bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Blast-Furnace Slag Cement
Authors: Cattaneo A , Frigione G 
Published: January 2010

Abstract
The sulfate resisting portland cement is obtained from a special portland cement clinker with low-tricalcium-aluminate content. In Western Europe another cement is used more for constructions in sulfate environments than portland low-tricalcium-aluminate cement, the blast furnace slag cement with slag content higher than 70%. According to ASTM standard Specification for Concrete Aggregates (C 33), when reactive alkali-aggregates are used, portland low-alkali cement is recommended. According to the European experience, the blast-furnace slag cement with slag content greater than 70% does not produce any expansion when used with stone materials of potential alkaline reactivity. This paper deals with the performances of blastfurnace slag cements tested for sulfate resistance and for alkali-aggregates reaction. The results obtained fully confirm the possibility of overcoming the risk of alkali-aggregate expansion and sulfate destruction by using blast furnace slag cements with high-slag content. The lower energy cost of blast-furnace slag cement, which can replace the special portland cement with low-tricalcium aluminate and low-alkali content, may favor its use.
Microcracking and Definition of Failure of High- and Normal-Strength Concretes
Authors: Carrasquillo RL , Slate FO 
Published: January 2010

Abstract
The discontinuity point is defined as that point at which an unstable progressive crack growth mechanism develops in the concrete. A criterion for defining the discontinuity point in terms of microcracking and thus for determining the stress or strain corresponding to the discontinuity point is perhaps the most relevant strength criterion for engineering design because it can identify the onset of failure when a given concrete can no longer withstand a given state of stress without unstable disruption of the structure. This paper summarizes the work done at Cornell University on the development of a criterion for determining stress and strain at discontinuity for different-strength concretes based on the observed internal microcracking at different load stages and proposes ranges of stress and strain at discontinuity for those different concretes.
Quantitative X-Ray Diffraction Analysis of Cement and Clinker: A Bibliography
Authors: Struble LJ 
Published: January 2010

Abstract
This comprehensive bibliography covers analysis of portland cement and concrete by quantitative X-ray diffraction. The citation and an abstract is provided for each reference. The bibliography was prepared at the request of the quantitative X-ray diffraction analysis task group of ASTM Subcommittee C01.23.
Lithological Characteristics of Concrete Aggregates as Related to Durability
Authors: Robinson RF 
Published: January 2010

Abstract
Popouts in concrete bridge decks prompted an investigation into the reasons for such performance in relatively new construction projects. Certain stones usually reddish in color and belonging to a lithologic unit referred to as the superior group appeared to be responsible for the popout action. Conventional tests had not revealed any excessive values or unusual properties. Several area pits were examined, sampled, and tested by different methods. There were no specific series of tests that indicated the durability of aggregates used in this study, but an indication of high absorption to greater loss in soundness tests was detected. From testing results and past performance records, a recommendation was made to require individual stone counts to isolate the amount of the suspect aggregate. It was further recommended that a soundness loss of not more than 5% of the total specimen be allowed to conform with the “deleterious substances” section 501.3.6.4.3 of the current specification.
Some Opportunities to Offset Poor Quality Characteristics of High-Alkali Cement
Authors: Spellman LU 
Published: January 2010

Abstract
It is to be expected that the influx of preheater/precalciner technology will result in a general increase in portland cement alkali level. High-alkali cement is associated, in general, with rapid early strength development and disproportionately lower 28 day strength in mortar cubes in accordance with ASTM Compressive Strength of Hydraulic Cement Mortars (C 109). Too, alkali cements react more readily with reactive aggregates. While portland cements tend to be increasing in alkali content, sources of unreactive aggregates tend to be decreasing.
The literature suggests that the use of fly ash can mollify the reaction of alkalies in both strength development and in alkali-aggregate reactivity. Usually it is necessary to add the fly ash in addition to portland cement to accomplish the task, to maintain adequate strength development.
The use of finely ground water-granulated blast-furnace slag as a replacement for portland cement up to 65% can markedly reduce the alkali aggregate reaction and improve compressive strengths at the age of 28 days and beyond. To a significant degree, this procedure could help offset the quality problems often associated with cements of high-alkali content produced by energy efficient kiln systems. Finely ground water-granulated blast-furnace slag can be produced using only about one fifth the energy needed to produce an equal weight of portland cement.
Evaluation of Selected Procedures for the Rapid Analysis of Fresh Concrete
Authors: Head WJ , Phillippi HM , Howdyshell PA , Lawrence D 
Published: January 2010

