Ternary Cement Composites with Metakaolin Sand and Calcined Clayey Diatomite

The advancement of cement composites with different pozzolana types represents needful domain in civil engineering. Utility properties of such composites are closely approaching the level of standard quality. The raw materials – kaolin sand thermally transformed at 650 °C/hour and clayey diatomite calcined at 900 °C/hour were used in the experiment. Cement ternary composites containing 5 and 10 wt.% of metakaolinite as well as 5 and 10 wt.% of calcined clayey diatomite (in varied proportions) with water to solid ratio of 0.5 were manufactured for this study. The physical-mechanical and physical-chemical behaviour of relevant ternary systems after 28-days water curing are presented in this paper. Thermal analysis disclosed calciumsilicate hydrate (CSH) and calciumaluminate hydrate (CAH) formation, portlandite dehydroxylation and calcite decarbonation. Portlandite content reduction was found as a result of respective pozzolanic reaction unlike reference composite without pozzolana. This statement was confirmed by X-ray diffraction analysis. The favourable standard mechanical properties (compressive strength) in this study of composites were documented as well. Results exhibit the effective pozzolanic reaction susceptible the attainment of valuable utility properties of cement composites.