volcanic aggregates that require even lower alkali or the use of suitable pozzolanic materials to avoid alkali aggregate reactivity or both.
Influence of Water-Reducing Admixtures on Properties of Cement Paste—A Miniature Slump Test
Authors: Kantro DL 
Published: January 2010

Abstract
A miniature slump test has been developed for the evaluation of the influence of water-reducing admixtures on the workability of neat portland cement pastes. Resulting paste pat areas rather than heights are measured, and the results are expressed as the percentage of water reduction. Relative effects of various admixtures on a portland cement are illustrated, and influences of specific admixtures on different cements are also shown. Effects of different superwater-reducing admixtures and combinations of ordinary and superwater-reducing admixtures are compared. The mini-slump method has also been used for the evaluation of the loss of workability (slump loss) with time for various admixtures and admixture combinations. The simplicity of the method facilitates accurate and effective evaluation of water-reducing admixtures.
Relative Resistance of Rained-On Concrete Pavements to Abrasion, Skidding, and Scaling
Authors: Dahir SH 
Published: January 2010

Abstract
Cores from concrete pavements that had been exposed to rain while plastic and specimens prepared in the laboratory and exposed to artificial rain showers were tested for abrasion, skid resistance, and scaling. Companion not-rained-on cores and laboratory specimens were similarly tested. The results indicated that average skid resistance measured with the British Pendulum Tester (BPT) was similar on both rained-on and not-rained-on cores and specimens. Full-scale tire skid numbers were about 10% higher on not-rained-on untraveled pavement sections than on adjacent rained-on sections. Scaling caused by freeze-thaw exposure and abrasion loss determined with the U.S. Corps of Engineers Method of Test for Resistance of Concrete or Mortar Surfaces to Abrasion (Procedure CRD-C52-54) were consistently higher on rained-on than on comparable not-rained-on cores and specimens. Abrasion loss was higher on untraveled pavements than on those that had been in use for several years. Also, abrasion loss was higher on specimens that had been exposed to heavier rain intensity, longer rain duration, and deeper texturing.
Comparison of abrasion loss, scaling caused by freeze-thaw exposure, and frictional BPT numbers on not-rained-on and rained-on cores from untraveled pavements and on similarly prepared specimens indicates that abrasion and British Pendulum Numbers can be predetermined from specimens made and tested in the laboratory. Examination of two field sections after exposure to traffic and weathering for two years confirmed the validity of laboratory testing predictions. Two abrasion machines made to the specifications of the U.S. Corps of Engineers Procedure CRD-C52-54 gave two different levels of abrasion loss on paired specimens, but the resulting trends were similar.
Condition of Concrete in Martin Dam After 50 Years of Service
Authors: Mather K 
Published: January 2010

Abstract
The concrete in Martin Dam, an arch-gravity hydroelectric power dam in Alabama, completed in 1926, was sampled by three 152-mm (6-in.) cores drilled in the crest of the dam to the foundation. Samples taken from these cores were examined petrographically, tested ultrasonically to measure compressional- and shear-wave velocities, tested in unconfined compression, tested in triaxial loading in groups of three cores each at three confining pressures, and tested for strength in direct tension.
The petrographic examination yielded evidence of the occurrence of alkali-silica reaction in concrete from all three drill holes; however, alkali-silica reaction gel was not found in the lower part of one hole. The core from this zone contained large flakes of tetracalcium aluminate monosulfate-12-hydrate (C4 A¯SH12). No reference to the presence of this compound in concrete in crystals large enough to be visible to the naked eye was found in the literature. Although the evidence of alkali-silica reaction is clear, it did not extend to cracks in the mortar except to a minor extent. The mechanical tests indicated concrete in good physical condition. Despite the presence of alkali-silica reaction, the Martin Dam concrete appears to be in acceptable condition and in better condition than some younger structures that are still in service.
Inertial Effects in the Instrumented Impact Testing of Cementitious Composites
Authors: Suaris W , Shah SP 
Published: January 2010

Abstract
The effects of specimen inertia on the instrumented impact testing of cementitious composites are discussed and a method for reducing such effects is proposed. A two degree of freedom model capable of predicting the amplitude and period of inertial loading oscillations on the tup-load versus time-trace is presented. Results of tests conducted on asbestos cement and fiber-reinforced concrete are presented and are compared with those predicted using the analytical model. It is concluded that the model developed is satisfactory in predicting inertial loading effects.
Mechanical Properties and Freezing and Thawing Resistance of Non-Air-Entrained, Air-Entrained, and Air-Entrained Superplasticized Concrete Using ASTM Test C 666, Procedures A and B
Authors: Malhotra VM 
Published: January 2010

