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. Barriers to the use of high volume fly ash hvfa concrete and the need for more research into this type of concrete are discussed. 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. Barriers to the use of high volume fly ash hvfa concrete and the need for more research into this type of concrete. 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. One major issue with the widespread usage of concrete with high volume fly ash is that the resulting concrete. Use of high volumes of fly ash in concrete is gaining significance and is considered as a sustainable. Fly ash based specifies that the fly ash constituent in portlandpozzolana cement shall not be less than 10 percent and not more than 25 percent by mass of portlandpozzolana cement. High volume fly ash concrete mixtures when properly cured, are able to provide excellent watertightness and durability. Chapter 3 fly ash in portland cement concrete fly ash. Hvfa concrete has many benefits, including reduced concrete. 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.
Increasing the amount of fly ash in concrete is not without shortcomings. The balance amount of fly ash is being stored in fly ash. Concrete mixtures with fly ash as 30% and 40% of total binder were used to cast the test specimens. 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. May 21, 2014 this paper reports the results of an experimental study on durability of ordinary concrete and high volume fly ash hvfa concrete containing nano silica ns. Experimental study on performance of high volume fly ash concrete. A total of eight concrete mixtures with and without fly ash was investigated. Durability properties of high volume fly ash concrete. Experimental study on performance of high volume fly ash. Center for innovative grouting material and technology cigmat department of civil and environmental engineering university of houston, houston, texas 772044003 phone. Development of high volume fly ash cements for use in. Properties of highvolume fly ash concrete incorporating. 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 type of concrete is known as high volume fly ash concrete and this concrete produces mixtures that show high workability, high ultimate strength, and high durability.
If greenness is important, then there is good reason to use as much fly ash. Fly ash is considered as a hazardous waste due to leaching of toxic substances into the ground water and soil when it is disposed into ponds, lagoons etc or used as a land fill. Concrete produced with high fly ash replacement levels is considered high volume fly ash hvfa concrete. Fly ash is a waste product generated by coal burning power plants. The purpose of the project is to evaluate the concept of using relatively large volumes of fly ash in normal portland cement concrete, and hence enhance the beneficial use of fly ash in valueadded products and construction. The compressive strength, drying shrinkage, sorptivity and rapid chloride. And is the relationship between test specimens and in situ concrete. Engineered cementitious composites with highvolume fly ash. Project application of high volume fly ash concrete. When fly ash is added to concrete, the amount of portland cement may be reduced. Mechanical properties of high volume fly ash hvfa and concrete subjected 245 3.
Properties of highvolume fly ash concrete incorporating nano. These problems can be avoided with increased use of fly ash. Fly ash concrete is an ecofriendly construction material in which fly ash. Engineered cementitious composites with high volume fly ash aci materials journal, aci material. This paper reports the effects of incorporating high volume fly ash in fiber reinforced concrete. 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. Performance of highvolume fly ash concrete in marine. Durabilty and strength properties of high volume fly ash concrete. Sustainability, performance and mix design of high volume fly. Highvolume fly ash concrete university of wisconsin.
Rcc is a special form of concrete for construction of dams and pavements 14. Pdf concrete durability through high volume fly ash. Pdf performance of high volume fly ash in concrete structures. This paper looks at high volume percentage replacements from 40 to 70%. Concrete is the worlds most consumed manmade material. 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. However, the high volume fly ash hvfa system, discussed next, represents an emerging technology for producing sustainable hpc mixtures. Performance of high volume fly ash concrete in marine environment. Tennessee technological university, box 5015, cookeville, tn 38505. Pdf on jan 1, 20, indubhushan patnaikuni and others published high strength high volume fly ash concrete. A best practices guide is developed from a synthesis of recent research on high volume fly ash \hvfa\ concrete mixtures.
Keyword high volume fly ash concrete, curing, mix design, compressive strength. International workshop on sustainable development and concrete technology. With high volume fly ash concrete, you will see less early age strength, but the long term strength is about the same as with normal concrete. Th is article addresses some optimal ways of specifying. High volume high performance fly ash for leed concrete emrah demircan, c. This paper presents the durability performance of concrete incorporating high volumes of fly ash exposed to a harsh. Greatly increased use of fly ash in hydraulic cement concrete. 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. Mix proportions and further data for the strength of very high volume fly ash concrete. The inferior durability characteristics of concrete may be. Concrete in general and fly ash concrete in particular with 50% or more high volume replacements can experience brittle behavior.
