bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical and Petrographic Analyses and ASTM Test Procedures for the Study of Delayed Ettringite Formation
Authors: Hime WG , Marusin SL , Jugovic ZT , Martinek RA , Cechner RA , Backus LA 
Published: January 2010

Abstract
Although many papers have been written on case studies of incidences of delayed ettringite formation (DEF), few demonstrate a careful study of the methods of analyses for the presence and concentration of the ettringite that has formed. In addition, possibly only one suggests a method to determine potential future development of destructive ettringite.
Furthermore, there have been few papers that relate to methods of test for the potential that portland cements have in causing DEF, especially under conditions where curing temperatures are low.
Our studies involving DEF have not only led us to develop improved analytical methods and tests, but have also demonstrated deficiencies in several techniques employed by other investigators, and formerly even by us. We have also studied the methods for their application as ASTM standards and procedures.
This paper presents our analysis methods and test procedures. The following are discussed: 1. Petrographic procedures for DEF study, including discussions of their application, advantages, and deficiencies. 2. Scanning electron microscopy procedures for DEF identification and development, including sample preparation, backscatter and secondary electron procedures, elemental dot-mapping, and flashing materials (conductive coatings) for the sample surface. 3. Qualitative and quantitative analyses for ettringite, including X-ray diffraction (XRD) and differential thermal analysis (DTA). 4. Procedures for quantifying the potential degree of future DEF development in concrete, using accelerated hydration and DTA determination of any additional ettringite developed. 5. Quantitative procedures for determining the amount of ettringite formed, for example at 24 h, as influenced by component concentration changes (e.g., potassium sulfate versus gypsum).
6. Use of ASTM methods for the evaluation of a cement for DEF potential.
Development of Performance Tests for Sulfate Attack on Cementitious Systems
Authors: Day RL 
Published: January 2010

Abstract
Delayed ettringite formation (DEF) is only one of a number of chemical and physical attack mechanisms related to the presence of sulfur-based compounds existing within the microstructure of concrete. Identification of the various “sulfate” attack mechanisms, both internal and external, is important to guide the development of appropriate performance-based test methods. Such test methods must also recognize and account for the fact that real deterioration processes in concrete often involve a combination of mechanisms; sulfate attack, for example, is often found in combination with other attack mechanisms, such as alkali-aggregate reaction or freezing and thawing. Thus, future tests or suites of tests should be designed to account for acceleration of deterioration that results from the synergy between attack mechanisms. It is suggested that a holistic approach—similar to that proposed by Mehta—whereby the effect of (a) combinations of raw materials and (b) combinations of environmental influences should play a central role in the development of new standards.
In this paper, an engineering view of the various mechanisms of sulfate attack is provided. Sulfate-attack mechanisms are categorized and major influences upon these mechanisms are briefly reviewed. The suitability of two key tests related to sulfate attack is examined—ASTM methods C 1012 and C 1038. Available data concerning test method C 1038 are analyzed. Because of the lack of confidence that C 1038 is an adequate performance test, reliance upon prescriptive limits for sulfate and aluminate contents and their relative proportions is currently a better approach to ensure adequate performance of cementitious systems in practice.
Setting of Cement and Concrete
Authors: Struble L , Kim TY , Zhang H 
Published: January 2010

Abstract
The standard test for setting of cement provides little understanding of how the cement behaves in concrete. Setting is measured for both cement and concrete using penetration resistance, but the standard tests for these two materials are quite different. With cement, the penetration is usually measured using the Vicat needle; with concrete, the penetration is measured using a series of Proctor needles, which vary in diameter. There is no theory to relate the tests to one another, although data are presented showing empirical relationships between the Vicat and the Proctor measurements. These tests utilize quite different samples: the Vicat test utilizes cement paste, and the Proctor test utilizes mortar extracted from concrete. The Vicat test utilizes a very stiff paste with a very low water-to-cement ratio, and the water-to-cement ratio is seen to have a substantial effect on the way cement paste stiffens. However, it is shown here that fluid pastes, more representative of paste in ordinary concrete, can be tested using either the Vicat or the Proctor. Setting may be studied using rheology, and a dynamic rheology test has been developed in our laboratory. This test provides similar results as the standard setting tests, but does not allow measurement of initial or final set. Based on these results, modifications in the cement test are proposed to improve the correlation with concrete setting, and advantages of a rheology-based definition of set are discussed.
On the Effect of Coarse Aggregate Fraction and Shape on the Rheological Properties of Self-Compacting Concrete
Authors: Geiker MR , Brandl M , Thrane LN , Nielsen LF 
Published: January 2010

