Effect of elevated temperatures on compressive strength and microstructure of cement paste containing palm oil clinker powder

Residual compressive strength of cement after exposure to elevated temperatures is important when introduces a new supplementary cementitious material for cement based applications. Palm oil clinker (POC) is a residue produced upon burning of palm oil shells and fibres in a boiler of palm oil mill. The aim of this work is to evaluate the high temperature effect on compressive strength and microstructure change of palm oil clinker powder (POCP) containing cement paste. The palm oil clinker powder containing cement (POCPC) was prepared for 30% replacement of ordinary Portland cement (OPC). Elevated temperatures at 300 °C, 600 °C, and 800 °C have been maintained for 3 h for both OPC and POCPC paste. The compressive strengths of OPC and POCPC were measured at the curing age of 7, 28, 56 and 90 days. The mineralogy, IR spectroscopy, thermal analysis and microstructure were investigated using XRD, FTIR, TGA and FESEM, respectively. The compressive strength of POCPC is significantly higher than that of OPC sample when thermally activated at 600 °C and 800 °C for 3 h. The XRD, FTIR, TGA and FESEM results reveal that more hydration products (C-S-H) sustain in POCPC compare with OPC after exposure to elevated temperature that is the causes behind higher compressive strength in POCPC.