Performance of highvolume fly ash concrete in marine. Concrete is the largest market for fly ash and offers the highest potential for increased flyash utilization. After short time curing, there is a number of unhydrated fly ash in high volume fly ash cement system, and the addition of fly ash in concrete leads to higher porosity and larger pore size. N2 although fly ash as a partial replacement for cement has been utilized for many years, it has been almost exclusively used in low volume percentages, such as 10 or 20% cement replacement.
High performance concrete, self com pacting concrete an d the latest in the series is high volume fly ash concrete hvfc. While fly ash is routinely used in concrete, the actual use of high volumes of fly ash 30% of. This report presents technical information to support the use of high volume fly ash concrete for structural applications. This paper presents the durability performance of concrete incorporating high volumes of fly ash exposed to a harsh marine environment for 19 to 24 years. A study on high volume fly ash concrete exposed to. In this paper, m 40 grade is prepared with high volume fly ash in concrete with various proportions as a partial replacement of cement and m sand is used 100% replacement as fine aggregates. In this paper, mechanical and durability properties of hvfac are studied. Five mix designs were compared with varying fly ash percentages from 0 to 70% by total cementitious mass. Fly ash concrete slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Testing and materials astm to allow high volume fly ash hvfa concrete to cure until later ages prior to testing instead of 28 days. Barriers to the use of high volume fly ash hvfa concrete and the need for more research into this type of concrete are discussed. Selfconsolidating concrete scc and highvolume fly ash concrete hvfac for infrastructure elements.
Sustainability, performance and mix design of high volume. Selfconsolidating concrete scc and high volume fly ash concrete hvfac for infrastructure elements. Effect of fly ash on strength of concrete springerlink. Performance of high volume fly ash concrete in marine environment. Fly ash in concrete a literature study of the advantages and. Because of the sheer volume of concrete used on a project, a small increase in fly ash replacement can translate into a big impact on the total recycled content. Optimization of particle sizes in high volume fly ash blended. Fly ash fits the definition of postindustrial waste. Tennessee technological university, box 5015, cookeville, tn 38505. Pdf concrete durability through high volume fly ash. High volume fly ash concrete fly ash, a principal byproduct of the coalfired power plants, is well accepted as a pozzolanic material that may be used either as a component of blended portland. To increase its percentage utilization, an extensive investigation was carried out to use it.
The factors analyzed are type of fly ash, kind of mixing water. Concrete produced with high fly ash replacement levels is considered high volume fly ash hvfa concrete. Characterization of the behavior of high volume fly ash. High volume high performance fly ash for leed concrete. Optimizing the use of fly ash in concrete portland cement. Fly ash is a byproduct from coalfired power plants that is frequently used as an admixture in concrete to replace a portion of the portland cement. Crouch1, ryan hewitt1, ben byard1 1 tennessee technological university, box 5015, cookeville, tn 38505 keywords. Pdf experimental study on performance of high volume fly. Deo, assistant professor, national institute of technology.
It has a higher percentage of calcium oxide than class f and is more commonly used for structural concrete. Mechanical properties of high volume fly ash concrete. Sustainability, performance and mix design of high volume fly. Index evaluation of highvolume fly ash mixtures paste and.
Carbonation resistance of high volume fly ash concrete. Highvolume fly ash concrete technology technical report. Experimental study on performance of high volume fly ash concrete. Project application of high volume fly ash concrete.
In this context, an experimental campaign was developed with the aim of characterization of pastes behavior with high fly ash content, in particular with respect to its durability. One major issue with the widespread usage of concrete with high volume fly ash is that the resulting concrete is not durable from salt scaling during freezing. This is because fly ash is a lesser activity pozzolanic material. Effect of fly ash on the durability properties of high. With more than four decades of experience marketing fly ash to the concrete industry, boral is a pioneer in the development of new construction material technologies. Reducing the risk of cracking in high volume fly ash.