Abstract
Rheological measurements have been undertaken to illustrate the applicability on fresh self-compacting concrete of a model for the relative viscosity and yield stress of suspensions. The model is based on linear viscoelasticity and classical theory for composite materials and it takes into account the amount, shape (aspect ratio of ellipsoids), and maximum packing density of the particles (here aggregates), as well as the rheological properties of the matrix (here mortar). Self-compacting concretes made from different types of coarse aggregates: spheres (glass beads), sea dredged, crushed, and a mix of sea dredged and crushed aggregates, have been tested in a coaxial cylinder concrete rheometer (BML). The investigations indicate that the aspect ratio, angularity, and surface texture of aggregates affect the viscosity and yield stress. The magnitude of these effects depends on the property in question, viscosity and yield stress.
Dependence of Rate of Absorption on Degree of Saturation of Concrete
Authors: Nokken MR , Hooton RD 
Published: January 2010

Abstract
Sorption is a term used for water ingress into pores under unsaturated conditions due to capillary suction. Sorptivity testing has been used as a measure of the ability of concrete to absorb water. Sorptivity tests were conducted on three concrete mixtures, which had been preconditioned to various initial moisture contents. Results show that the sorptivity is dependent on initial water content as well as the water to cement ratio of concrete. A linear trend was found relating normalized sorptivity values to degree of saturation.
An Experimental Study on Potential of Cement Kiln Dust in Stabilization of Fly Ash
Authors: Kumar R , Kanaujia VK , Ranjan A 
Published: January 2010

Abstract
This study investigates the feasibility of using two waste materials i.e., Cement kiln dust (CKD) and Fly Ash (FA) together in the construction of highway embankment/road works. In this work, fly ash was stabilized with different proportions of CKD and the potential of CKD in stabilizing fly ash was investigated. The experimental results conclude that CKD can be successfully used for stabilization of fly ash and hence the stabilized fly ash can be used in bulk in the construction of highways embankments/road works.
Towards Standardization of a Rapid Chloride Conduction Test for Concrete
Authors: Streicher PE , Alexander MG 
Published: January 2010

Abstract
The paper describes the development and standardization of a rapid chloride conduction test for concrete. The test has a sound theoretical basis, is rapid, efficient and simple to perform, and is of low cost. Results are given which show that vacuum saturation is a suitable procedure to pre-saturate samples with a 5 M sodium chloride solution, for standard sample sizes and “normal” concretes. A ruggedness test was conducted to determine the degree to which the conditions specified in the test method must be controlled. Results show that the test is sufficiently rugged to accommodate small changes in the operating conditions, and that it is possible to achieve consistent results. The paper also reviews the standard test method. Precision for the test is best characterized by the coefficient of variation, which typically is less than 7% for a set of results from properly conducted tests.
Treatment of Medium- to Coarse-Grained Sands by Fine-Grained Portland Cement (FGPC) as an Alternative Grouting Material to Silicate-Ester Grouts
Authors: Mollamahmutoğlu M 
Published: January 2010

