Experimental Investigation of Silica Fume Effect on Durability of High Performance Concrete (HPC)

Chloride ions penetration in reinforced concrete (RC) structures causes serious problems linked to steel rebar corrosion, especially in maritime regions in Vietnam where environmental chloride ions content is much higher than standard value regarding corrosion problems. In this study, experimental investigation to determine durability capacity of HPC, regarding chlorine ion penetration, is performed in different conditions of chloride ion content in environmental water: laboratory condition, Ha Long Bay and Khanh Hoa region. Different doses of silica fume additive (5%, 10% and 15% replacing cement in concrete) are consequently examined on three HPC grades (C50, C60 and C70). Service life or durability capacity by mean of rapid chloride ions permeability measures, according to ASTM C1202 standard, at 365 days are analyzed. Experimental results show that 15% of silica fume additive replacing cement is the best dose to reduce chloride ions penetration for all studied maritime regions in Vietnam. Among three grades of HPC, C70 is more suitable in high environmental chlorine ions content regions and capable to stand against chlorine ions penetration much more than C50 and C60 HPC.