The Effect of Ordinary Portland Cement Substitution on the Thermal Stability of Geopolymer Concrete

Hongen Zhang; Lang Li; Tao Long; Prabir Sarker; Xiaoshuang Shi; Gaochuang Cai; Qingyuan Wang

doi:10.3390/ma12162501

The Effect of Ordinary Portland Cement Substitution on the Thermal Stability of Geopolymer Concrete

Materials (Basel). 2019 Aug 7;12(16):2501. doi: 10.3390/ma12162501.

Authors

Hongen Zhang^{1

2

3}, Lang Li^{1

3}, Tao Long^{1

3}, Prabir Sarker², Xiaoshuang Shi^{4

5}, Gaochuang Cai⁶, Qingyuan Wang^{7

8

9}

Affiliations

¹ Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China.
² Department of Civil Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
³ Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, Sichuan University, Chengdu 610207, China.
⁴ Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China. shixs@scu.edu.cn.
⁵ Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, Sichuan University, Chengdu 610207, China. shixs@scu.edu.cn.
⁶ Univ Lyon, Ecole Nationale d'Ingénieurs de Saint-Etienne (ENISE), Laboratoire de Tribologie et de Dynamique des Systèmes (LTDS), UMR 5513, 58 Rue Jean Parot, 42023 Saint-Etienne CEDEX 2, France.
⁷ Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China. wangqy@scu.edu.cn.
⁸ Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, Sichuan University, Chengdu 610207, China. wangqy@scu.edu.cn.
⁹ School of Mechanical Engineering, Chengdu University, Chengdu 610106, China. wangqy@scu.edu.cn.

Abstract

The influence of using cement on the residual properties of fly ash geopolymer concrete (FAGC) after exposure to high temperature of up to 800 °C was studied in terms of mass loss, residual compressive strength and microstructure. The mass loss was found to increase with the increase of exposure temperature, which is attributed to vaporization of water and dehydroxylation of sodium aluminosilicate hydrate (N-A-S-H) gels. The dehydroxylation of calcium silicate hydrate (C-S-H) gels and the disintegration of portlandite were responsible for higher mass loss ratio of FAGCs containing cement. The results showed that cement could increase compressive strength of FAGCs up to 200 °C, after which a significant reduction in residual strength was observed. It was found that FAGCs without cement yielded higher residual strength than the original strength after heating up to 600 °C. The observed increase of compressive strength up to 200 °C was attributed to the secondary geopolymerization which was evidenced in the scanning electronic microscopy (SEM) images.

Keywords: elevated temperatures; geopolymer concrete; mass loss ratio; residual compressive strength; secondary geopolymerization.

Abstract

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