Abstract
Due to the inability of Ordinary Portland Cement (OPC) grouts to permeate such soil formations as fine- to medium-grained and/or medium- to coarse-grained sands and the problems associated with permanence and toxicity of chemical grouts, advanced studies have shown that fine grained portland cement (FGPC) based grouts may be used to overcome the difficulties mentioned above and hence, an opening in the market has appeared for the manufacture of very fine-grained cements. In this context, comparative laboratory studies were conducted on commercially available OPC, FGPC, and silicate-ester grouts, and it has been found that FGPC has better flow properties and bleed characteristics than OPC. Furthermore, its permeation into medium- to coarse-grained sand is as effective as silicate-ester grout and the strength of the sand gained by the injection of FGPC is higher than that of silicate-ester grouted sand.
Strength and Sulfate Resistance of Concrete Made With High Alumina Cement, Type 10 Portland Cement, Type 10 Portland Cement Plus Fly Ash and Type 50 Portland Cement
Authors: Gillott JE , Quinn T 
Published: January 2010

Abstract
Concrete prisms and cylinders were made using four different cementitious materials. These were high alumina cement (HAC), Type 10 Portland, Type 10 with 20% replaced with fly ash and Type 50 Portland Cement. Specimens were used for measurement of length change and estimation of compressive strength over a period of about 18 months exposure to fog-room conditions, room temperature Na2SO4 solution or 40°C water bath. None of the concrete samples made with the 3-types of Portland-based cementitious material showed distress due to sulfate attack. The concrete made with HAC and which had probably not undergone the conversion reaction also showed good resistance to sulfate attack but samples in which conversion had probably occurred cracked and disintegrated in the Na2SO4 solution.
The Omani Artificial Pozzolans (Sarooj)
Authors: Al-Rawas AA , Hago AW , Al-Lawati D , Al-Battashi A 
Published: January 2010

Abstract
Sarooj is a local Omani term for artificial pozzolana produced by calcining clays. Calcined clay mixed with lime and water has been used as a cementing material for a long time. It has been used widely in hydraulic structures due to its good hydraulic properties and in military defensive installations due to its durability. This project focuses on the exploration of potential clay areas in Oman for the production of sarooj. A large number of samples have been collected from different sites in the country and were subjected to an extensive program of testing involving chemical, mineralogical, thermal, and physical analyses. This paper presents some of the results obtained for samples tested from five locations in Northern Oman (Al-Khod, Soor Al-Haboos, Al-Fulaij, Al-Hamra, and Al-Awabi). It was found that the sarooj produced by Al-Fulaij clays has higher strength than those of other sites. It was also found that the total content of silica, alumina, and iron oxide together with the burning temperature and the duration of burning have significant effect on the physical properties of the sarooj produced.
Testing Abrasion Resistance of High-Strength Concrete
Authors: Sonebi M , Khayat KH 
Published: January 2010

Abstract
Several high-strength concrete types with compressive strength up to 120 MPa were tested to evaluate the suitabilities of two test standards to evaluate abrasion resistance of concrete subjected to wearing caused by heavy tire and steel wheel traffic and heavy trucking and water-borne debris. The selected tests were ASTM C 779, Procedure C, Test Method for Abrasion Resistance of Horizontal Concrete Surfaces, and ASTM C 1138, Test Method for Abrasion Resistance of Concrete (Underwater Method). Because of the low rate of abrasion damage of high-strength concrete, the need to prolong the test duration of the mechanical abrasion test from 20 to 40 min and that of the underwater test from 72 to 96 and 120 h to better differentiate between various levels of abrasion was evaluated. The study also evaluated the differences in wear damage resulting from testing the finished, molded, or saw-cut surfaces of high-strength concrete.
Both ASTM procedures are found to be suitable for testing the abrasion resistance of high-strength concrete. The recommended test duration of 20 min and 72 h for the ASTM C 779 and C 1138 tests, respectively, are sufficient to differentiate between the levels of wear damage of high-strength concrete. Good correlations exist between the wear damage measured at 72 h and those determined at 48, 96, and 120 h for the underwater test and 10 and 20 min results for the mechanical abrasion test.
The evaluation of the abrasion resistance of saw-cut surfaces can yield considerably lower abrasion damage and smaller variations in within-test results than testing finished or molded surfaces.
User and Producer Perspectives on ASTM C 1157
Authors: Tennis PD , Melander JM 
Published: January 2010