Abstract
This investigation was undertaken to develop data on the durability of non-air-entrained, air-entrained, and air-entrained superplasticized concrete when tested in accordance with the ASTM Test for Resistance of Concrete to Rapid Freezing and Thawing (C 666) Procedures A and B. A total of nineteen 0.06-m3 mixes were made with water-to-cement ratios ranging from 0.35 to 0.70. Apart from the control mixes, all other mixes were either air-entrained or air-entrained and superplasticized. A number of test prisms were cast and subjected to repeated cycles of freezing and thawing and air-void parameters of the hardened concrete were determined. The following conclusions were made from the test results.
1. Regardless of the test procedures used, the test prisms cast from non-air-entrained concrete disintegrated at less than 31 cycles. The only exceptions were the test prisms cast from concrete with a water-to-cement ratio of 0.35, which indicated satisfactory resistance to repeated cycles of freezing and thawing in test Procedure B, the durability factor after 300 cycles being greater than 90.
2. Regardless of the test procedure used, the concrete prisms cast from air-entrained concrete and air-entrained superplasticized concrete performed satisfactorily when subjected to repeated cycles of freezing and thawing. At the end of 300 cycles, the durability factors were greater than 90. This was in spite of the fact that the bubble spacing factor ¯L for air-entrained superplasticized concrete was, in some instances, greater than 0.20 mm.
Effect of Different Types of Crushers on Shape and Roughness of Aggregates
Authors: Czarnecka ET , Gillott JE 
Published: January 2010

Abstract
The shape and texture of four specimens of crushed aggregates produced by different commercial crushers were quantitatively investigated using the modified Fourier method described in earlier articles. Specimens were classified according to size (all in the range 4 to 64 mm) and type of crusher. Results show that on average the shape of different specimens of crushed aggregates vary more than their surface texture; hence, shape is the dominant factor contributing to the total roughness that combines both characteristics. Particles crushed by a jaw crusher are much more elongated and rectangular than particles that passed through a cone crusher, impactor, or rod mill. The total roughness and shape factor of crushed particles decrease in the order: jaw crusher, cone, impactor, and rod mill. Data provided by the modified Fourier technique give more precise shape as well as textural data that could lead to better control of the aggregates' characteristics; shape and texture have an important bearing upon performance of concrete.
Precision of the Proposed Test Method to Measure Slag Hydraulic Properties
Authors: Lesniak TW 
Published: January 2010

Abstract
A method has been developed which tests the hydraulic properties of finely ground blast furnace slag. Results from round robin testing were analyzed according to the ASTM Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods for Construction Materials (C 802). Evaluation of the data has confirmed the validity of the test method and appropriate precision statements have been developed.
Precision of Flexural Strength and Toughness Parameters for Steel Fiber Reinforced Concrete
Authors: Johnston CD 
Published: January 2010

Abstract
The variability of parameters used to define the toughness of fiber reinforced concrete under static flexural loading is examined to establish the precision statistics needed for ASTM standards dealing with toughness measurement. Included in the anlaysis of single-operator precision are first-crack strength, deflection, and toughness, the toughness index recommended by the American Concrete Institute Committee 544, and a number of other toughness indices that have been shown in a previous paper to define flexural toughness more completely. The single-operator 1S% value defined according to ASTM Standard Practice for Preparing Precision Statements for Test Methods for Construction Materials (C 670) is used as the measure of precision throughout, the bulk of the data being obtained from testing of 300- by 100- by 100-mm (12- by 4- by 4-in.) steel fiber reinforced beams under third-point loading. However, the effects of beam size, shape, span, and mode of loading on both the actual values of the toughness indices and their variability are also discussed. Single-operator levels of precision achievable in flexural toughness tests by an experienced operator using good equipment are summarized to provide input to precision statements for a future ASTM standard dealing with the measurement of flexural toughness under static loading.
Development of a Conductivity Probe to Monitor Setting Time and Moisture Movement in Concrete
Authors: Sriravindrarajah R , Swamy RN 
Published: January 2010

Abstract
The development of a three-dimensional conductivity probe, based on the measurement of electrical conductance between electrodes, to evaluate the setting time of fresh concrete and the variation of moisture content with time in hardened concrete is reported. The construction and calibration of the conductivity probe are described, and a calibration curve translating electrical conductance measurements into available moisture content is presented. Tests are then reported to evaluate the setting time of fresh concrete, and these are related to internal temperature variations. These tests are then extended to study moisture variations in hardened concrete under load and no-load conditions in both sealed and unsealed environments. These measurements taken for up to two years are related to internal humidity measurements. The results show that the conductivity probe is a simple and inexpensive device that gives quantitative information in any direction and possesses qualities of accuracy, reliability, long-term stability, and local resolution.
Accurate Rapid Analysis of Alkali Contents in Portland Cement
Authors: Syal SK , Kataria SS 
Published: January 2010

Abstract
Alkali contents of portland cement/clinker significantly affect the hydration reaction rate and the development of mechanical strength of cements. An accurate, rapid method has been developed for the quantitative determination of alkalies sodium oxide and potassium oxide by use of the flame photometric emission spectroscopic technique. The procedure is free from errors caused by the presence of calcium atoms and the mutual disturbance caused by the different ionization behavior of sodium and potassium salts in the flame. The determinations have been performed in a nitric acid medium with use of optimum amounts of aluminum sulfate and cesium sulfate as the controlling electrolytes. A combination of 2000 ppm of alumina +30 ppm of cesium is optimum for the analysis of ordinary portland cements and clinkers. In the procedure a wide range of alkali concentration is covered by the analysis of solutions for 1 to 10 ppm of sodium oxide and potassium oxide with the best reproducibility in the range of 4 to 8 ppm. The accuracy of the determinations is better than 0.01 ppm. The method is suitable for laboratory analysis as well as for on-line quality control determinations of alkali content.