Abstract
Presented in this paper are results of a program to evaluate procedures for the rapid determination of both cement and water contents of fresh concrete. Three generations of a general method were considered. The abilities of the current (Generation II-Construction Engineering Research Laboratory/Kelly Vail [CERL/KV]) and recently evolved (Generation III-Construction Engineering Research Laboratory/Concrete Quality Monitor [CERL/CQM]) procedures to aid in predicting cement and water contents of a variety of concrete mixtures were determined in an extensive series of side-by-side laboratory tests. Evaluated in the tests were effects of sampling techniques and aggregate type. Analysis of variance techniques were used as aids in establishing accuracy statements and comparing the two procedures. Results demonstrated that accuracies of the CERL/KV and CERL/CQM methods were equivalent for identical test conditions. Further, it was determined that aggregate characteristics affect results of both cement-content tests and both water-content tests.
Chemical Analysis of Portland Cement by Energy Dispersive X-Ray Fluorescence
Authors: Wheeler BD 
Published: January 2010

Abstract
X-ray fluorescence techniques have been applied for the analysis of portland cement for the past 20 or more years. During this time, applications have been developed primarily with wavelength spectrometers. In the past several years, development of solid state detectors has allowed energy dispersive X-ray fluorescence to detect and measure all the elements of interest in portland cement.
Determination by energy dispersive X-ray fluorescence displays excellent precision, but a linear calibration of intensity versus concentration for many elements exhibits significant deviation from a straight line. Particle size effects that could cause errors in the calibration were minimized through fine grinding. The remaining factors responsible for nonlinear calibrations relate to interelement effects, which are usually considered as absorption and enhancement.
The purpose of this investigation is to determine the interelement effects in portland cement and demonstrate the quantitative capabilities of energy dispersive X-ray fluorescence using certified National Bureau of Standards (NBS) portland cements as standard. An additional purpose is to demonstrate the application of empirical calculations for interelement effects in obtaining quantitative results utilizing Portland Cement Association check specimens as unknowns.
Interelement effects in X-ray fluorescence are well documented with various techniques utilized. Many of these programs are complex and correct all elements for the presence of all other elements and require a large number of standards. The approach used by the author is an exponential model based on intensities of the interferring elements.
Linear least squares fit of uncorrected intensities displayed absolute errors of 0.6% for alumina and silicon oxide to 1.0% for calcium oxide. Average deviations obtained following interelement corrections ranged from a low of 0.007% for potassium oxide to a high of 0.19% for calcium oxide. Analysis of each specimen consumed 200 s. The accuracy obtained by this method is well within the limits expected by the industry and the precision possible by alternate procedures.
Production Technology of Expanded Clay Aggregate Gravel with Bulk Density Below 300 kg/m3
Authors: Yaksharov OJ , Skiba BV 
Published: January 2010

Abstract
Some problems of production technology of expanded clay aggregate in a rotary kiln are considered with the use of the method of dusting the particles of burning material with refractory, or highmelting, powders. A list of the main units of modernization for the rotary kiln is given. Dependence upon the consumption of dusting materials is shown, and the conditions of its usage in rotary kilns are investigated. Comparative technical indexes of operation during the industrial tests in modernized rotary kilns with the use of devices under discussion are offered. Industrial tests are given for four kinds of argillaceous raw materials.
The use of the device to regulate the feeding of secondary air, which helps to reduce a fuel consumption at the expense of a decrease of heat loss by waste gases, is considered. The main technical and economic effects of using the devices under discussion in modernized rotary kilns are included.
Effects of Initial Field Curing on Standard 28-Day Cylinder Strengths
Authors: Meininger RC 
Published: January 2010

