Investigation on the Effect of Seawater Condition, Sulphate Attack, Acid Attack, Freeze-Thaw Condition, and Wetting-Drying on the Geopolymer Concrete

This study investigated the durability analysis of geopolymer concrete and conventional concrete specimens, which includes the seawater condition (5% NaCl), sulphate attack (5% sodium sulphate or 5% magnesium sulphate), acid attack (5% sulphuric acid), freezing-thawing, and wetting-drying tests as per the ASTM. In the initial, to make the GPC and conventional concrete mix-design specimens for reference to durability tests. The mass loss, compressive strength, and UPV tests were conducted on both concrete specimens during every durability test after 6 weeks, 12 weeks, 18 weeks, and 24 weeks in seawater condition, sulphate attack, and acid attack, whereas for freeze-thaw and wetting-drying tests were conducted after 30 cycles, 45 cycles, 60 cycles, 75 cycles, and 90 cycles. After immersion in the seawater solution, sodium sulphate solution, and magnesium sulphate for 12 weeks, both concrete specimens were strengthened. However, both concrete specimens degraded continuously after 12 weeks. Thus, the GPC specimens show higher resistance than conventional concrete specimens against for same. The GPC and conventional concrete specimens show that mass losses are 8.1% and 14.2% after 24 weeks of exposure time, respectively, whereas the GPC and conventional concrete specimens retained 56% and 32% compressive strength of original, respectively, after 24 weeks exposure to same. The mass loss of GPC specimens is 7.2% after 90 cycles of freeze-thaw, whereas the conventional concrete specimens show only 2.1% mass loss. The conventional concrete depicts higher strengthening than GPC specimens in the wetting-drying condition. The wetting-drying cycles strengthened the compressive strength of the GPC and conventional concrete specimens, with the GPC and conventional concrete specimens retain 107% and 109% compressive strength of original after 90 wetting-drying cycles, respectively. Among all durability tests, analysis shows that the acid attack is more vulnerable than the other durability test conditions for both GPC and conventional concrete. The GPC specimens are more resistant to durability conditions than OPC concrete specimens.