A preliminary study of blended pastes of cement and quartz powder under the effect of elevated temperature

A preliminary study of the possibility of using quartz powder (QP) as mineral admixture substituting Portland cement (PC) to resist elevated temperature and thermal shock was carried out. 0, 5, 10, 15 and 20 wt.% QP was replaced PC. The various hardened pastes were exposed to elevated temperatures of 200, 400, 600, 800 and 1000 °C for 2 h. The residual strengths of these specimens were determined after gradually cooling and compared with their original before exposing to elevated temperature. Further, water quench test was applied to determine the thermal shock resistance of various hardened cement pastes. The results are discussed using material characterization experiments namely, X-ray diffraction (XRD) analysis, derivative thermogravimetric (DTG) analysis and scanning electron microscopy (SEM). The experimental results show that the QP enhances both elevated temperature and thermal shock resistance of the cement pastes.

0, 5, 10, 15 and 20 wt.% quartz powder was replaced Portland cement. The various hardened pastes were exposed to various elevated temperatures for 2 h. The residual strengths were determined and compared with their original. Water quench test was applied to determine thermal shock resistance of various hardened cement pastes.Figure optionsDownload as PowerPoint slideHighlights▸ QP blended cement pastes are more resistant to elevated temperatures than neat PC pastes. ▸ The resistance to thermal shock of the cement pastes is increased when PC is replaced with QP. ▸ As QP increased in the hardened cement pastes (up to 20%) as the thermal shock resistance increased. ▸ The improved fire and thermal shock resistances can be attributed to lower Ca(OH)2 cussed by QP. ▸ Also the improvements can be attributed to formation dense structure caused by QP.