M35 grade of concrete was used for the present investigation. Abstract now a day, we need to look at a way to reduce the high that only rich people and governments can afford. Used in the right proportion it can also reduce the overall cost of the concrete. Silica fume, also known as microsilica, cas number 69012642, einecs number 2737611 is an amorphous noncrystalline polymorph of silicon dioxide, silica. Five different watercementitious ratios were used including, 0. Tests were performed on some 40 mixes made using silica fume as a replacement for cement in quantities of 15, 20, and 30 percent. In addition to its pozzolanic properties its is also a very good filler due to its particle size. It is an excellent for use as a portland cement supplement. Silica fume has become the world standard for chloride corrosion situations and also to improve dramatically the water tightness of concrete structures. It has many advantages and its advantages outweigh its disadvantages. Effect of silica fume on concrete properties and advantages.
Introduction silica fume can be used either as a densified or undensified powder, a slurry, as a combination at the concrete mixer, or part of a factoryblended cement. The efficiency of micro silica is 35 times that of opc and consequently vastly improved concrete performance can be obtained. Pandit3 concluded that addition of micro silica to concrete increases the strength more. Silica fume concrete transportation research board. Under hydrostatic pressure, other forms of waterproofing are required. Latexmodified and silica fume concrete overlays were placed on six bridges on i95 south of emporia, virginia, in the fall of 1994. The ability of high c3a cement to complex with chlorides results in the formation of insoluble compound, able to reduce the mobility of free chloride ion to the reinforcementconcrete surface. These bridge decks were monitored both during construction and after construction to evaluate their. Jan 26, 2017 silica fume concrete silica fume is an artificial pozzolona having high pozzolonic activity. For the silica fume to be effective, there are two issues. Comparison of artificial neural network and fuzzy logic models for prediction of longterm compressive strength of silica fume concrete j.
Verma7 found that silica fume increases the strength of concrete more 25%. In the wetmix process, the silica fume can be introduced as. It can be seen that the compressive strength development of concrete mixtures containing silica fume was negligible after the age of 90 days. Silica fume is much cheaper than cement therefore it is very important form economical point of view. One disadvantage is low early strength development than portland ceme. The exact addition rate depends upon on the specific performance characteristic to be improved. Silica fume is a material which may be a reason of air pollution this is a byproduct of some industries use. Stateoftheart report on highstrength concrete aci 363r92 reapproved.
For instance, it has higher compressive and flexural strength. Compared to the other ingredients in concrete, the amount of silica fume used is small. Silica fume created during silicon alloy production has a higher silica content, while silica fume produced as a result of manufacturing ferrosilicon alloys has a significantly lower silica content. The effect of silica fume only on concrete was give 61% increment in compressive strength, but with polymers together give about 72% increment, flexural strength increased from 3. Microsilica in concrete silica fume for sale, microsilica. Effect of micro silica on the strength of concrete with. Chapters 1 and 2 provide basic information explaining what silica fume is and how it is used in concrete. It is a by product from an electric arc furnace used in manufacture of silicon metal or silicon alloy. Explore silica fume with free download of seminar report and ppt in pdf and doc format.
This gaseous fume, as it rises, cools rapidly and forms extremely minute, amorphous, spherical particles. Concrete mix design in this experiment was designed as per the guidelines specified in aci234r 96 guide for the use of silica fume in concrete by aci committee 2347. The construction was funded with 20% virginia department of transportation maintenance funds and 80% special istea section 6005 federal funds specifically allocated to demonstrate overlay technologies. The efficiency of microsilica is 35 times that of opc and consequently vastly improved concrete performance can be obtained. Also explore the seminar topics paper on effect of cement replacement by silica fume and fly ash with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year civil engineering ce or ieee civil. A wide variety of silica fume concrete ppt options are available to you, there are 121 suppliers who sells silica fume concrete ppt on, mainly located in asia. As the molten metal is produced, a silica based gas is emitted. It is an ultrafine powder collected as a byproduct of the silicon and ferrosilicon alloy production and consists of spherical particles with an average particle diameter of 150 nm.
