Effect of silica fume on engineering properties of black. Request pdf effect of silica fume on mechanical properties of highstrength concrete this paper presents the results of experimental work on short and longterm mechanical properties of high. 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 effects of silica fume sf on compressive strength of concrete have been analyzed. Silica fume has been recognized as a pozzolanic admixture that is effective in greatly enhancing mechanical properties. Examples include silica fume meeting the requirements of astm c 1240. This makes it approximately 100 times smaller than the average cement particle. The objective of the study is to evaluate the effect of using silica fume on the properties of fresh and hardened concrete made with crushed bricks through experimental investigation. Figure 4 approximately 100,000 silica fume silica fume particles fill the space between cement grains.
These materials can exhibit the following properties. Silica fume typically 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. 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. Silica fumes benefits are already evident in the fresh concrete state before it. Parallel studies of strength, heat of hydration, hydration and internal relative humidity were carried out. This paper focuses on the effects of silica fume on all the main properties of concrete in the fresh and hardened state as defined in the publication. Irrespective of the delivery form of silica fume i. Silica fume seminar report, ppt, pdf for civil engineering.
Fresh and hardened properties of silica fume concrete is superior to conventional concrete. It deals with permeability, corrosion, carbonation and resistance against freezingthawing, sulfate, alkaliaggregate. What is fly ash, slag, and silica fume and why do we use. The effect of silica fume on the principal properties of concrete. This video introduces fly ash, slag and silica fume and discusses their properties. Silica fume, cstr74, properties of concrete, effects, cementitious materials, high performance concrete. Silica fume o silica fume is a product resulting from reduction of high purity quartz with coal is an electric arc furnace in the production of silicon or ferrosilicon alloy.
This term refers to materials that are used in concrete in addition to portland cement. Effect of silica fume on mechanical properties of concrete. Bureau of reclamation engineering and research center denver, co 80225 0 11. The global chemicals industry faces economic and environmental pressures, thats why many of our suppliers like silica fume factory are always innovating to provide more. Explore silica fume with free download of seminar report and ppt in pdf and doc format. Their properties the lenghtening of a mortar layer, tensile strength and strength of adhesion to concrete may be regulated while changing the quantities of cement and plasticisers. Astm c1240 20 standard specification for silica fume. This problem is particularly common in laboratories having small, and often less efficient, concrete mixers. The compressive strength results of concrete mixed over different waterbinder ratios as well as different replacing percentages of sf were analyzed. The improvement of geotechnical properties of weak soils is of interest through the resources shortage. The transport properties through the silica fume concrete medium are dramatically curtailed, i. Properties of both fresh and hardened silica fume concrete are affected significantly compared to normal concrete. This abstract is a brief summary of the referenced standard. It is observed that the addition of silica fume decreases the development of cracks on the surface of compacted clay samples reducing the cracks width by 75%.
The results of the experiments showed that when the polymerbinder materials ratio increases, the compressive strength of concrete decreases. Silica fume was added to the kaolinite clay to enhance the. Experiments indicate that concretes become more cohesive and less prone to segregation in the presence of silica fume, moreover, performance of water demand, setting of. Properties of silica fume related to its applications.
As with conventional concretes, silica fume can generally be used with chemical admixtures, and it is usually used with a super plasticiser. Silica fume is usually categorized as a supplementary cementitious material. Silica fume was kindly provided by metalleghe spa, brescia, italy, as an industrial byproduct derived from ferrosilicon and silicon metal alloy processing. Pozzolanic will not gain strength when mixed with water. The effect of using silica fume on the workability of concrete due. These properties indicated silica fume concrete would have a number of advantages when used for the repair of concrete structures. For instance, it has higher compressive and flexural strength. Guide to using silica fume in precastprestressed concrete. Effect of silica fume on mechanical properties of high. Silica fume influences the thickness of transition phase in mortars and the degree of the orientation of the ch crystals. The chemical composition of silica fume is reported in rodella et al. Silica fume is an ultrafine pozzolan with spherical particles less than 1. This study investigated the properties of hardened pastes made with calcium sulfoaluminate expansive agent csa, red mud, and silica fume. 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.
Therefore, this study focused on the effect of silica fume as industrial waste products and nanosilica on geotechnical characteristics and microstructural properties of kaolinite clay as a soft soil with poor strength properties. However, because of several drawbacks associated with properties of cement and manufactured building materials usinf opc as well as the cost factor attempts. Pdf effects of metakaolin and silica fume on properties. Figure 2 silica fume reacts with the weak leachable caoh. China silica fume, silica fume manufacturers, suppliers. Comparative study of the characteristics of nano silica.
Effects of silica fume on concrete compressive strength. Pdf study on the effect of silica fume on the properties. A new porous hybrid material derived from silica fume and. Fa, limestone fines and silica fume microsilica on the properties of concrete. Silica fume, pozzolan, workability, compressive strength, flexural strength. Properties, advantages, and applications silica fume concrete is composed of cement, silica fume, fine aggregate, coarse aggregate, and water. Silica fume shall be stored in such a manner as to permit easy access for the proper inspection and identification of each shipment. The diameter of the silica fume particle ranges from 0. The silica fume pellets can be ground with portland cement clinker to form a blended cement. 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. Pdf effect of silica fume in concrete researchgate.
Pdf characteristics of silica fume concrete researchgate. Silica fume sf modifies interfacial transition zone between cement paste and aggregate at the micro level. Silica fume can also be pelletized, whereby the silica fume is mixed with water and some cement. To prepare samples, food grade calcium bicarbonate was bought in a local store. 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 concrete is composed of cement, silica fume, fine aggregate, coarse aggregate, and water. This paper examines the influence of addition of the first three of the above forms of silica fume on the properties of plastic and. The physical properties of high strength silica fume concretes and their sensitivity to curing procedures were evaluated and compared with. Effects of metakaolin and silica fume on properties of concrete article pdf available in aci materials journal 994. It is informational only and not an official part of the standard. This report describes the physical and chemical properties of silica fume. The permeability of soil increased with increase in silica fume content. 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. Introduction silica fume can be used either as a densified or undensified powder, a slurry, as a combination.