Development of high performance concrete using industrial waste materials and nano-silica

Abstract

There is a concerted effort worldwide to use environment-friendly binders in the establishment of civil infrastructure. The use of such materials, as a partial or total replacement of Portland cement, leads to technical, economic and environmental benefits. The reported study was conducted to develop high performance concrete (HPC) utilizing two industrial waste materials (IWMs), namely cement kiln dust (CKD) and electric arc furnace dust (EAFD), in conjunction with nano-silica (NS). The mechanical properties, morphology and durability characteristics of the developed HPC were evaluated. The strength of concrete decreased with increasing quantity of both CKD and EAFD that were used as a partial replacement of cement. However, an increase in strength was noted due to the incorporation of NS. The chloride permeability significantly decreased due to the incorporation of 5% NS in CKD and EAFD cement concretes. A dense and uniform microstructure, with a compact interfacial transition zone, was noted in concrete specimens incorporating Portland cement, IWMs and NS. The incorporation of IWMs along with NS results in the following benefits: environmental (decreased greenhouse gas emission and solution of the disposal problem associated with the IWMs), economic (decreased overall cost of concrete) and technical (enhanced service life of structures).