What To Know About Silica Fumes For Concrete?
While producing silicon or a ferrosilicon alloy, silica fumes are obtained as a by-product. These fumes are extensively used as an additive to concrete, in order to increase the strength of the concrete. It is largely due to the physical and chemical attributes the silica fumes are considered extremely reactive pozzolan.
Concrete, containing silica fumes, have great durability and strength. These fumes are available with the concrete contractors. When specified, they add the fumes.Handling the silica-fume concrete require careful attention and caution from the concrete contractor. Silicon is made in electric furnaces using coal, woodchips and quartz.
Amorphous silicon dioxide is the main constituent of silica fume. The individual particles are as small as 1/100th part of an average particle of cement. The fine particles, considerably high SiO2 content and the large surface area are primarily responsible for silica fume to be a very reactive pozzolan.
Thanks to the huge surface area that silica fume particles have, they affect the movement of water inside theconcrete; segregation and bleeding are almost totally eliminated. The transporting property of concrete that is induced with silica fume is adversely affected. Liquid and even electricity experience such diminished migrating ability. This results in high electrical resistivity.
Precautions to be taken while using Silica Fumes in Concrete
Although silica fumes are beneficial for concrete, the silica fumes for concrete requires special attention. The transportation, placing, finishing and curing of silica fumes shall be carried on abiding the proper and prescribed concreting techniques. The required level of practice has been prescribed by the American Concrete Institute.
Flatwork that contains silica fume concrete generally requires less finishing effort than conventional concrete.The finishing process requires the silica-fume concrete to be placed, consolidated, and textured. Curing of concrete is a must if one desires to get the most out of silica fumes.