Abstract:
Nowadays, supplementary cementitious materials (SCMs) are used in concrete because it
reduces CO2 emission during. The husks, which are production of cement, reduces cement
contents, improve workability, increase strength and enhance durability. Pozzolanic reaction
takes place when siliceous or aluminous material comes in contact with calcium hydroxide in
the presence of moisture to form compounds possessing cementitious properties
approximately 50 percent cellulose, 30 percent lignin and 20 percent silica, are incinerated
by controlled combustion leaving behind an ash that predominantly consists of amorphous
silica. Rice husk ash is highly pozzolanic due to its extremely high surface area (50,000 to
100,000 m2/kg). The colloidal nano silica (CNS) which is nano material and behaved not only
as a filler to improve cement micro-structure (porosity decrease), but also as a promoter of
pozzolanic reaction used in cement for accelerating pozzolanic action due to which the
cement sets faster than conventional mix. In the present study, the mineral admixture, rice
husk ash (RHA) was used as 5, 10, 15% replacement for OPC in M60 grade of concrete. The
10% RHA was taken as optimum dose on the basis of workability and compressive strength.
To this 10% RHA concrete, effect of 1, 2, 4, and 6% CNS addition were experimentally
studied with various properties like workability, compressive strength and split tensile
strength.
