Effects of elevated temperatures on the thermal behavior and mechanical performance of fly ash geopolymer paste, mortar and lightweight concrete

摘要: Abstract This paper reports a comparative study of the influence elevated temperature on geopolymer paste, mortars and lightweight aggregate concrete (LWAGC) systems made by using fly ash (FA) as only source material. The mechanical, thermo-physical macro/micro-structural properties geopolymers before after exposure to temperatures 400, 600 800 °C have been investigated. sequential changes in geopolymeric gel structure upon their reflections thermal behavior also explored. physical unexposed show that LWAGC possesses lower density water absorption than paste mortar. mechanical strength materials prior firing shows mortar significantly high compared LWAGC, due (LWA) low porous microstructure. It is found relatively activator content used activate raw material, FA, results excellent microstructural for temperatures. While, it participating deterioration exposed especially at producing unreacted silicate species. Introducing LWAs considerably enhances attributed conductivity characteristics which inhibited heat diffusion through structure. reported performance LWAGCs would increase suggested application this novel environmentally-friendly