TY - JOUR IS - 12 N2 - The development of sustainable building materials and construction to decrease environmental pollution in both production and operational stages of the materialsâ?? life cycle is appealing to great interest in the construction industries worldwide. This study evaluated the negative effect of temperature up to 1000 °C on the compressive strength and microstructure of fly ash and petroleum sludge ash (PSA) geopolymer mortar. A sodium silicate and sodium hydroxide mixture is used as an activator. The synthesized mortar was investigated using X-ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Mercury Intrusion Porosimetry (MIP), and Field Emission Scanning Electron Microscopy (FESEM). As the temperature increased, the compressive strength of the geopolymer mortar decreased. The strength degradation is due to the damage to microstructure because of the temperature-induced dehydroxylation, dehydration thermal incompatibility between geopolymer aggregate and paste of geopolymer mortar at high temperatures. With an increase in temperature, the cumulative pore volume increased. The FESEM image showed the decomposition of the geopolymer matrix started at a temperature of 600 °C. Incorporating PSA in geopolymer mortar could result in an eco-friendly and sustainable environment that may reduce the problems associated with sludge disposal. © 2023 by the authors. N1 - cited By 1 KW - compressive strength; construction material; decomposition; degradation; dehydration; fly ash; high temperature; microstructure; mortar; sludge; X-ray diffraction TI - Microstructural Analysis and Compressive Strength of Fly Ash and Petroleum Sludge Ash Geopolymer Mortar under High Temperatures ID - scholars18488 AV - none UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85164142025&doi=10.3390%2fsu15129846&partnerID=40&md5=e06cfca1fe78c53872343d76fe424621 A1 - Usman Kankia, M. A1 - Baloo, L. A1 - Danlami, N. A1 - Zawawi, N.A. A1 - Bello, A. A1 - Muhammad, S.I. JF - Sustainability (Switzerland) VL - 15 Y1 - 2023/// ER -