Salt-scaling resistance of highly durable RC slabs utilizing GGBS concrete with expansive additive

Abstract

In recent years, the utilization expansive additive for ground granulated blast furnace slag (GGBS) concrete has been confirmed to be indispensable to reduce the early-age thermal tensile stress, which results in successful crack mitigation in several highly durable reinforced concrete (RC) slabs in Japan. However, various investigations have cited that the application of large amounts of expansive additive might reduce the salt-scaling resistance of durable RC slabs. This study experimentally investigates the salt-scaling resistance on the top surface of highly durable RC deck slab specimens by utilizing GGBS concrete with applicable dosages of expansive additive. Test results revealed that the proposed salt-scaling method modified based on ASTM C672 with a 6 h cycle and with more severe scaling temperatures at a minimum and maximum of ± 35 °C can reasonably reduce the experimental duration and effort for practical purposes. Moreover, although the salt-scaling resistance of the highly durable RC slab specimens decreased as the dosage of the expansive additive increased, acceptable salt-scaling resistance was obtained in the specimens with 20 and 25 kg/m3 expansive additive dosages.