American concrete institute aci manual of concrete practice, section 211. Deo, assistant professor, national institute of technology. The mechanisms by which the incorporation of high volume of the ash in concrete. China and india, this technology can play an important role in meeting the huge. Crouch1, ryan hewitt1, ben byard1 1 tennessee technological university, box 5015, cookeville, tn 38505 keywords.
Any concrete that uses more fly ash than 25% weight of cement would be considered high volume fly ash concrete. The fibers were polypropylene or steel fibers at a maximum proportion of 1% by volume of the concrete. 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. 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. National institute of standards and technology technical note 1812. Using fly ash in concrete is environmentally beneficial because it reduces the portland cement a major contributor of co2 required in concrete.
Reducing the risk of cracking in high volume fly ash concrete by using internal curing. Use of highvolume fly ash concrete hvfac has to be. Characterization of the behavior of high volume fly ash. Pdf highvolume, ultralowdensity fly ash foamed concrete. Unused quantities of fly ash create landfill and environmental problems. Greatly increased use of fly ash in hydraulic cement. K2 associate professor, college of engineering, trivandrum, kerala, india. Fly ash is a byproduct from the combustion of pulverized coal, and is widely used as an ingredient in hydrauliccement 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. Pdf development and evaluation of highvolume fly ash. Carbonation resistance of high volume fly ash concrete. Powder diffraction file pdf, and these were used to identify compounds, by. High volume high performance fly ash for leed concrete. Fly ash replacement was examined at 50% and 70% replacement by total cementitious mass.
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. 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. The influence of high volume fa cements on strength development of concrete was tested using concrete cubes 100 mm cured in both water at 20 c and air at 20 c and 55% rh. A study on high volume fly ash concrete exposed to. Pdf the application of concrete in construction is as old as the days of greek and roman civilization. Fly ash produced in such way has high content of sio2 and low content of cao, and it is ranked among cocalled siliceous fly ash, which has outstanding pozzolanic properties. In normal fly ash concrete, the ash replacement for cement is usually in range of 1025%.
To increase its percentage utilization, an extensive investigation was carried out to use it. It is proposed, therefore, to manufacture a concrete with high volume of fly ash, low cement content and high service life period. Fly ash is commonly used as a supplementary cementitious material scm in the production of portland cement concrete. Effect of fly ash on the durability properties of high. Unfortunately, the production of portland cement, the active ingredient in concrete, generates a significant amount of carbon dioxide. Using highvolume flyash concrete concrete construction. 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. More than 88 million tons of fly ash is generated in india each year. The use of concrete containing high volumes of fly ash hvfa has recently gained. Because it improves many desirable properties of concrete, it is introduced either as a separately batched material or as a component of blended cement. 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. As per the definition given by mehta 10, a concrete having minimum cement replacement level of 50% by fly ash is termed as high volume fly ash concrete hvfac.
Pdf experimental study on performance of high volume fly. Case study 21 page 2 of 5 high volume use of high carbon fly ash for highway construction unlike concrete, which needs airentrainment generally 6% air by volume, extra voids are not. Highvolume fly ash concrete technology technical report. Sustainability, performance and mix design of high volume. Using the experimental data, a column section is designed. In this context, an experimental campaign was developed with the aim of characterization of pastes behavior with high fly ash. 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. This report is primarily concerned with the literature information on high volume fly ash concrete.
Variable of the test program includes replacement of cement with fly ash from 30% to 50%, temperatures from 27oc to 800oc at an interval of 200oc for 3 hours duration. 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. Mechanical properties of high volume fly ash concrete. In this study, concretes containing 2 and 4 % of ns are prepared at a constant waterbinder ratio of 0.
Three powder activators were used in combination with the cement and fly ash mixtures. Ongoing advancements in the concrete technology have set up new courses for enhancing the mechanical and durability properties of concrete. However, the highvolume fly ash hvfa system, discussed next, represents an emerging technology for producing sustainable hpc mixtures. The factors analyzed are type of fly ash, kind of mixing. This is the turnerfairbank highway research center. Is there a greater sensitivity to changes in ambient conditions with hvfa. Concrete containing more than 50% of fly ash content by mass of the total cementitious materials is considered as high volume fly ash concrete hvfac. The factors analyzed are type of fly ash, kind of mixing water. 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. Development of highvolume high temperature fly ash concrete.
