Download or read book Hardened Concrete Properties and Durability Assessment of High Volume Fly Ash Concrete written by Kyle Marie Marlay and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Concrete is produced more than any other material in the world. Sustainable construction is extremely important in today's industry and fly ash is the leading material for sustainable concrete design. The addition of fly ash improves many fresh and hardened concrete properties. However, the slow hydration process associated with fly ash makes the use of the material in large amounts undesirable in conventional construction. This study evaluated the hardened concrete and durability performance of several high-volume fly ash (HVFA) concrete mixes. The various HVFA concrete mixes evaluated within this study consisted of 70 percent replacement of portland cement by weight of cementitious material and water-to-cementitious ratios (w/cm) ranging from 0.30 to 0.45. Studies were conducted on hardened properties including: compressive strength, flexural strength, splitting tensile strength, and modulus of rupture. A shrinkage analysis was also performed to evaluate drying and free shrinkage. The durability performance of the HVFA concrete was also evaluated. Results obtained from the tests revealed that compressive strengths of HVFA concrete are comparable to portland cement concrete with a reduced w/cm. Also, a reduction in concrete shrinkage was observed for HVFA concrete. The durability testing showed HVFA concrete increased the corrosion resistance and decreased the chloride penetration. Finally, existing relationships for hardened material properties and durability of conventional concretes are applicable to HVFA concretes"--Abstract, p. iii

Download or read book Fly Ash in Concrete written by K. Wesche and published by CRC Press. This book was released on 2004-03-01 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a state-of-the-art report which documents current knowledge on the properties of fly ash in concrete and the use of fly ash in construction. It includes RILEM Recommendations on fly ash in concrete and a comprehensive bibliography including over 800 references.

Download or read book Handbook on fly ash in concrete written by Dietmar Lutze and published by Verlag Bau+Technik. This book was released on 2013-03-20 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: When used as an addition and binder component, fly ash has become an indispensable construction material for many concrete applications. The conditions produced in power stations when firing fine pulverized coal result in the formation of a reactive, flour-fine, pozzolanic mineral material from the accompanying rock in the coal. Owing to its specific characteristics it has a positive impact on the properties of fresh and hardened concrete and facilitates cost-effective production of high-grade, durable concretes. The authors of this handbook have combined the latest discoveries from the field of research with practical experience of the use and effects of fly ash in concrete. This handbook provides the necessary information and makes interesting suggestions for selective use of fly ash in concrete.

Download or read book Hardened Mechanical Properties and Durability Performance of Specialized Concretes written by Kyle Richard Holman and published by . This book was released on 2012 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Concrete is one of the most produced and utilized materials in the world. Due to the labor intensive and time consuming nature of concrete construction, new and innovative concrete mixes are being explored. Self-consolidating concrete (SCC) is one such method of improving the overall cost and time efficiency of concrete production. SCC is a highly flowable form of concrete. This characteristic drastically reduces the amount of labor and time needed to place the concrete. The highly flowable nature also allows for much easier placement in applications of highly congested reinforcement. Another rising concern in today's construction industry is environmental responsibility. The addition of fly ash is a leading innovation in sustainable design of concrete. Fly ash, a waste by-product of coal burning power plants, can be used to replace a portion of the Portland cement in concrete. Investigators are pushing for higher and higher total replacement levels in what is known as high-volume fly ash (HVFA) concrete. However, minor issues observed with lower fly ash replacement levels may be exacerbated as the levels increase. In order to test both innovative concrete mixes, SCC and HVFA concrete was tested for both hardened material properties and durability in this investigation. The results indicated that SCC, with its time saving capabilities, was superior to conventional concrete, while HVFA concrete was comparable to conventional concrete in all areas except compressive strength"--Abstract, leaf iii.

Download or read book INCEPTION OF HIGH VOLUME FLY ASH WITH HYBRID FIBRE BASED CONCRETE A PERFORMER written by Dr. SS. Asadi & Dr. Vennam Swathi and published by Laxmi Book Publication. This book was released on 2024-01-20 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: When infrastructure is built quickly, development occurs. Concrete is the go-to material for construction projects. Manufacturing cement is a significant contributor to atmospheric carbon dioxide. Using carbon-neutral materials like crimson mud or powdered snail shells can reduce cement's carbon dioxide emissions by half. As an adaptable alternative to traditional concrete, HVFA concrete has many uses. Long-lasting and useful in Plain Cement Concrete (PCC) projects, fly ash also enhances concrete's workability. The positive effects of fly ash on the environment, such as lower carbon dioxide emissions, are not new. Adding fly ash to concrete increases its strength and segregation, which reduces its price and makes it simpler to pump.