Abstract
ASTM C 1157 has undergone several changes since it was first adopted in 1992 as a performance specification for blended cement. Those changes have increased the number of available options and broadened the scope of the standard to include portland cement. However, the level of acceptance and use of ASTM C 1157 by specifiers and manufacturers remains limited. Barriers to acceptance include a disinterest or lack of familiarity with the specification, the slow process for adopting the specification in referencing standards and building codes, concerns with respect to test methods, and difficulties in interpreting the standard. For example, it has been noted that the strength requirements are unusually complex due to the wide range of options available.
A Task Group of National Ready Mixed Concrete Association (NRMCA) and Portland Cement Association (PCA) members has been reviewing C 1157 and has suggestions for revisions to address concerns raised. These potential changes and their rationales are discussed. Included are: reexamination of strength requirements, evaluation of test methods, modification of some provisions, and suggestions for additions to the standard.
The Damage Rating Index Method for ASR Affected Concrete—A Critical Review of Petrographic Features of Deterioration and Evaluation Criteria
Authors: Rivard P , Fournier B , Ballivy G 
Published: January 2010

Abstract
The Damage Rating Index method has recently been used with success in several cases of damage evaluation in structures affected by alkali-silica reaction in Canada and in Brazil. Although this petrographic method is starting to be widely used and is in the process of becoming integrated as a Canadian standard, it has not been modified yet from the original design. An evaluation of the method is presented in this paper. According to data obtained from many petrographic examinations, the number of cracks in coarse aggregates (filled or not with silica gel) seemed to show to best correlation with the expansion measured on laboratory concrete specimens made with Spratt limestone. The reaction rim is not a real “damage” feature and should not be considered as one but as a “degree of reaction” feature. In an attempt to improve the DRI method for assessing damage related to ASR, a new parameter should be introduced, which takes into account cracks running from aggregate particles to cement paste. The geological nature of the rock used as concrete aggregate may influence the reaction mechanism as well as the petrographic features related to ASR. Comparing concrete specimens subjected to ASR, which incorporate different aggregate types may, in some instances, be influenced by the type of reaction produced by the various reactive rocks and minerals in each aggregate.
Use of Cement By-pass Dust in Flowable Fill Mixtures
Authors: Al-Jabri K , Taha R , Al-Harthy A , Al-Oraimi S , Al-Nuaimi A 
Published: January 2010

Abstract
Flowable fill is a self-compacted, cementitious material used primarily as a backfill in lieu of compacted fill. It is generally a mixture of sand, small amount of cement, fly ash, and water. Sand is the major component of most flowable fill mixes. Waste materials such as fly ash, ground granulated blast furnace slag, and foundry sand are commonly used to ensure low maximum compressive strength. Cement by-pass dust (CBPD) is considered a waste material of the production of cement. An estimated 25,000 tons of CBPD are produced annually in the Sultanate of Oman by Oman Cement Company alone. Most of this material is not effectively used and is disposed of on-site without any reuse causing environmental concerns. The main objective of this research is to investigate the potential use of CBPD in flowable fill mixtures as an alternative to fly ash and as a partial substitute for cement. The physical and chemical properties of both CBPD and cement were determined. Cube and cylindrical samples were prepared using different proportions of CBPD and water-to-cement ratios in order to select the optimum mixes that can be used in flowable fill applications. The optimum mixtures were cured in air and covered in plastic bags in order to study the effect of curing method on the compressive strength of flowable fill mixtures. Promising results were obtained with respect to the use of CBPD as a partial or full substitute for cement in flowable fill mixtures. Results also demonstrated that air cured samples gave a higher compressive strength than samples cured in the plastic bags for the mixes where CBPD was used as a partial substitute for cement. However, in mixes where CBPD was used to fully replace cement, samples that were cured in plastic bags produced higher strength than air cured samples at longer curing periods.
Reappraisal of the Autoclave Expansion Test
Authors: Helmuth R , West PB 
Published: January 2010