From the above literatures it is found that most of the researches were done using a small amount of nano sized mineral admixtures as an additive in a small amount in concrete. The durability of this type of concrete is superior to conventional concrete. Burnett csr days drying time microstrain 0 10203040 50607080 90 0 200 400 600 800 90 mpa 80 mpa 60 mpa figure 7 teamwork for silica fume high strength. Four silica fume concrete mixes with silica fume contents of 5%, 10%, 15%, and 20% of the total cementitious material content were prepared along with one plain portland cement concrete mix and. Fresh concrete containing silica fume is more cohesive and less prone to segregation than concrete without silica fume. Silica fume and kim media kryton international inc. The influence of silica fume on the compressive strength of. Adds cohesiveness and reduced bleeding improves strength and durability. The history of silica fume in concrete from novelty to key.
Microstructure analysis and strength properties of concrete. Concrete has a coefficient of thermal expansion and contraction of about 10 x. The use of silica fume in concrete has both engineering potential and economic advantage. Six fulldepth silica fume concrete bridge decks were constructed in minnesota between 1997 and 1999. Chemical admixtures for concreteaci 212 3r91 re,approved 1999 guide for the use of high range water reducing admixtures s u p e r plasticizers in concrete aci 212. The use of good quality fly ash with a high fineness and low carbon content reduces the water demand of concrete.
As the molten metal is produced, a silicabased gas is emitted. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. Silica fume has been recognized as a pozzolanic admixture that is effective in greatly enhancing mechanical properties. Silica fume, a byproduct of the ferrosilicon industry, is a highly pozzolanic material that is used to enhance mechanical and durability properties of concrete. Fresh concrete containing silica fume is more cohesive and less. Guide for silica fume in concrete aci 234r96 reapproved 2000. Through his employment at elkem hes been directly involved with silicafume concrete research and implementation into project applications for the past 20 years. Apr 08, 2017 effect of fly ash and silica fume on concrete properties.
It may be added directly to concrete as an individual ingredient or in a blend of portland cement and silica fume. Effect of silica fume on mechanical properties of high. This alternative is a fulldepth silica fume concrete bridge deck. Apr 26, 20 the influence of silica fume sf addition on properties of geopolymer materials produced from alkaline activation of aluminosilicates metakaolin and waste concrete produced from demolition works has been studied through the measurement of compressive strength, fourier transform infrared spectroscopy, xray diffraction, and scanning electron microscopy sem analysis. Different chapters of the manual may be of interest to concrete specifiers, concrete producers, concrete contractors, or concrete inspectors. The effects of utilizing silica fume in portland cement pervious concrete daniel allen mann, candidate for the master of science degree university of missourikansas city, 2014 abstract silica fume has long been used as a supplementary cementing material to provide a high density, high strength, and durable building material.
Once again, this cohesiveness is due to its fine particle content. Properties of silica fume related to its applications. Fly ash, slag, silica fume, and natural pozzolans fly ash, ground granulated blastfurnace slag, silica fume, and natural pozzolans, such as calcined shale, calcined clay or metakaolin, are materials that, when used in conjunction with portland or blended cement, contribute to the properties of the hardened concrete through hydraulic or. Guide to using silica fume in precastprestressed concrete. Silica fume seminar report, ppt, pdf for civil engineering. Silica fume is much cheaper then cement therefore it very important form economical point of view.
