Effects of CaO addition on lightweight aggregates produced from water reservoir sediment

Lightweight aggregates were produced from water reservoir sediment with various amounts of CaO at calcining temperatures of 1170 °C–1230 °C. It was found that C–S–H gel did not form with CaO addition. The bulk density and compressive strength of the lightweight aggregates meet the regulations for lightweight structural concrete. The properties of samples with 1% CaO by weight calcined at 1200 °C match those of a commercial product. Water adsorption and compressive strength decreased with increasing CaO addition since more of the glassy phase formed, which sealed pores and led to few connections between pores.