EFFECTS OF ENVIRONMENTS CONTAMINATED WITH CHLORIDES AND SULFATES ON RC COLUMNS

Introduction: Corrosion of steel reinforcement is a very complex process with clear differences in each geographical location. Many research models predicting the quality deterioration of reinforced concrete structures in areas contaminated with chlorides and sulfates are being developed around the world. However, these models still have a fairly wide application range and fail to accurately and fully reflect the reduction in structure quality in each specific condition. The purpose of the study was to survey the current status of reinforced concrete (RC) structures located in chloride- and sulfate-contaminated environments in coastal areas of Vietnam, analyze the result and compare it with previously researched proposals to clarify the impact of corroded steel reinforcement on the quality of RC columns. The following methods were used: Experimental Survey, Non-Destructive Testing, and Empirical Formula for determination of the deterioration of parameters including compressive strength of concrete, thickness of protective layer, diameter of reinforcement, and cross-sectional area of RC columns. In addition, this study was combined with the available recommendations on reinforcement corrosion to determine the residual physical and mechanical characteristics of concrete and reinforcement steel. As a result, the quality deterioration of RC columns with corroded reinforcement depends on the reinforcement location in the same longitudinal member. This indicates remarkable deterioration in the quality of structural sections that are regularly and directly affected by seawater.