Abstract
Proposed changes to the initial curing of standard strength cylinders under ASTM Making and Curing Concrete Test Speciments in the Field (C 31) were studied. Cylinders were cured for periods of one or two days under four simulated field conditions: (1) 16°C (60°F) water, (2) 16°C (60°F) air, (3) 27°C (80°F) water, and (4) 27°C (80°F) air. After this initial curring period, all cylinders were given standard curing until 28-days age. Strength results were significantly affected by initial curing environment. Initial water curing at 16°C (60°F) resulted in 28-day strengths on the order of 5 to 7 MPa (700 to 1000 psi) more than concrete from the same batch cured initially in air at 27°C (80°F). It was also found that cement source has an influence on the strength difference because of initial curing environment and, also, on the temperature rise of the concrete cylinders during the first 6 h after molding. Increasing the initial curing period from one to two days only reduced compressive strength by about 1%.
High-Strength and Flowing Concrete with a Zeolitic Mineral Admixture
Authors: Feng N-Q , Li G-Z , Zang X-W 
Published: January 2010

Abstract
Zeolitic mineral admixture (ZMA) is made of the finely divided powder of natural zeolite with a bit of other agent such as triethanolamine. When ZMA is used to displace about 10% (by mass) of the ordinary portland cement (OPC) (strength grade No. 525) in concrete and mixed with a suitable amount of superplasticizer (W/C = 0.31 to 0.35), then a high-strength concrete with compressive strength of about 80 MPa and a slump of about 180 mm can be obtained. The strength of this concrete is about 10 to 15% higher than that of the corresponding concrete mixed with pure OPC, and its bleeding decreases greatly. It also results in no segregation or separation of the mix, and thus it satisfies the requirement of pumping concrete in construction.
The ZMA is suitable not only for the OPC but also for the slag portland cement. The strengthening effect of the ZMA is somewhat similar to that of silica fume. But the cost is only two thirds that of OPC. Thus, when ZMA is used to displace a certain amount of the cement in the concrete, the cost of the concrete thus made will be 3 to 5% cheaper than that of the corresponding concrete with pure cement.
The ZMA can increase the amount of micropores (d &lt; 625 Å) and decrease the amount of harmful large pores (d &gt; 938 Å) in the cement paste. Hence, the strength of concrete is increased and its other properties are also improved. Furthermore, ZMA can raise the SiO2/CaO weight ratio in the transition zone to increase its C-S-H phase and decrease its calcium hydroxide content. Thus, the structure of the transition zone is improved. Consequently, the strength and resistance to permeability of the concrete are increased.
Mechanical Properties, Abrasion Resistance, and Chloride Permeability of Concrete Incorporating Granulated Blast-Furnace Slag
Authors: Fernandez L , Malhotra VM 
Published: January 2010

Abstract
This paper reports the results of an investigation to determine the mechanical properties, abrasion resistance, and chloride-ion permeability of concrete incorporating ground-granulated blast-furnace slag from a source in northern Ontario. Nine 0.06-m3 air-entrained concrete mixtures involving 18 batches were made. The water-to-cementitious materials ratio of the mixtures ranged from 0.45 to 0.70, and the percentage of the slag used as a replacement by mass for the portland cement varied from 0 to 50%.
A number of test cylinders and prisms were cast for determining the mechanical properties of concrete, its chloride-ion permeability, and the effect of initial moist curing and subsequent air curing on its compressive strength. Test blocks were also cast for determining the abrasion resistance of concrete.
The strength development characteristics of the slag concrete indicate that granulated blast-furnace slag can be satisfactorily used as a partial replacement for portland cement in concrete. The abrasion resistance of the concrete containing slag is inferior to that of the control concrete without slag. The chloride-ion permeability of concrete decreases considerably when slag is used as a partial replacement for the portland cement, especially at the 50% replacement level.
Laboratory Evaluation of Wet and Dry Abrasion Resistance of Cement Mortar
Authors: Fwa TF , Low EW 
Published: January 2010

