Download or read book Discussion of Optimizing the Amount of Class C Fly Ash in Concrete Mixtures by R M Majko and M F Pistilli written by W. Barry Butler and published by . This book was released on 1985 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimizing the Amount of Class C Fly Ash in Concrete Mixtures written by RM. Majko and published by . This book was released on 1984 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of a two part research program on several laboratory air-entrained concrete mixtures designed to contain increasing amounts of moderately cementitious Class C fly ash. In the first part of the paper, a Type A admixture was used in half of the mixtures, treating both the portland cement Type I and fly ash (15% calcium oxide). In the second part of the paper, three other Class C fly ashes (9 to 12% calcium oxide) were extensively tested in concrete that contained a Type A admixture (but this time treating only the cement). Two very high lime fly ashes (25 to 30% calcium oxide) were also tested in concrete mixtures.
Download or read book Cement Concrete and Aggregates written by American Society for Testing and Materials and published by . This book was released on 1984 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High volume Fly Ash Concrete Technology written by and published by . This book was released on 1992 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods for Evaluating Fly Ash for Use in Highway Concrete written by Lawrence L. Sutter and published by Transportation Research Board. This book was released on 2013 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) 749: Methods for Evaluating Fly Ash for Use in Highway Concrete presents suggested changes to coal fly ash specifications and test protocols contained in American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Transportation Materials and Methods of Sampling and Testing (AASHTO M 295). The changes suggested include modifications to the test methods currently specified for evaluating acceptability of fly ash for use in highway concrete as well as the introduction of new test methods for enhancing such evaluations. Attachment C: Details of the Research into Methods for Evaluating Fly Ash Use in Highway Concrete is only available online."--Publisher description.
Download or read book Optimizing the Use of Fly Ash in Concrete written by M. D. A. Thomas and published by . This book was released on 2007 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The optimum amount of fly ash varies not only with the application, but also with composition and proportions of all the materials in the concrete mixture (especially the fly ash), the conditions during placing (especially temperature), construction practices (for example, finishing and curing) and the exposure conditions. This document discusses issues related to using low to very high levels of fly ash in concrete and provides guidance for the use of fly ash without compromising the construction process or the quality of the finished product. The nature of fly ashes including their physical, mineralogical and chemical properties is covered in detail, as well as fly ash variability due to coal composition and plant operating conditions. A discussion on the effects of fly ash characteristics on fresh and hardened concrete properties includes; workability, bleeding, air entrainment, setting time, heat of hydration, compressive strength development, creep, drying shrinkage, abrasion resistance, permeability, resistance to chlorides, alkali-silica reaction (ASR), sulfate resistance, carbonation, and resistance to freezing and thawing and deicer salt scaling. Case studies were selected as examples of some of the more demanding applications of fly ash concrete for ASR mitigation, chloride resistance, and green building.
Download or read book Optimization of Soil Stabilization with Class C Fly Ash written by John Michael Pitt and published by . This book was released on 1987 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous Iowa DOT sponsored research has shown that some Class C fly ashes are ementitious (because calcium is combined as calcium aluminates) while other Class C ashes containing similar amounts of elemental calcium are not (1). Fly ashes from modern power plants in Iowa contain significant amounts of calcium in their glassy phases, regardless of their cementitious properties. The present research was based on these findings and on the hyphothesis that: attack of the amorphous phase of high calcium fly ash could be initiated with trace additives, thus making calcium available for formation of useful calcium-silicate cements. Phase I research was devoted to finding potential additives through a screening process; the likely chemicals were tested with fly ashes representative of the cementitious and non-cementitious ashes available in the state. Ammonium phosphate, a fertilizer, was found to produce 3,600 psi cement with cementitious Neal #4 fly ash; this strength is roughly equivalent to that of portland cement, but at about one-third the cost. Neal #2 fly ash, a slightly cementitious Class C, was found to respond best with ammonium nitrate; through the additive, a near-zero strength material was transformed into a 1,200 psi cement. The second research phase was directed to optimimizing trace additive concentrations, defining the behavior of the resulting cements, evaluating more comprehensively the fly ashes available in Iowa, and explaining the cement formation mechanisms of the most promising trace additives. X-ray diffraction data demonstrate that both amorphous and crystalline hydrates of chemically enhanced fly ash differ from those of unaltered fly ash hydrates. Calciumaluminum- silicate hydrates were formed, rather than the expected (and hypothesized) calcium-silicate hydrates. These new reaction products explain the observed strength enhancement. The final phase concentrated on laboratory application of the chemically-enhanced fly ash cements to road base stabilization. Emphasis was placed on use of marginal aggregates, such as limestone crusher fines and unprocessed blow sand. The nature of the chemically modified fly ash cements led to an evaluation of fine grained soil stabilization where a wide range of materials, defined by plasticity index, could be stabilized. Parameters used for evaluation included strength, compaction requirements, set time, and frost resistance.
Download or read book Making Better Concrete written by Bruce King and published by Green Books. This book was released on 2005 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why a book about concrete? Because we use so much of it -- far more than any other building material. It seems only sensible to inquire as to how we can use this ubiquitous building material without undue damage to the life and landscapes that surround us. You may have heard of fly ash as an eco-friendly alternative to using portland cement in concrete, but until now there has been no easy guide to how it makes superior concrete, or to how to use it. This book isn't just for people who want to "build green" -- it's for people who want to build better concrete.
