Nanotechnology
in concrete

A new
supplementary cementing material called nano silica (NS) has emerged on the
market and has attracted many researchers across different fields, mainly owing
to its high silicon dioxide (SiO2) content and its nano size particles.  NS reacts with the calcium hydroxide of cement
hydration and forms calcium-silicate-hydrate gel which fills the interconnected
pores and alters their distribution. This in turn reduces the porosity of the
concrete matrix and increases its permeability resistance. Additionally, it
behaves as a nucleus that tightly bonds with cement hydrate, forming a stable
gel structure which shows closer packing. With the current research findings
indicating significant early strength gain in conventional concrete, there are
strong grounds to believe that NS could successfully be used and incorporated
in recycled aggregate concrete to compensate the loss in mechanical strength
and to improve the durability properties. The reference of this study has been
taken from Curtin University.