Micro Structure Properties of Parent Concrete with Nano Silica and Polypropylene Fibre in Recycled Aggregate

This paper involves the study made to investigare the effects of colloidal nano silica and their properties on concrete with a constant replacement of recycled aggregates at a level of 100%. Polypropylene fiber of 2% is added in all mixes to enhance tensile properties of concrete. In many cities there is a surge in construction and demolition wastes constitute the major portion of solid waste production in the world. The reuse of such wastes as a new construction material were used to reduce the huge amount of natural resources. Here, ordinary Portland cement is replaced by weight fraction of nano silica at replacement levels of 0%, 0.5%, 1%, 1.5%, and 2%. The colloidal nano silica act as a filler material which increase some of the mix properties, it also act as accelator to enhance pozzolonic action. The further presence of nano silica enhance the strength and properties of concrete up to 1.5% of replacement criteria, such as mechanical strength tests were conducted in concrete mixes. it has been concluded from scanning electron microscope (SEM) analysis that the denser matrix is formed at 1.5% of replacement of nano silica.