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 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 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 An Experimental Evaluation of High Volume Fly Ash HVFA Structural Concrete Made from Recycled Aggregate written by Anthony Lloyd Theodorou and published by . This book was released on 2008 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Bond Behavior of High volume Fly Ash and Self consolidating Concrete written by Trevor Jay Looney and published by . This book was released on 2012 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The main objective of this study was to determine the effect on bond performance of high-volume fly ash (HVFA) concrete and self-consolidating concrete (SCC). The HVFA concrete test program consisted of comparing the bond performance of two concrete mix designs with 70% cement replacement with Class C fly ash relative to a Missouri Department of Transportation (MoDOT) standard mix design. The SCC test program consisted of comparing the bond performance of normal and high strength SCC with their respective MoDOT standard mix designs. Two test methods were used for bond strength comparisons. The first was a direct pull-out test based on the RILEM 7-II-128 "RC6: Bond test for reinforcing steel. 1. Pullout test" (RILEM, 1994). The direct pull-out tests were performed on specimens with #4 (#13) and #6 (#19) deformed reinforcing bars. The second test method consisted of a full-scale beam splice test specimen subjected to a four-point loading until failure of the splice. This test method is a non-ASTM test procedure that is generally accepted as the most realistic test method for both development and splice length. The beam splice tests were performed on beams with #6 (#19) reinforcing bars spliced at midspan at a specific length to ensure bond failure occurs prior to shear or flexural failure. Analysis of the HVFA concrete data indicates that using greater than 50% replacement of cement with fly ash in concrete does not result in any increase in the required development length of mild reinforcing. Analysis of the SCC data indicates that using SCC does not result in any increase in the required development length of mild reinforcing"--Abstract, Leaf iii.

Download or read book Shear and Fracture Behavior of High volume Fly Ash Reinforced Concrete for Sustainable Construction written by Carlos Andres Ortega Ordonez and published by . This book was released on 2012 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete- concrete with at least 50% of the cement replaced with fly ash - offers a potential "green" solution. However, because it is still relatively new and has some disadvantages, there are still many questions that need to be answered. Most research to date has consisted only of the evaluation of the strength and durability of HVFA concrete mixtures, while only a limited number of studies have implemented full-scale testing of specimens constructed with HVFA concrete to determine its potential use in the industry. For this research, a laboratory testing program was developed to investigate the shear performance of reinforced concrete (RC) beams constructed with HVFA concrete. The experimental program consisted of 36 tests performed on full-scale RC beams. The principal parameters investigated were: (1) concrete type (HVFA or conventional concrete), (2) amount of shear reinforcement, and (3) amount of longitudinal (flexural) reinforcement. The full-scale beams in this study were analyzed using several different approaches, including the standard truss model, modified compression field theory, and fracture mechanics formulations. The full-scale test results were compared to the theoretical results using design approaches contained in several codes common to North America and Europe. The results indicate that existing design code provisions for conventional concrete are equally applicable to the design of HVFA concrete"--Abstract, leaf iii.

Download or read book Best Practices Guide for High Volume Fly Ash Concretes written by National Institute of Standards and Technology and published by CreateSpace. This book was released on 2014-02 with total page 70 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 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 take away messages 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 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 10th International Conference on FRP Composites in Civil Engineering written by Alper Ilki and published by Springer Nature. This book was released on 2021-11-26 with total page 2516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights the latest advances, innovations, and applications in the field of FRP composites and structures, as presented by leading international researchers and engineers at the 10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE), held in Istanbul, Turkey on December 8-10, 2021. It covers a diverse range of topics such as All FRP structures; Bond and interfacial stresses; Concrete-filled FRP tubular members; Concrete structures reinforced or pre-stressed with FRP; Confinement; Design issues/guidelines; Durability and long-term performance; Fire, impact and blast loading; FRP as internal reinforcement; Hybrid structures of FRP and other materials; Materials and products; Seismic retrofit of structures; Strengthening of concrete, steel, masonry and timber structures; and Testing. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among different specialists.

Download or read book Nanotechnology Applied to High Volume Fly Ash Concrete and Its Resistance to Freeze Thaw Damage written by Sen Du and published by . This book was released on 2020 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partially replacing cement with fly ash in concrete is an effective approach for reusing fly ash. High-volume fly ash (HVFA) concrete contains more fly ash than cement and exhibits many advantages including low hydration heat, low shrinkage, and reduced production cost. In this context, HVFA concrete has been successfully used in the field, such as mass concrete and structural concrete. However, some drawbacks are hindering its wider acceptance, including low early-age strengths and low freezing-thawing (F-T) resistance.This dissertation firstly optimizes the mix design of HVFA mortar through a statistical design of experiment, aimed at obtaining the best performance in the mechanical properties. In the HVFA system that adopted the optimized mix design, a hypothesis is proposed that approaches that can improve the transport properties, matrix's microstructure properties, and the interfacial transition zone (ITZ) properties could finally benefit the F-T resistance of HVFA concrete. Nanotechnology, including nanoscience and nanoengineering, is applied to investigate the hydration characteristics of fly ash and modify the F-T durability of HVFA concrete.For transport properties, some chemical admixtures are admixed into HVFA mortars, the dosages of which are optimized based on the performance of water sorptivity and mechanical properties. Pore structure at nanoscale and microscale are investigated based on its close relationship with transport properties. Graphene oxide (GO), as a promising nanomaterial in cement-based material, is added into HVFA concrete to enhance its microstructure. The modification mechanisms of GO on HVFA mixture are studied. Focusing on the ITZ, GO and nanosilica (NS)-contained paste slurry are applied to coat the coarse aggregate. The effectiveness of this approach is verified through images analysis. HVFA concretes with the best performance in the aforementioned three sections are subjected to further F-T testing. A four-phase sphere model is proposed for HVFA concrete to predict the change in dynamic modulus of elasticity during F-T cycles. Future research may include the life-cycle assessment of HVFA concrete in the context of employing nanotechnology. Besides, the F-T durability of HVFA concrete in the presence of deicers should be researched given the fact that more deicers are applied on concrete infrastructures.

Download or read book Fly Ash Facts for Highway Engineers written by William F. Boles and published by . This book was released on 1986 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 High Volume Mineral Admixtures in Cementitious Binders written by Dan Tsang and published by Elsevier. This book was released on 2024-09-07 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-Volume Mineral Admixtures in Cementitious Binders: Towards Carbon-Neutral Construction delivers an overview of the broad applications of high-volume supplementary cementitious materials (SCMs) in cementitious binders, addressing the most promising ways to use them to reduce carbon emissions in the construction and building industry. This book focuses on the applications and scientific challenges of high-volume SCMs blends, elaborating on the possibilities as well as offering original perspectives on using different kinds of blended cements in the manufacturing process. Emphasis is placed on activity estimation and quality assessment, the properties of high-volume SCM-blends at both the fresh and hardened stages, self-hydraulic properties, and potential use as the sole binder, as well as associated environmental impacts and carbon footprint reduction. Presents the macro-/microproperties of high-volume (SCMs) cements. Introduces the state of the art in the use of high-volume SCM cements. Discusses the associated environmental impacts and the contribution to carbon neutrality by using high-volume SCMs. Associated with the disposal of man-made waste in the production of building materials. Discusses the advantages of using waste materials in cement production which reduce environmental impacts and contribute to sustainable development.

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 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: