Temperature for geopolymerization of fly ash. Mechanical behaviour

Abstract

Alkali activation of fly ash (FA) is a chemical process which allows the transformation of the amorphous structure which makes up most of its particles, in compact cementitious skeletons geopolymers are called solid materials usually consist of a alkali hydroxide and solid precursor high content in silicon (Si) and aluminium. This paper presents the effect of temperature and the curing time in the alkali activation in FA pastes with 8M NaOH, geopolymers curing was carried out at room temperature, 60 °C and 80 °C at aged 7 14 and 21 days. Compression tests were conducted to obtain the strength of the geopolymer and analysis by X-ray diffraction to determine the new phases present resulting in higher compression resistance with higher temperature and curing time, a change was detected in the diffractogram because new phases present in the alkaline activation product.