Effect of Nano-TiO2 at macro and micro level of concrete by partial substitution of cement

Abstract

At macro level the strength of the concrete will decline due to several reasons like high water-cement ratio, improper compaction and improper curing. At micro level concrete strength will reduce due to poor pore structure. Since the cement acts a binding agent upon reacting with water, the fineness of the cement influences the strength. Higher water cement ratio leads to higher porosity. Fine particles of very high specific surface area may affect the pores of concrete leading to strength enhancement rather than decline. In this study is aimed to study the effects of partial substitution of nano-TiO2 for cement into concrete, on mechanical strength and microstructure. Fresh and hard macro level properties are investigated for M40 and M60 with cement replacement 0% to 2% by nano-TiO2. SEM images were examined for studying dispersion of particles and XRD for products of hydration at micro level. It is found that at 1% of nano-TiO2 strength for M40 and M60 were higher with other percentages replacements.