AbstractThis paper describes a laboratory test program conducted to evaluate the effect of wetting and drying on the abrasion resistance of portland cement mortar. A relatively simple and speedy abrasion test procedure was adopted. Test results indicated that repeated alternating of wetting and drying treatment did not have any adverse long-term effect on the abrasion resistance of specimens. Each wetting phase, however, reduced the abrasion resistance of specimens, although the reduction was only a short-term phenomenon. The abrasion resistance was restored to the original level gradually as the specimens were allowed to dry. The effect of wetting was found to be increasingly pronounced as the water/cement ratio of the test mix was raised.
Determination of Concrete Strength by Nondestructive Methods
Authors: Leshchinsky AM 
Published: January 2010

Abstract
This paper considers problems of improving the non-destructive control of concrete strength from the standpoint of: selecting the most economic methods; determining the required number of individual tests at a location to obtain an average in-place test result with the same degree of confidence by various methods; and modifying the acceptance criteria of ACI 318 to reduce the consumer's risk without changing the producer's risk. The ways of reducing labor consumption of nondestructive tests are recommended.
Calorimetric Study of Cement Blends Containing Fly Ash, Silica Fume, and Slag at Elevated Temperatures
Authors: Ma W , Sample D , Martin R , Brown PW 
Published: January 2010

Abstract
The hydration behavior of blended cements containing fly ash, silica fume, and granulated blast furnace slag over the temperature range of 10 to 55°C was studied by isothermal calorimetry. The rates of heat evolution during the first 24 h of hydration were examined. The results were analyzed to determine the kinetics of hydration of portland and blended cements. Relationships between the reactivities of these blended cements and the curing temperature were established. The results show that the rates of hydration reactions increased with an increase in temperature in all instances. Comparison among the blends containing fly ash, silica fume, and slag was made to establish activation energies for the hydration reactions. Arrhenius activation energy Ea values obtained were 39.0, 26.7, 30.4, and 49.3 KJ/mol for portland cement, fly ash, silica fume, and slag blended cements, respectively. The relatively constant Ea values for the blended cements may be related to diffusionally controlled hydration of the mineral admixtures.
Laboratory Measurements of Corrosion Activity of Steel Reinforcement in Concrete Using Simple Equipment
Authors: Wrobel P 
Published: January 2010

Abstract
This paper proposes the design and operation of a laboratory instrument for measuring the corrosion activity of steel reinforcement in concrete. An instrument was constructed and its reliability and research utility assessed against six steel-reinforced concrete prisms cured in duplicate under negligible, mild, and severe conditions of corrosivity. The steel reinforced concrete prisms were measured after curing and whilst dehydrating for corrosion potentials, polarization resistances, corrosion current densities, and corrosion rates. The instrument was simple to construct and operate. The instrument was reliable since it could apply Polarization Resistance to steel-reinforced concrete and thereby distinguish between steel reinforcements of different corrosion activity with precision. Furthermore, the instrument could be used to monitor changes in the corrosion activities of the steel reinforcements and was therefore useful for researching the passivating influence of Ca(OH)2. Erratum to this paper appears in 17(1).
Proportioning of Fly Ash Cement Concrete Mixes
Authors: Shashiprakash SG , Nagaraj TS , Raviraj S , Yenagi BV 
Published: January 2010