These combined properties lead to an extended life expectancy in corrosive environments resistance to chlorides, acids and sulphates and improved strength. Micro silica or silica fume is very fine non crystalline material. Astm c1240 20 standard specification for silica fume used. Silica fume on the properties of concrete as defined in concrete society report 74, cementitious materials des king hon. A wide variety of silica fume concrete ppt options are available to you, there are 121 suppliers who sells silica fume concrete ppt. Silica fume for highperformance concrete silica fume, or microsilica, is a pozzolanic material that reacts with the free lime in concrete to form calciumsilicate hydrates csh. Investigations on microsilica silica fume as partial cement. His aci duties include secretary of the silicafume concrete subcommittee, and chapter author to the highstrength concrete, parking structures, and concrete proportioning committees. Fly ash, slag, silica fume, and natural pozzolans, chapter 3. Microsilica in concrete microsilica is a byproduct from silicon metal or ferrosilicon industries, where these metals are produced in submerged electric arc furnaces. The concrete was to exhibit superior durability characteristics when exposed to freezethaw, as well as resistance to other deleterious effects such as scaling. If the silica fume concrete contains superplasticizers, both the shear resistance and the cohesiveness of the concrete will be reduced, and improved flow will result. Silica fume and metakaolin admixtures are formulated to produce extremely strong and durable concrete.
Introduction silica fume can be used either as a densified or undensified powder, a slurry, as a combination at the. Use of microsilica as additive to concretestate of art. Silica fume concrete with an hrwr is more cohesive and sticky than conventional concrete. The ability of high c3a cement to complex with chlorides results in the formation of insoluble compound, able to reduce the mobility of free chloride ion to the reinforcement concrete surface. Silica fume has come in common use in a majority of industrial countries and many developing countries silica fume has since long been an international tradeable product it is estimated that over 10 million m3 silica fumecontaining concrete is cast every year whereas the early years had a focus on silica fume as cement. Fogging the air above the concrete and erecting windshades lessen the risk of plasticshrinkage cracking. Even though silica fume densifies concrete, it is not a waterproofer. Silica fume concrete is composed of cement, silica fume, fine aggregate, coarse aggregate, and water.
Silica fume is a very common scm that is frequently used to increase the strength and durability of a concrete structure. The use of silica fume in concrete should be limited to specialized applications that can take full advantage of its unique properties. Silica fumes behavior in concrete is predictable, but still dictated by the materials composition. Fresh and hardened properties of silica fume concrete is superior to conventional concrete. Provided silica fume high strength concrete is cured for 24hrs shrinkage is likely to be similar or less than normal concrete. Investigations on microsilica silica fume as partial cement replacement in concrete. Silica fume, cstr74, properties of concrete, effects, cementitious materials, high performance concrete. Silica fume is not a new product by one company but is a major raw material that has been available over 40 years. The pozzolanic reaction cannot begin before the reaction between the cement and water has started.
Additionally, silica fume reduces bleeding by physically blocking the pores in the fresh concrete. Silica fume increases the strength of concrete more 25%. Fict, dip m, chartered mcim, dms consultant, united kingdom keywords. Figure 6 shrinkage of silica fume high strength concrete. What are the disadvantages of silica fume in concrete. The silica react rapidly providing high early age strength and durability. Department of civil engineering, north eastern regional. Fly ash increases workability when compared with conventional concrete with same water content. Silica fume reduces the permeability of the concrete. Concrete containing silica fume shows substantial reduced bleeding. When used to produce highperformance concrete, silica fume is typically 415% of the cement weight. Silica fume concrete silica fume for sale, microsilica. Effect of cement replacement by silica fume and fly ash.
The use of silicafume microsilica additions to improve the compressive strength and durability of concrete is becoming widespread. Explore effect of cement replacement by silica fume and fly ash with free download of seminar report and ppt in pdf and doc format. Apr 16, 2016 silica fume is a pozzolanic material that is used with portland cement to produce portland pozzolana cement. Also explore the seminar topics paper on silica fume with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year civil engineering ce or ieee civil construction btech, be, mtech students for the year 2017 2018. The use of silica fume concrete for fulldepth bridge deck. The addition of silica fume to concrete improves the latters durability by reducing permeability and refining pore structure, leading to a reduction in the diffusion of harmful ions and the calcium hydroxide content, resulting in greater resistance to sulfate attack. Bureau of reclamation engineering and research center denver, co 80225 0 11. Properties of silica fume the physical and chemical properties of silica fume visavis, opc are presented in table 1. Pdf effect of silica fume on workability and compressive.
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