Physico-mechanical characteristics of blended white cement pastes containing thermally activated ultrafine nano clays

NMK were incorporated at a rate of 2%, 4%, 6%, 8%, 10%, 12% and 14% by weight of cement. Hardened blended cement pastes were prepared by using water/cement ratio (W/C) of 0.3 by weight and hydrated for various curing ages 3, 7 and 28 days. In order to study the mechanical and physical characteristics of the hardened cement pastes incorporating NMK, different techniques were used such as compressive and flexural strength testing, differential scanning calorimeter (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The experimental results of this study showed that thermal activation of the nano kaolin leads to transformation of the kaolinite to amorphous phase accompanied with the reduction in grain size. The partial replacement of cement by NMK is helpful in enhancing the compressive and flexural strength of cement products. There was an enhancement of compressive strength by about 50% and flexural strength by 36% at 10% nanoclay. The microstructure of the cement blended with NMK was denser, compact and more uniform than that of the conventional cement.