Fly ash concrete is an ecofriendly construction material in which fly ash replaces a part of portland cement. A study on high volume fly ash concrete exposed to elevated. 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 volume fly ash hvfa concrete mixtures offer many benefits, including reduced cost, reduced energy content, enhanced. Malhotra observed significant improvement in strength and durability with the substitution of high volume class f fly ash in ordinary portland cement opc. Ramkrishnan et al have developed an sn relation for hvfac with cement replacement level of 58% using. Chapter 3 fly ash in portland cement concrete fly ash facts for. High volume fly ash concrete is a modified concrete that has many benefits compare to ordinary portland cement concrete. Optimizing the use of fly ash in concrete portland cement.
Mix proportions and mechanical properties of concrete. 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. Literature shows incorporation of high volumes of fly ash that is, 5080% is possible in roller compacted concrete rcc 11. The use of fly ash in portland cement concrete pcc has many benefits and improves concrete performance in both the fresh and hardened state. High volume fly ash concrete is an alternative where 5070% replacement. This is because fly ash is a lesser activity pozzolanic material. High volume fly ash concretebasics building excellence.
In spite of that, the actual use of high volumes of fly ash 30% of total cementitious materials content in ready mixed concrete is limited. I have heard about the greater influence temperature has on strength development with high volume fly ash concrete, but i can find little in the way of quantifiable data. Reducing the risk of cracking in high volume fly ash. Thermal properties of highvolume fly ash mortars and. International journal of research in electronics vol.
In this study, durability properties of high strength concrete utilizing high volume class f fly ash sourced from western australia have been investigated. 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. Cement concrete and fly ash based concrete has been made. This paper describes experience from experimental development of high volume fly ash concrete hvfac, where over 50% of fly ash is used as substitution of portland cement. In recent years, an emerging technology known as highperformance highvolume fly ash hvfa concrete has become available, which incorporates large volumes of.
Extending the usage of high volume fly ash in concrete. Effects of high volume fly ash and powder activators on. The study discloses that high volume of fly ash in concrete. Strength and behaviour of high volume fly ash concrete mini soman1 sobha. Mix design approach for high 28 days strength, highvolume, low. Fly ash is used in various proportions ranging from 10% to 50% by weight of cement in steps of 5%. 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. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes. Ash concrete, and its role in sustainability of cement and concrete. The physical and mechanical properties studied are residual compressive. Results and discussion temperature is one of the main factors that influence the strength. New technologies and procedures to address unburned carbon in fly ash are. Fly ash use in concrete improves the workability of plastic concrete, and the strength and durability of hardened concrete. Pdf wear resistance of highvolume fly ash concrete.
Suitable raw materials and mix proportion were chosen. 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. This paper reports an analysis of three factors in mix proportion of high volume fly ash concrete to produce high strength concrete. Currently, fly ash is used in more than 50% of all ready mixed concrete placed in the united states, yet many design professionals continue to remain overly restrictive when it comes to using fly ash in concrete. Best practices guide for highvolume fly ash concretes. Afe disposal of fly ash is a growing problem in india. Unfortunately, the production of portland cement, the active ingredient in concrete, generates a significant amount of carbon. Best practices guide for highvolume fly ash concretes cement. This report presents technical information to support the use of high volume fly ash concrete for structural applications. The advantages and limitations of high volume fly ash concrete. For each pound of cement produced, approximately one pound. With rising fly ash production more efforts must be put on higher consumption of fly ash. The relative cost of column section designed with opc as well as various proportion of fly ash is estimated and compared. Engineered cementitious composites with high volume fly ash.
Strength and behaviour of high volume fly ash concrete. Experimental investigation on high volume fly ash concrete. Mechanical properties of high volume fly ash hvfa and. The author also wishes to acknowledge the assistance of the technical staff, in. Bond strength of highvolume fly ash concrete by michael hayse wolfe a thesis presented to the faculty of the graduate school of the missouri university of science and technology in partial fulfillment of the requirements for the degree master of science in civil engineering 2011 approved by dr. High volume fly ash concrete is a concrete where a replacement of 50 to 60 percentage of. Limited studies 11 are available on fatigue behavior of hvfac. Design and mix proportioning of green concrete using 100% fly ash based hydraulic binder duration. Research article strength properties of high workable and.
In addition to providing an indication of the mineralogy and reactivity of the fly ash. There is a large body of research and literature46 on the development and use of high volume fly ash hvfa concrete. There is a large body of research and literature on the development and use of high volume fly ash hvfa concrete. High volume flyash concrete, international journal of civil engineering and. Pdf high strength high volume fly ash concrete researchgate. These best practices can be applied by the concrete construction industry to achieve desired properties and ensure the \ high \ perf\ ormance of hvfa concrete. Dec, 2016 high volume fly ash concrete is a modified concrete that has many benefits compare to ordinary portland cement concrete. 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.