International journal of recent technology and engineering ijrte. These best practices can be applied by the concrete construction industry to achieve desired properties and ensure the \ high \ perf\ ormance of hvfa concrete mixtures in practice. By means of fly ash in concrete in place of cement reduces the consumption of natural resources, diminishes the environmental pollution and also economical as replacing the cement which is costlier by the fly ash. Dec, 2016 high volume fly ash concrete is a modified concrete that has many benefits compare to ordinary portland cement concrete. The study discloses that high volume of fly ash in concrete reduces.
High volume fly ash concrete is a concrete where a replacement of 50 to 60 percentage of. The paradigm has sh ifted from one property to other of c oncrete with. Introduction fly ash, one of the most commonly used pozzolanic material for cement replacement, gained. Pdf development and evaluation of highvolume fly ash. Boral resources is a leading marketer of fly ash and all coal combustion products. It is proposed, therefore, to manufacture a concrete with high volume of fly ash, low cement content and high service life period. In this study, durability properties of high strength concrete utilizing high volume class f fly ash sourced from western australia have been investigated. Concrete in general and fly ash concrete in particular with 50% or more high volume replacements can. Best practices guide for highvolume fly ash concretes. Fly ash is a wastebyproduct which gives a challenge to the environment. More than 88 million tons of fly ash is generated in india each year. It is widely recognized that high volume fly ash hvfa concrete is capable of producing concrete with satisfactory strength and long term durability in a number of environments. Pdf high strength high volume fly ash concrete researchgate. The fresh and hardened properties of high volume fly ash concrete hvfac with 50% replacement of cement and ordinary portland cement concrete opcc are studied.
The compressive strength, drying shrinkage, sorptivity and rapid chloride. Concrete is the worlds most consumed manmade material. The inferior durability characteristics of concrete may be. In some cases, fly ash can add to the concrete s final strength and increase its chemical resistance and durability. Benefits of high volume fly ash new concrete mixtures provide financial, environmental, and performance gains.
Class c fly ash is typically composed of high calcium fly ashes with a carbon content of less than 2 percent. National institute of standards and technology technical note 1812. Thermal properties of highvolume fly ash mortars and concretes. For each pound of cement produced, approximately one pound. Unfortunately, the production of portland cement, the active ingredient in concrete, generates a significant amount of carbon dioxide. In recent years, an emerging technology known as highperformance highvolume fly ash hvfa concrete has become available, which incorporates large volumes of fly ash into conventional portland cement concrete. Durabilty and strength properties of high volume fly ash concrete. High volume fly ash hvfa cement and concrete directly serve this highly useful beneficial cause. By replacing 50 % or more of the portland cement with fly ash, a significant reduction is achieved in the carbon footprint of the in place concrete. Recently, techniques have been developed to replace partial cement with high volume fly ash. Jul 17, 2017 fly ash is a byproduct from coalfired power plants that is frequently used as an admixture in concrete to replace a portion of the portland cement.
The more fly ash that is used in the concrete, the higher the percentage of total postindustrial waste on the project. Recently, techniques have been developed to replace partial cement with high volume fly ash 50% cement replacement. C40r60 high volume fly ash hvfa concrete were adopted for the continuously casting massive foundation slab of tianjin tower, which has a volume of about 20 000 m3, to decrease the risk of cracking during the construction process. Fly ash can significantly improve the workability of concrete. Santhakumar a r 2008 concrete technology, oxford university press, new delhi. Using fly ash in concrete is environmentally beneficial because it reduces the portland cement a major contributor of co2 required in concrete. Experimental investigation on high volume fly ash concrete. High volume fly ash concrete fly ash, a principal byproduct of the coalfired power plants, is well accepted as a pozzolanic material that may be used either as. Index evaluation of highvolume fly ash mixtures paste. Experimental study on performance of high volume fly ash. Pdf on jan 1, 20, indubhushan patnaikuni and others published high strength high volume fly ash concrete. Fly ash is commonly used as a supplementary cementitious material scm in the production of portland cement concrete. High volume fly ash concrete can be used in a variety of structural applications. China and india, this technology can play an important role in meeting the huge.