Abstract
The accumulation of fly ash throughout the world is several million tons per day. The main problem with the usage of fly ash is the slow rate of strength gain, primarily due to slow pozzolanic reactions. Existing methods of proportioning fly ash concrete are lacking. These methods are involved and do not directly take into account the properties of the constituent materials. The Generalized Approach for Mix Proportioning developed at the Indian Institute of Science, Bangalore, is the basis for the development of the proposed method, which takes into account the characteristics of cement, fly ash, and aggregates. Based on the basic trial mix data obtained by using the American Concrete Institute (ACI 211.1-81) method, the proportions of fly-ash concrete mixes were arrived at using the Generalized Approach for Mix Proportioning. The method proposed was applied to and found applicable for fly-ash concretes using fly ashes from two different sources.
Alkali Limits for Prevention of Alkali-Silica Reaction: A Brief Review of their Development
Authors: Hill ED 
Published: January 2010

AbstractThe optional limit on the Na2O equivalent of portland cement, 0.60% maximum, originated in the early 1940s following recognition of concrete distress caused by alkali-silica reaction by the California Division of Highways and the U.S. Bureau of Reclamation. Over the years, it has been effective in preventing distress from alkalisilica reaction in a great many, but not all cases. Aggregates have since been identified that require additional mitigating measures, such as inclusion of pozzolans. The need for different methods of aggregate evaluation has also been shown. Limits on the total alkali content of concrete have also been found useful. It is now apparent that a single alkali limit is impractical for all cases. The wide variety of natural aggregates requires that the cementitious materials be matched to the aggregates.The intent of this paper is to present some of the highlights in the development of methods to avoid deleterious alkali-silica reaction. No attempt has been made to present a complete review.
Selectivity of Alkaline Activators for the Activation of Slags
Authors: Shi C , Day RL 
Published: January 2010

Abstract
Ground-granulated blast-furnace slag is being used increasingly as a replacement of portland cement in concrete. A review of literature and results from experimentation show that alkaline activators have selectivity; that is, different activators have variable activation effects on slags from different origins. Analysis of hydration chemistry indicates that the selectivity results from the variation of hydration products and microstructure from different combinations of slag and activator. Selectivity of activators suggests that strength of a blast-furnace slag with NaOH solution (ASTM C 1073) is better used as an internal quality control index rather than a quality evaluation index. To improve the sensitivity of the quality control test, the alkali may be selected based on an activator-optimization testing rather than specifying an alkali.
The Use of the Flow Length Concept to Assess the Efficiency of Air Entrainment with Regards to Frost Durability: Part II—Experimental Results
Authors: Pleau R , Pigeon M , Laurencot JL , Gagné R 
Published: January 2010

Abstract
Samples from 20 concrete mixtures were submitted to microscopical examination in order to record the size-distribution of the circles intercepted by a plane and the chords intercepted by a line of traverse. These data were used to determine the flow length and other characteristics of the air-void system by using a numerical method developed earlier. The flow lengths were correlated to the results obtained from freezing and thawing tests previously carried out on the same concrete mixtures. They were also compared to spacing factors and Philleo factors obtained from the same experimental data. The results of these correlations confirm the validity of the flow length concept and the numerical method used to calculate it. They clearly suggest that the flow length is a better indicator of the frost durability of concrete than the commonly used Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete (ASTM C 457) spacing factor, and more realistic indication of the actual spatial distribution of air voids in concrete than the Philleo factor.
Monitoring the Influence of Water and Ionic Ingress on Cover-Zone Concrete Subjected to Repeated Absorption
Authors: McCarter WJ 
Published: January 2010

Abstract
This paper presents data from a test program investigating water and ionic movement in the cover region of reinforced concrete under a cyclic wetting and drying regime. Experiments were conducted over an eighteen month period on slabs containing OPC and OPC with partial replacement with PFA and GGBS, with samples being exposed to water and chloride solution. Water and ionic ingress through the cover zone was monitored by means of small conductivity probes embedded within the surface of 50-mm concrete specimens. The conductivity profiles obtained from the experimental program highlight the influence of repeated absorption on water and ionic ingress, hydration, pozzolanic activity and chloride binding. A simple electrical model was used to explain the influence of pore fluid and microstructure on conductivity. Traditional methods of examination were also employed to corroborate conductivity data and included cumulative volumetric gain, coring for carbonation and chloride ingress, and drillings for chloride concentration profiles.