Silica fume is stored and handled similar to cement or fly ash. The effect of using silica fume on the workability of concrete due to addition of silica fume was measured by taking the slump of the concrete produced with and without silica fume. Combine effect of silicafume, flyash and steel fibre on reinforced. Concrete, silica fumemicro silica, compressive strength, density. Just click on the pdf icon above and you will be directed to a login page. 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. Silica fume, also known as microsilica, cas number 69012642, einecs number 2737611 is an amorphous noncrystalline polymorph of silicon dioxide, silica. Comparative study of the characteristics of nano silica. Silica fume concrete is composed of cement, silica fume, fine aggregate, coarse aggregate, and water. Silica fume, a byproduct in the manufacture of ferrosilicon and also of silicon metal, is a very efficient pozzolanic material, though there are some problems associated with its use in concrete. The exposure limit is calculated from the equation, 80 %sio2, using a value of 100% sio2. Silica fume technical information red industrial products.
Research in the late 1960s showed that the use of silica fume microsilica as a partial replacement for cement in concrete mixes produced a dense concrete with properties su perior to those of ordinary portland cement concrete. 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. Silica fume material safety data sheet elkon products. Figure 2 silica fume reacts with the weak leachable caoh. Fa and sf enhance mainly the longterm strength and durability properties of cement composites owing to their pozzolanic reactions with calcium hydroxide formed during. The use of silica fume in concrete should be limited to specialized applications that can take full advantage of its unique properties. Figure 4 approximately 100,000 silica fume silica fume particles fill the space between cement grains. For instance, it has higher compressive and flexural strength. Explore silica fume with free download of seminar report and ppt in pdf and doc format.
Study on effect of silica fume on properties of m 40 grade of concrete rukhsana rashid1 nishant kumar2 1mtech student, 2assistant professor, department of. Numerous studies have been carried out on use of silica fume as an. American concrete institute aci 3 reported that silica fume is a byproduct of the reduction of high purity quartz with coal in electric furnaces in the production of silicon and ferrosilicon alloys. Scms in cement composites are fly ash fa and silica fume sf, that are obtained as the byproducts of the coal industry and the siliconferrosilicon industries, respectively 7,8. Effect of silica fume and mirha on thermal conductivity of. Silica fume will produce a much less permeable and high strength concrete, but it will not produce a concrete with a higher mass per unit volume. Rather than working to get that version into the a c i manual of conrete. The experimental program comprised six levels of silicafume contents as partial replacement of cement by weight at 0% control mix, 5%, 10%, 15%, 20%, and 25%, with and without superplasticizer.
Lower percentages of sio2 will yield higher exposure limits. Silica fume has been recognized as a pozzolanic admixture that is effective in greatly enhancing mechanical properties. What is silica fume red industrial products united states. Because of its chemical and physical properties, it is a very reactive pozzolan. A study on effect of silica fume on the mechanical properties of steel slag aggregate concrete devaraj p kumbar1 and v d gundakalle2 concrete is prepared by mixing various constituents like cement, aggregates, water, etc. Properties of silica fume related to its applications. Silica fume seminar report, ppt, pdf for civil engineering. Impact of micro silica fume on engineering properties of. Silica fume consists primarily of amorphous noncrystalline silicon dioxide sio2. Fict, dip m, chartered mcim, dms consultant, united kingdom. Its individual particles are extremely small, approximately 1100th the size of an average cement particle. Silica fume affects both the fresh and hardened properties of concrete. Material supplied is from the correct supplier and the bags are clearly marked and labeled in accordance with. Pdf the aim of this paper is to investigate the effects of silica fume.
Silica fume and microwave incinerated rice husk ash mirha can lower thermal conductivity of cement paste by partially replacing cement content. Silica fume consists chiefly of fine smooth particles with a surface area of approximately 20,000 m2kg 98,000 ft2lb when measured by the bet method. The measured strength parameters of the biocomposite samples that were hardened for 28 days demonstrate that the binder consisting of optimal calcined mgo and silica fume as a total replacement. The test results showed a significant change in consistency limits of samples containing silica fume. Pdf properties of rubberized concretes containing silica. Concrete is a composite material composed of granular materials. Silica fume is available from suppliers of concrete admixtures and, when specified, is. Physical properties and chemical properties of silica fume. Silica fume is an ultrafine pozzolan with spherical particles less than 1. Experimental investigation to combine chemically with cement ije in. Supported by decades of experience and handson technical expertise, hdk.
The transport properties through the silica fume concrete medium are dramatically curtailed, i. Fa, limestone fines and silica fume microsilica on the properties of concrete. This chapter looks at those properties and at how silica fume actually contributes to the improvements in fresh and hardened concrete. Two types of tire rubber, crumb rubber and tire chips, were used as fine and coarse aggregate, respectively. Properties of both fresh and hardened silica fume concrete are affected significantly compared to normal concrete. Silica fume may contain trace amounts silica fume on the properties of concrete as defined in concrete society report 74, cementitious materials.