Powder diffraction file pdf, and these were used to identify compounds, by. Fly ash is a byproduct from the combustion of pulverized coal, and is widely used as an ingredient in hydrauliccement concrete. Fly ash reacts with the hydrating hydraulic cement to form a cementing medium. This paper reports the development a low embodied carbon dioxide backfill material based on an ultralowdensity foamed concrete using a high volume of fly ash to replace portland cement. A study on high volume fly ash concrete exposed to elevated. An enormous amount of fly ash is generated in thermal power plants in india, which affects the environment and living organism. Because it improves many desirable properties of concrete, it is introduced either as a separately batched material or as a component of blended cement. Replacement of cement with 55%, 65%, 75%, and 85% fly ash was carried out to evaluate the.
The mechanisms by which the incorporation of high volume of the ash in concrete reduces the water demand, improves the workability, minimizes cracking due to thermal and drying shrinkage, and. Mix proportions and mechanical properties of concrete. Autogenous shrinkage and residual tensile stress are reduced in high volume fly ash mixtures with internal curing. High volume fly ash concrete is a modified concrete that has many benefits compare to ordinary portland cement concrete. If the calcium content of the fly ash is high enough, it is possible to make concrete with moderate strength using the fly ash as the sole cementing material cross 2005. In this study, high volume fly ash concrete with 70% fly ash as replacement for cement with appropriate chemical admixtures, was investigated. Even though ready mixed concrete forms the single largest market for fly ash it can still offer the largest potential for increased fly ash utilization. Although fly ash as a partial replacement for cement has been utilized for many years, it has been almost exclusively used in low volume percentages, such as 10 or 20% cement replacement.
The balance amount of fly ash is being stored in fly ash. High volume fly ash hvfa concretes are one component of creating a more sustainable infrastructure. Best practices guide for highvolume fly ash concretes cement. Readymix concrete producers and contractors improve their operations with the aid of borals. Selfconsolidating concrete scc and highvolume fly ash. It has been proven as a technology that can accommodate sustainable development and improve the lifespan and performance of structures. Malhotra observed significant improvement in strength and durability with the substitution of high volume class f fly ash in ordinary portland cement opc.
Strength and behaviour of high volume fly ash concrete. The fibers were polypropylene or steel fibers at a maximum proportion of 1% by volume of the concrete. A best practices guide is developed from a synthesis of recent research on high volume fly ash \hvfa\ concrete mixtures. The main mechanical properties of high volume fly ash hvfa and concrete subjected 243 parameters studied were compressive strength, split tensile strength, modulus of. Mixture proportioning options for improving high volume fly. Properties of highvolume fly ash concrete incorporating nano. Typically in these mixtures, fly ash can replace 50 % or more of the portland cement, reducing cement consumption and the co2 emissions accompanying its production, on a per volume unit of concrete basis. According to some researchers, more than 30% fly ash by mass equivalent as 50% by volume of the cementitious material may be considered enough to classify the mixtures as high volume fly ash hvfa concrete. Pdf performance of high volume fly ash in concrete structures. Concrete for sustainable development, international workshop on sustainable development and concrete technology. Oct 31, 2016 high volume fly ash concrete is a concrete where a replacement of about 35% or more of cement is made with the usage of fly ash. While high volume fly ash concrete can be proportioned to produce durable concrete, its use is not without problems. Other benefits of fly ash in concrete include resistance to corrosion of concrete reinforcement, attack from alkalisilica reaction, sulfate attack and acids and salt attack. High volume fly ash scc of grade m30 satisfying efnarc guidelines in fresh state was designed using nansu method of mix design.
Strength and behaviour of high volume fly ash concrete mini soman1 sobha. Concrete mixtures with fly ash as 30% and 40% of total binder were used to cast the test specimens. There is a large body of research and literature46 on the development and use of high volume fly ash hvfa concrete. This is the turnerfairbank highway research center. Greatly increased use of fly ash in hydraulic cement. Optimization and development of highstrength highvolume fly. Highvolume fly ash concrete fly ash, a principal byproduct of the coalfired power plants, is well accepted as a pozzolanic material that may be used either as a component of blended portland. Fly ash concrete is an ecofriendly construction material in which fly ash replaces a part of portland cement. However, the high volume fly ash hvfa system, discussed next, represents an emerging technology for producing sustainable hpc mixtures.