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 High volume Fly Ash Concrete for Pavements Findings Volume 1 written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-volume fly ash concrete (HVFAC) has improved durability and sustainability properties at a lower cost than conventional concrete, but its early-age properties like strength gain, setting time, and air entrainment can present challenges for application to concrete pavements. This research report helps with the implementation of HVFAC for pavement applications by providing guidelines for HVFAC mix design, testing protocols, and new tools for better quality control of HVFAC properties. Calorimeter tests were performed to evaluate the effects of fly ash sources, cement-fly ash interactions, chemical admixtures, and limestone replacement on the setting times and hydration reaction of HVFAC. To better target the initial air-entraining agent dosage for HVFAC, a calibration curve between air-entraining dosage for achieving 6% air content and fly ash foam index test has been developed. Further, a digital foam index test was developed to make this test more consistent across different labs and operators. For a more rapid prediction of hardened HVFAC properties, such as compressive strength, resistivity, and diffusion coefficient, an oxide-based particle model was developed. An HVFAC field test section was also constructed to demonstrate the implementation of a noncontact ultrasonic device for determining the final set time and ideal time to initiate saw cutting. Additionally, a maturity method was successfully implemented that estimates the in-place compressive strength of HVFAC through wireless thermal sensors. An HVFAC mix design procedure using the tools developed in this project such as the calorimeter test, foam index test, and particle-based model was proposed to assist engineers in implementing HVFAC pavements.

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 Supplemental Proceedings Fourth International Conference on Fly Ash Silica Fume Slag and Natural Pozzolans in Concrete written by and published by . This book was released on 1992 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Evaluation of High volume Fly Ash HVFA Concrete Mixes written by Jeffery S. Voltz and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies, including those by the investigators, have shown that higher cement replacement percentages -- even up to 75 percent -- can result in excellent concrete in terms of both strength and durability. Referred to as high-volume fly ash (HVFA) concrete, this material offers a viable alternative to traditional portland cement concrete and is significantly more sustainable. However, HVFA concrete is not without its problems. At all replacement rates, fly ash generally slows down the setting time and hardening rates of concrete at early ages, especially under cold weather conditions, and when less reactive fly ashes are used. Furthermore, with industrial by-products, some variability in physical and chemical characteristics will normally occur, not only between power plants but also within the same plant. Consequently, to achieve the benefits of HVFA concrete, guidelines are needed for its proper application in bridges, roadways, culverts, retaining walls, and other transportation-related infrastructure components. The objective of this research was to design, test, and evaluate HVFA concrete mixtures. The study focused on the hardened properties of HVFA concrete containing aggregates and fly ash indigenous to the state of Missouri and developed guidelines on its use in infrastructure elements for MoDOT.

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 Volume Fly Ash Concrete Behavior in Structural Design written by Ahmad Fuzail Hashmi and published by . This book was released on 2023-03-13 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Volume Fly Ash Concrete (HVFA) is a type of concrete that incorporates a large volume of fly ash as a partial replacement for Portland cement. Fly ash is a by-product of coal combustion that is collected from power plants, and it has pozzolanic properties that can enhance the durability, workability, and strength of concrete. In HVFA, the replacement of Portland cement with fly ash typically ranges from 50% to 70% by mass, resulting in a reduction in the amount of cement required and a decrease in the carbon footprint of the concrete. However, this high volume of fly ash can also affect the behavior of the concrete in structural design. One of the main challenges in designing with HVFA concrete is the potential for delayed strength development. Fly ash reacts slowly with water, and this can result in a longer period for the concrete to reach its desired strength. This delayed strength development must be taken into account in the design process to ensure that the concrete can support the intended loads. Additionally, the use of HVFA can also affect the workability and setting time of the concrete. The high amount of fly ash can make the mixtures more viscous and harder to place, and it can also result in longer setting times. This can impact the construction schedule and require adjustments to be made in the mix design and placement procedures. On the other hand, HVFA can also provide benefits in structural design. The lower heat of hydration and reduced shrinkage characteristics of HVFA can minimize the potential for cracking and improve the long-term durability of the concrete. Furthermore, the use of fly ash can contribute to the overall sustainability of the project by reducing the carbon footprint and diverting waste from landfills. Overall, the behavior of HVFA concrete in structural design requires careful consideration of its unique properties and potential challenges. With proper mix design and construction practices, HVFA can provide a durable and sustainable option for concrete structures.

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 Self Compacting Concrete Materials Properties and Applications written by Rafat Siddique and published by Woodhead Publishing. This book was released on 2019-11-19 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-Compacting Concrete: Materials, Properties and Applications presents the latest research on various aspects of self-compacting concrete, including test methods, rheology, strength and durability properties, SCC properties at elevated temperature, SC manufacturing with the use of SCMs, recycled aggregates and industrial by-products. Written by an international group of contributors who are closely associated with the development of self-compacting concrete, the book explores the main differences between SCC and normal concrete in terms of raw materials, fresh properties and hardened properties. Other topics discussed include the structure and practical applications of fiber reinforced SCC. Researchers and experienced engineers will find this reference to be a systematic source to SCC with its accounting of the latest breakthroughs in the field and discussions of SCC constructability, structural integrity, improved flows into complex forms, and superior strength and durability. Offers a systematic and comprehensive source of information on the latest developments in SCC technology Includes mix design procedures, tests standards, rheology, strength and durability properties Explores the properties and practical applications of SCC

Download or read book Fly Ash in Concrete written by R C Joshi and published by CRC Press. This book was released on 1997-11-13 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since it was first recognized as a mineral admixture for concrete in the 1930's, fly ash has been the subject of worldwide study as researchers work to maximize its economical and environmental benefits. In recent years, investigations have focused on the physical, chemical and mineralogical characteristics of fly ash and their specific correlation to the performance of concrete. This book collects the latest results from these various studies and offers a complete review of the advantages of fly ash as an admixture in concrete, including strength development and improved chemical resistance and durability. A review of the current international standards on fly ash usage is provided, in addition to an extensive reference list and a complete survey of various other fly ash products, such as bricks, mineral wool and gypsum wall boards, as well as the use of fly ash in waste management.

Download or read book Concrete Durability and Service Life Planning written by Konstantin Kovler and published by Springer Nature. This book was released on 2020-04-28 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gathers the proceedings of the 3rd International RILEM Workshop on Concrete Durability and Service Life Planning (ConcreteLife’20), held in Haifa, Israel in January 2020. The papers cover a range of topics in concrete curing, cracking in concrete structures, corrosion of steel in concrete, thermal and hygral effects, concrete in cold climates and under high temperatures, recycling, alkali-silica reactions, chloride and sulfate attacks, marine structures, transport phenomena, durability design, microstructure of concrete and volume changes, and life cycle assessment. The book also explores future trends in research, development, and practical engineering applications related to durable concrete construction, and focuses on the design and construction of concrete structures exposed to various environmental conditions and mechanical loading. Given its scope, it offers a valuable asset for all researchers and graduate students in the areas of cement chemistry, cement production, and concrete design.

Download or read book Effects of High Volume Fly Ash and Powder Activators on Plastic and Hardened Concrete Properties written by Drew Alexander Davis and published by . This book was released on 2012 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was performed to examine the effects of high volumes of Class C fly ash modified by powder activators upon the plastic and hardened properties of concrete. In a companion study, five Missouri area cements and five Class C fly ashes were examined for incompatibilities, with the most and least reactive combinations being scaled up to full scale concrete testing. Two baseline concrete mixtures were examined, the only difference in mixtures being the sources of portland cement and fly ash. Fly ash replacement was examined at 50% and 70% replacement (by total cementitious mass). Three powder activators were used in combination with the cement and fly ash mixtures: 4% gypsum, 10% hydrated lime, and 20% rapid set cement (by mass of fly ash). Gypsum was present in all concrete mixes, with either hydrated lime or rapid set cement acting as an activator in combination with it. Both plastic concrete and hardened concrete properties were examined. The use of powdered activators in combination with fly ash resulted in the concrete exhibiting adequate 28 day strength, stiffer moduli, less drying shrinkage, lower chloride permeability, and improved resistance to freezing and thawing at 50% fly ash replacement when compared to a baseline mix, although the mixture suffered in abrasion resistance and salt scaling resistance. At 70% fly ash replacement, the mixtures performed poorly compared to their baseline counterparts, even with the addition of rapid set cement. The choice of activator primarily affected the early age strength and setting time, with rapid set cement mixtures exhibiting a quicker set and a higher earlier strength than the hydrated lime mixtures, though this did not correspond to improved characteristics in the long term. In applications where early properties are not important, the use of less expensive calcium hydroxide is recommended. In any applications, however, the specific cement and fly ash sources should be examined for possible incompatibilities.