Download or read book Updating Physical and Chemical Characteristics of Fly Ash for Use in Concrete written by Prasanth Tanikella and published by . This book was released on 2018-02-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: When incorporated in concrete mixtures, fly ashes are known to influence both its fresh and hardened properties. An accurate and quick technique to predict the extent of this influence based on the characteristics of fly ash would be highly beneficial in terms of field applications. The current study was an attempt to quantify the effects of fly ashes on the properties of pastes as a function of: (a) the mean particle size of the fly ash particles, (b) their fineness and (c) their chemical composition. In addition, since the type and the amount of glass present in the fly ash significantly affect its reactivity, this property was also included in the investigation.Twenty different fly ashes (both, ASTM Class C and Class F), obtained from power plants in and around Indiana, were characterized during the Phase 1 of the study. The information collected included: physical characteristics, chemical composition and the amount and type of glass present. Phase 2 of the study consisted of evaluation of various properties of binary paste systems (portland cement with 20% of cement of fly replacement). The evaluated properties included: the set time, the heat of hydration, the strength activity index, the non-evaporable water content and the amount of calcium hydroxide formed at different ages.These results obtained from both phases of the study were used to build statistical models for prediction of previously evaluated properties for any hypothetical fly ash with similar characteristics. The models included only the most significant variables, i.e., those which were found to most strongly affect any specific property. The variables to be included in the model were selected based on the adjusted R2 values.As a result of the modeling process, it was found that the sets of statistically significant variables affecting the properties consisted of both physical and chemical characteristics of the fly ash and that the combination of these variables was unique for each property evaluated.
Download or read book Engineering Properties of High Performance Concrete Containing Large Volume of Class C Fly Ash written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation for the use of large volume of fly ash in concrete in combination with superplasticizer, was for the purpose of optimizing its mechanical properties while reducing its cost. Several concrete mixtures using coarse/fine aggregate ratio of 1.22 and aggregate/binder ratio of 5.1 were investigated. Fly ash was used as a partial replacement of type 10 Portland cement at levels ranging between 20-60% by weight of the total cementitious materials in the mixture. Use of superplasticizer allowed a reduction of the water/binder ratio to 0.28-0.33, while the K-slump of fresh concrete was kept at a practical level of 25%. The effect of fly ash on the development of the compressive strength of the hardened concrete was determined. The selection of a concrete mixture with an optimum fly-ash/cement ratio was based on compressive strength results and cost. Concrete with compressive strength levels of 50 MPa, applicable to mid-rise buildings, mine structural components and bridge construction, was obtainedby taking advantage of the water reducing properties of superplasticizers, and by replacing 50% of the cement with Class C fly ash. The 28-day compressive strength of the resultant concrete was approximately 80% of the strength of the identical control mixture containing no fly ash replacement of the cement; at 56 and 91 days, the strength of the resultant mixture improved and eventually became identical to that of the control mixture. The above results were achieved with a 10% reduction in cost, which is a significant savings for the construction industry. The selected mixture was tested for its engineering properties of strength, elasticity, shrinkage and creep, and the results were compared to the same properties of a control mixture. Creep and shrinkage are important concrete properties in prestressed and reinforced concrete structures. Time-dependent deformation of concrete due to creep and shrinkage, results in partial loss of the prestress force and produce.
Download or read book Evaluation of Class C Fly Ash in Sulfate Environments written by Kevin J. Folliard and published by . This book was released on 2008 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Best Practices Guide for High volume Fly Ash Concretes written by Dale P. Bentz and published by CreateSpace. This book was released on 2014-06-24 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: A best practices guide is developed from a synthesis of recent research on high-volume fly ash (HVFA) concrete mixtures. These best practices can be applied by the concrete construction industry to achieve desired properties and to ensure the (high) performance of HVFA concrete mixtures in practice. As such, the report considers all aspects of HVFA concrete production, from the characterization of the starting materials, through mixture proportioning and curing options to achieve desired properties, to the in-place early-age and long-term performance of the concrete in its fresh and hardened states. Both mechanical and transport properties are considered in detail. Perspective is established based on a brief review of current practices being employed nationally. Each topical section is concluded with a practice-based set of recommendations for the design and construction community. The report is intended to serve as a valuable resource to these communities, providing both a research summary and a guide to practical steps that can be taken to achieve the optimum performance of these sustainable concrete mixtures.
Download or read book High performance High volume Fly Ash Concrete written by V. Mohan Malhotra and published by . This book was released on 2005 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supplementary Cementing Materials written by Rafat Siddique and published by Springer Science & Business Media. This book was released on 2011-03-28 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an attempt to consolidate the published research related to the use of Supplementary Cementing Materials in cement and concrete. It comprises of five chapters. Each chapter is devoted to a particular supplementing cementing material. It is based on the literature/research findings published in journals/conference proceeding, etc. Topics covered in the book are; coal fly ash, silica fume (SF), granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Each chapter contains introduction, properties of the waste material/by-product, its potential usage, and its effect on the properties of fresh and hardened concrete and other cement based materials.
Download or read book Use of Fly Ash in Concrete written by and published by . This book was released on 1989 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cement Chemistry written by H F W Taylor and published by Thomas Telford. This book was released on 1997-04 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: A revised and updated text on cement chemistry. This edition forms a comprehensive and in-depth reference work that explains in detail all aspects of cement chemistry.
Download or read book Prevention of Thermal Cracking in Concrete at Early Ages written by R. Springenschmid and published by CRC Press. This book was released on 1998-10-01 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important new report from the RILEM Technical Committee 119. This book presents models and methods to determine thermal stresses and cracking risks in concrete. The possible influences on and causes of thermal cracking of concrete are discussed and cases of practical measures for avoiding cracking are detailed.