The canada centre for mineral and energy technology. Concrete technologists utilized high volume fly ash concrete in their research. Uses, benefits, and drawbacks of fly ash in construction. Technology ntnu research partner and industry partners, 15 20. The advantages and limitations of high volume fly ash concrete are discussed, and the characteristics of the fresh and hardened materials and the durability of the material to various aggressive environments are covered. This paper presents a laboratory study on the properties of high volume fly ash high strength concrete incorporating nanosio 2 shfac. Properties of highvolume fly ash concrete incorporating.
Concrete in general and fly ash concrete in particular with 50% or more high volume replacements can experience brittle behavior. Concrete is the largest market for fly ash and offers the highest potential for increased fly ash utilization. Suitable raw materials and mix proportion were chosen. K2 associate professor, college of engineering, trivandrum, kerala, india. High volume fly ash concretebasics building excellence. A research project is being carried out at the center for byproducts utilization, uwmilwaukee on structural grade concrete containing low cement and high volumes of fly ash. A technical analysis for compressive strength dr s l pati1 1, j n kale 2. There is an increase of compressive strength to the specimens made of high volume fly ash concrete at 90 days of curing.
Large volume of fly ash is being produced by thermal power stations and part of the fly ash produced is used in concrete industry, low laying area fill, roads and embankment, brick manufacturing etc. This document is a technical summary of the unpublished federal highway administration fhwa report, evaluation of highvolume fly ash hvfa mixtures paste and mortar components using a dynamic shear rheometer dsr and an isothermal calorimeter, available through the national technical information service ntis. Some issues include slow strength gain at early ages, delayed setting, and reduced bleeding that results in extended curing time requirements and eventually slows down concrete paving during construction. The properties of hardened concrete cured under different conditions. The results show that the compressive strength of high volume fly ash concrete at 28 days is lower when compared to the compressive strength of conventional concrete specimens. Pdf highvolume, ultralowdensity fly ash foamed concrete. Mix proportions and further data for the strength of very high volume fly ash concrete are provided for reference. However, the highvolume fly ash hvfa system, discussed next, represents an emerging technology for producing sustainable hpc mixtures. Fly ash reacts with the hydrating hydraulic cement to form a.
High volume fly ash hvfa concrete mixtures offer many benefits, including reduced cost, reduced energy content, enhanced environmental sustainability, and improved longterm performance. The results of this research show that high volume fly ash mixtures with internal curing provided sufficient earlyage strength compared to a typical concrete bridge deck mixture design. High volume fly ash concrete is a concrete where a replacement of about 35% or more of cement is made with the usage of fly ash. Fly ash was mixed as a partial fine aggregate replacement of approximately one third of the fines volume.
Ongoing advancements in the concrete technology have set up new courses for enhancing the mechanical and durability properties of concrete. Class c fly ash is also resistant to expansion from chemical attack. This paper looks at high volume percentage replacements from 40 to 70%. Using highvolume flyash concrete concrete construction. The results were compared with those of control portland cement concrete pcc and of high volume fly ash high strength concrete hfac. Fly ash, high volume, concrete, durability, strength. Hvfa concrete has many benefits, including reduced concrete production cost, reduced greenhouse gas. This report is primarily concerned with the literature information on high volume fly ash concrete. This study was conducted to assess the feasibility that a fly ash concrete with moderate and high strength can be produced using very high volume of up to 80% of class f fly ash as cement replacement.
Index terms high volume fly ash concrete, high strength concrete, high. Ash technology and marketing, london, ash marketing, cegb. This paper reports the effects of incorporating high volume fly ash in fiber reinforced concrete. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes. Fly ash is a waste product generated by coal burning power plants. This paper reports an analysis of three factors in mix proportion of high volume fly ash concrete to produce high strength concrete.
High volume fly ash concrete mixtures when properly cured, are able to provide excellent watertightness and durability. Mechanical properties of high volume fly ash hvfa and. High volume flyash concrete, international journal of civil engineering and. In addition to providing an indication of the mineralogy and reactivity of the fly ash, the calcium content is also useful in predicting how effective. High volume fly ash concrete is an alternative where 5070% replacement.
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