Durability of Repair Metakaolin Geopolymeric Cement under Different Factors

Abstract

Nowadays, energy saving, and green sustainability are influencing the development of all industries, including the construction industry. In recent years, geopolymeric cement and concrete have become hot topic materials as a replacement for traditional OPC; this work carried out orthogonal experiments to identify four potential factors affecting the basic properties of the metakaolin-geopolymeric cement specimens. The results showed that the metakaolin and activator contents were the two primary influencing factors. Given the importance of studying the durability of building restoration materials in harsh environments, this experiment focused on testing the bond strength, permeability resistance, sulphate corrosion resistance, and freeze-thaw resistance of metakaolin geopolymer pastes with different proportions of metakaolin dopant and alkali activator content. The findings are that durability of the formed specimens significantly improved when suitable metakaolin and activator contents were incorporated, and bond strength was also improved. Moreover, the microscopic tests, including SEM and FT-IR experiments, were used to better reflect the changing durability of pattern. The experiments showed that the best durability of the metakaolin geopolymeric cement was achieved when the ratio of metakaolin to cement was 1.5 and the ratio of activator to cementitious material was 0.3. It can be concluded that the appropriate content of metakaolin and activator can give the geopolymer excellent performance under harsh conditions, which will contribute to the wide application of geopolymer.