Usman Kankia, M. and Baloo, L. and Danlami, N. and Zawawi, N.A. and Bello, A. and Muhammad, S.I. (2023) Microstructural Analysis and Compressive Strength of Fly Ash and Petroleum Sludge Ash Geopolymer Mortar under High Temperatures. Sustainability (Switzerland), 15 (12).