effect of silica fumes on concrete properties andits,effect of silica fumes on concrete properties andits advantages swetanshu dubey1, gautam bhadoria2 1m. tech student, department of civil engineering, mits, gwalior, india 2professor, department of civil engineering, mits, gwalior, india abstract: cement is the most important building material used in the construction industry..the effect of silica fume on the properties of concrete …,the new concrete society publication, cementitious materials, cstr74, covers the effects of cementitious materials blast furnace slag (ggbs), fly ash (fa), limestone fines and silica fume (microsilica) on the properties of concrete. 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..
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influence of silica fume on the properties of self development of a suitable mix for scc such as the effect of water to cement ratio, limestone and silica fume that would satisfy the requirements of the j. m., bartos, 'measurement of key properties of fresh self-compacting concrete…
in addition silica also helps to hydrate the cement and form c-s-h thus helping to increase the concrete’s strength. however, there are impurities in silica fume i.e. there is mixture of larger size silica particles which are formed during grinding. it has been reported that such larger size silica are reactive and aggravate asr.
fresh concrete containing silica fume is more cohesive and less prone to segregation than concrete without silica fume. concrete containing silica fume shows substantial reduced bleeding. additionally, silica fume reduces bleeding by physically blocking the pores in the fresh con-crete. use of silica fume does not signi cantly change the unit
adding silica fume improved the workability, already 2.5 vol% lead to workable mortar mixed with w/b ratios of 0.3. the viscosity for the final mixture was lower for those in which potassium hydroxide was used compared to those where sodium hydroxide was used. therefore, following tests were conducted with potassium hydroxide.
this effect is caused primarily by thehigh surface area of the silica fume to be wetted; there is very little free water left in the mixture for bleeding.additionally, the silica fume reduces bleeding by physically blocking the pores in the fresh concrete. plastic shrinkage cracks generally occur when the water evaporation rate from the
as a concrete admixture, silica fume has a certain influence on the performance of concrete. effect of silica fume in concrete workability the incorporation of silica fume in concrete can improve the “stability” of concrete, which can reduce the segregation and bleeding of concrete.
silica fume’s benefits are already evident in the fresh concrete state before it begins to harden. its small particle size which is 100 times finer than ordinary portland cement complements the finess modulus of concrete and provides a ball-bearing effect, which improves thixotropic behavior, in effect modifying concrete viscosity.
various mixtures of eps foamed concrete are produced by partial replacing normal aggregates by 0%, 15%, 25%, 35% and 50% of eps foam beads by volume. in eps foamed concrete, the ordinary portland cement (opc) was replaced by silica fume (sf) with different ratios 0%, 5%, 10 and 15% by weight. sixteen mixtures are prepared to investigate the fresh,
the formulation is based on ground granulated blast furnace slag and as an activator a combination of potassium water-glass and potassium hydroxide was used. furthermore, silica fume and metakaolin as inorganic fines were used to increase the packing density of the mixture. quartz sand (0–2 mm) and quartz powder were added as aggregates.
the effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (scgc) was investigated in this paper. the work focused on the concrete mixes with a fixed water-to-geopolymer solid (w/gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m 3 .
this paper investigates the effect of silica fume (sf), added in varying percentages (0, 3, 5, 7.5, 10, 12.5%), on concrete strength. superplasticiser - (viscocrete tempo 12) - was added to the concrete mixtures as well. compressive strength, shear strength and tensile strength tests were conducted, and the results were discussed.
compressive strength silica fume is generally known to improve the mechani- cal properties of concrete . the inclusion of silica fume in concrete causes significant changes in the structure of the matrix by both a physical action and a pozzolanic reac- tion.
applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%. the effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (scgc) was investigated in this paper.
however, the concrete with silica fume shows larger stress at any level of strain. it means that use of silica fume has a positive impact on the stiffness of concrete. hence, the modulus of elasticity of concrete at 7 days has found to increase at 7 days. similar trend can also be
the presence of silica fume in fresh concrete results in significantly reduced bleeding and greater cohesiveness. this is a physical effect, the result of incorporating extremely fine particles into the mixture. the higher the silica fume content, the more pronounced the effect.
form economical point of view. silica fume is a material which may be a reason of air pollution this is a byproduct of some industries use of microsilica with concrete decrease the air pollution. silica fume also decrease the voids in concrete. addition of silica fume reduces capillary 7. absorption and
concrete increases with the addition of silica fume. it has also been found from the investigation that the enhancement effect using silica fume increases with the age of concrete. keywords-silica fume; brick aggregate; compressive strength; tensile strength; flexural
silica fume concrete is composed of cement, silica fume, fine aggregate, coarse aggregate, and water. fresh and hardened properties of silica fume concrete is superior to conventional concrete. for instance, it has higher compressive and flexural strength.
furthermore, the effect of silica fume decreases with increasing cement content and decreasing water-cementitious ratios. at a cement content of 500 kg/m3 (840 lb/yd3) and a water-cementitious ratio of 0.28, it was not possible to increase the strength of concrete using silica fume to replace cement.
it was observed that the addition of 5 % silica fume to concrete with 50 % recycled aggregate was subsequently accompanied by 4.2 % and 5.5 % increase in the fresh and hardened pervious concrete density, respectively, while a 17.5 %, 11.7 % and 17.2 % decrease in the hardened concrete voids content, concrete permeability and concrete degradation, respectively.
the effects of silica fume (sf) on compressive strength of concrete have been analyzed. the compressive strength results of concrete mixed over different water–binder ratios as well as different replacing percentages of sf were analyzed. the results of the experiments showed that when the polymer/binder materials ratio increases, the compressive strength of concrete decreases.
1. addition of silica fume to the concrete containing steel slag as coarse aggregate reduces the strength of concrete at any age. 2. this is due to the formation of voids during mixing and compacting the concrete mix in vibration table because silica fume make the mixture sticky or more cohesive which do not allow the entrapped air to escape.
a superplastisizer (1% by weight of cement) was added to this slurry which increased infiltration capacity of the slurry. to study the effect of replacement of cement by silica fume on sifcon, slurry was prepared by replacing cement by silica fume at varying percentages like 5%, 10%, 15%, 20%, 25% and 30% by weight of cement.
silica fume concrete silica fume is an artificial pozzolona having high pozzolonic activity. it is a by- product from an electric arc furnace used in manufacture of silicon metal or silicon alloy. it has high silica content of more than 80%. it is an excellent for use as a portland cement