Effect Of Nano Metakaolin On The Physico-Chemical And Mechanical Properties Of Various Blended Cement Pastes

Abstract

The physico-chemical and mechanical characteristics of various cement pastes are studied in presence of nanometakaolin (2, 4, 6 and 8%) and in absence and presence of different percentages of some industrial wastes such as ground clay bricks, ground granulated blast furnace slag, cement kiln dust and silica fume. The characteristics of these blended pastes are investigated at different hydration times (1-180 days) via determination of the compressive strength, total porosity and chemically combined water content. In addition, the phase composition of the formed hydrates is investigated through X-ray diffraction analysis. The microstructural changes are studied using scanning electron microscopy. The IR spectra and DTA of some cement pastes are also recorded. The results show that the highest compressive strength is obtained for the cement mix blended with 8% NMK in absence of any other additives. In presence of the above mentioned additives, the optimum compressive strength is attained for mixes B, which contain 70% OPC, 20% GCB or slag, 6% CKD or SF, beside 4% NMK. The data obtained for other parameter agree well with the above findings.