Abstract
This report re-examines the technical basis for the AET as presented inPCA Research Department Bulletin RX45 as well as more recent research. Thefocus is on the potential for disruptive expansions caused by crystallineMgO in portland cements hydrated under various conditions, including the AET.Much of the data indicates that the AET would be a good test for unsoundnesscaused by free CaO alone, but that expansions in the AET caused by MgO andC3A do not correlate well with disruptive expansionsunder ordinary conditions. Consideration of expansive reaction mechanismsand the published data indicate that MgO continues to hydrate slowly undera wide range of conditions and that stress-relief mechanisms and stabilizationprocesses apparently operate to prevent disruptive expansions in moist environments.Since these mechanisms may not operate as well in dry environments, thereare undetermined risks with respect to reliance on performance tests thatdo not cause hydration of MgO. Investigation of these mechanisms is recommendedso that portland cement soundness and performance can be assured, perhapswithout reliance on the AET.
Comparison of Air Contents in Fresh and Hardened Concretes Using Different Airmeters
Authors: Khayat KH , Nasser KW 
Published: January 2010

Abstract
The air contents of several concrete mixtures were measured while the material was in a plastic state, and the results were compared to corresponding values determined microscopically on the same hardened concretes. Two volumetric airmeters, a roller and a mini airmeter, as well as a pressure airmeter were employed for monitoring the air content in fresh concrete. The linear traverse method was used to determine the air content of hardened concrete. A total of 21 laboratory-prepared concrete mixtures were examined. Both 10 and 25-mm (3/8 and 1-in.) nominal size aggregates of different densities were used to produce normal-weight and lightweight concretes. The water-cementitious materials ratios for the concretes ranged between 0.23 and 0.53, and the cement content varied from 267 to 540 kg/m3 (450 to 910 lb/yd3), with silica fume incorporated in some concretes. An air-entraining agent was used to yield air contents between 0.5 and 12.5%.
For the materials used in this investigation, the test results indicate that the air content in the fresh concrete can be 0.5 to 1.5% greater than that actually present in the hardened concrete. The mean discrepancy between the air contents of fresh and hardened concretes is 22, 13, and 19%, respectively, when the pressure, roller, and mini airmeters are used. For any single airmeter, the spread between air contents of fresh and hardened concretes increases with the reduction in compressive strength. Similar decrease is observed when the nominal size of aggregate increases.
Evaluation of Concrete Mixtures for Underwater Pile Repairs
Authors: Khayat KH , Hester WT 
Published: January 2010

Abstract
Repair of submerged concrete piles that have undergone considerable loss in cross section and strengthening of existing marine piles often involves jacketing the piles and filling the annular spacings between the jackets and the piles with concrete. In this paper, physical and mechanical properties that are deemed necessary to secure high-quality concrete under water were evaluated for numerous mixtures. Four concrete mixtures were selected to repair 2.4-m (8-ft)-high mock-up piles located above water. Rigid rectangular forms were erected around the 203-mm (8-in.)-square mock-up piles. The resulting annular spacings between these forms and the mock-up piles were first filled with water and then with concrete. The concrete was discharged within previously placed unhardened concrete to minimize segregation and water dilution rather than allowed to fall through water. Once the repair had set, the exposed surface of each underwater-cast pile was examined for any signs of segregation. Cores were obtained to evaluate the in-situ density and compressive strength of the concrete, as well as the bond strength between the underwater-cast concrete and the central mock-up pile. The testing program indicates that concrete mixtures containing antiwashout admixtures and either silica fume or fly ash can secure higher quality repairs, at equal or lower costs, than similar concretes made with high silica fume or high cement contents and no antiwashout admixtures. Properly proportioned concrete mixtures resulted in exposed repair surfaces free of segregation, with mean in-place compressive strength in excess of 58.6 MPa (8500 psi). The in-situ density of such concrete was identical to that cast and consolidated above water, and the bond strength to existing mock-up piles was in excess of 2.1 MPa (300 psi).