With the proper use of silica fume not only the mechanical properties can be improved, but also the durability of concrete. Concrete containing silica fume can have very high strength and can be very durable. Physical properties of silica fume silica fume supplier. Experiments indicate that concretes become more cohesive and less prone to segregation in the presence of silica fume, moreover, performance of water demand, setting. Serving the refractory and mineral processing industries. It also included two mixes with15% silica fume added to cement in normal concrete.
It also aids the flow of powders and prevents caking. The contrast with other excellent materials illustrates the extreme fineness of silica fume. Effect of silica fume on mechanical properties of concrete. Study on effect of silica fume on properties of m40 grade.
Particle size is extremely important for both the physical and chemical contributions discussed below of silica fume in concrete. Numerous studies show that the specific properties of silica fume allow producing concretes. This makes it approximately 100 times smaller than the average cement particle. The influence of silica fume on the mechanical and thermal. Silica fume reduces bleeding and enhances the cement paste bond to the aggregates. A series of laboratory experiments have been conducted on samples with 0%, 5%, 10% and 15% of silica fume by weight of dry soil. This paper covers the physical, chemical properties of silica fume, and its reaction mechanism. Other physical properties, such as the bulk density, thermal conductivity coef. Silica fume, a byproduct of the ferrosilicon industry, is a highly pozzolanic material that is used to enhance mechanical and durability properties of concrete. It may be added directly to concrete as an individual ingredient or in a blend of portland cement and silica fume.
Refer to the silica fume association users manual for information on the appropriate set up for pumping and handling silica fume into silos. Silica fume, cstr74, properties of concrete, effects, cementitious materials, high performance concrete. Silica fume technical data sheet silica fume is a very fine pozzolanic material, composed of amorphous silica produced by electric arc furnaces as a byproduct of the production of elemental silicon or ferro silicon alloys. Silica fume sf, which is byproduct of the smelting process in the silicon and ferrosilicon industry. Influence of selfhealing, mixing method and adding silica fume on mechanical properties of recycled aggregates. Packaged silica fume must be stored in a dry area indoor. This paper discussed the properties of styrene butadiene rubber sbr latex modified concrete with silica fume as partial replacement of cement. Influence of silica fume on mechanical and physical.
Silica fume consists in individual ultrafine particles of silicon dioxide with a high specific surface and an average diameter of 150nm which gives silica fume its high pozzolanic properties. It provides useful rheological properties such as thixotropy and controlled drying as well as hindering the settling of pigments. Fresh and hardened properties of silica fume concrete is superior to conventional concrete. The effects on concrete are a result of the physical and chemical properties of silica fume. Due to its pyrogenic manufacturing process by combustion of silicon tetrachloride in an oxygen. Proper introduction of silica fume in concrete improves both the mechanical and. Silica fume sf modifies interfacial transition zone between cement paste and aggregate at the micro level. Benefits of using silica fume in concrete civil engineer. This report describes the physical and chemical properties of silica fume. A test program was carried out to develop information about the mechanical properties of rubberized concretes with and without silica fume. Silica fume, pozzolan, workability, compressive strength, flexural strength. Study on the effect of silica fume on the properties of. The best approach is to combine the use of the chart with a little common sense.
Influence of silica fume on mechanical and physical properties of recycled aggregate concrete. Thanks to its pozzolanic effect reaction with caoh2, and therefore to the strength improvement, silica fume can be used to reduce to the cement content of the mix. Odot experience with silicafume concrete dennis bunke two bridgedeckoverlay projects placed in 1984 and 1987 are the basis for ohios specifications on the use of silica fume. Since its first production in the early forties of this century, fumed silica has found widespread use in industrial applications. Silica fume is a precipitate from a gas phase what basically defines its properties.
This study is designed to explain the contradictory evidence and establish the role played by silica fume in controlling the strength of concrete and its constituent materials. Effect of silica fume as a component of alternative binder. 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. The american concrete institute aci defines silica fume as a very fine noncrystalline silica produced in electric arc furnaces as a by product of production of elemental silicon or alloys containing silicon. Figure 3 silica fume silica fume is 100x finer than cement and the. Chapter 3 describes primary uses of silica fume in concrete. Silica fume is very effective in the design and development of high strength high performance concrete. Fumed silica is a useful additive for liquid and solid systems. Procedure for handling silica fume scancem materials. Twa value 20 millions of particles per cubic foot of air twa value 0. Pdf study on the effect of silica fume on the properties of brick. One of the most beneficial uses for silica fume is in concrete.
The latex modified concrete using sbr latex were prepared with various polymerbinder ratio and 8% silica fume contents, and tested for compressive strength, flexure strength and elastic modulus. Pdf effects of silica fume and fly ash on the properties of high. Pozzolanic and cementitious a combination of both properties. It therefore effectively fills in empty pores in the cement and helps produce a stronger, more compact material. In the united states, silica fume is used predominantly to produce concrete with greater resistance to chloride. Its color ranges from white to dark grey and is available in. High limits of specification need high quality soil and this not all time available in the local area of highway project.
1384 639 341 1261 1472 325 78 1516 1255 776 454 433 1272 626 1061 1541 1183 1539 595 7 789 1483 794 1011 832 442 498 1146 537 816 431 989 1209 1404 1386 807