Water Permeability and Sulfate Resistance of Eco-Friendly High-Strength Concrete Composed of Ground Bagasse Ash and Recycled Concrete Aggregate

摘要

This study is centered on the use of ground bagasse ash (GBA) and recycled concrete aggregate (R-CA) as raw materials to produce ecofriendly high-strength concrete (HS-C) with high durability. Specifically, GBA with high fineness was used as a replacement for cement up to 50%wt of the binder, and R-CA was used as a coarse aggregate to produce HS-C. The study involved investigating the water permeability and expansion due to the Na2SO4 solution present in the HS-C. The results revealed that R-CA had a clear negative influence on the durability of concrete. However, the expansion and the water permeability of recycled aggregate concrete (RAC) reduced when GBA up to 50%wt of cement was introduced as a replacement, and the values were lower than that of the conventional high-strength concrete (CT). Furthermore, the increase in the compressive strength of concrete resulted from the low incidence of capillary pores and pore connectivity in the cement paste, which was due to the filler effect of pozzolanic or hydration products, had significantly affected the reduction in water permeability, whereas the expansion of concrete was not significantly affected.