Interpretation of Preferable Curing Conditions in the Realization of Durable Self-Compacting Geopolymer Concrete

The construction industry faces significant challenges related to the durability of concrete structures, especially in harsh environmental conditions. Issues such as high water permeability, abrasion, chemical degradation, and carbonation affect the longevity of concrete structures, necessitating periodic concrete maintenance. Self-compacting geopolymer concrete (SCGC) is gaining prominence due to its ease of placement, waste management benefits, and enhanced strength compared with that of conventional concrete. However, although curing plays a pivotal role in the geopolymerization process, comprehensive studies of its influence remain limited. This research investigated the influence of curing conditions on the durability characteristics of ground granulated blast furnace slag (GGBFS)-based and GGBFS–fly ash (FLA)-based SCGC mixes. Long-term durability studies performed on 28-day-cured SCGC samples to determine the influence of diverse curing conditions included physical characteristics analysis (abrasion test), water transportation characteristics investigation (sorptivity test), chemical characteristics evaluation (acid and sulfate resistance tests), and corrosion characteristics interpretation (carbonation and chloride ion penetration tests). The curing conditions studied were ambient-temperature curing, oven heat curing, external-exposure summer curing, and external-exposure winter curing. A scanning electron microscopy (SEM) test was conducted to determine the microstructural changes that occur in SCGC mixes under assorted curing conditions. The results demonstrate that curing conditions significantly influence the durability characteristics of SCGC, and curing under elevated temperatures led to improved performance due to enhanced geopolymerization and a denser microstructure. GGBFS-based mixes consistently manifested superior resistance under ambient-temperature curing, whereas GGBFS-FLA mixes had better performance under high curing temperatures. The findings indicate that optimal curing methods and binder composition are crucial for enhancing the durability characteristics of SCGC in aggressive environments. This research provides essential insights for optimizing mix designs in concrete construction to improve long-term performance and minimize maintenance costs.