Structural assessment of corroded self-consolidating concrete beams

Abstract

The structural performance and cracking behavior of corroded reinforced concrete beams made with self-consolidating concrete (SCC) were investigated and compared to those of normal concrete (NC) beams. Six reinforced concrete beams without web reinforcement (400 mm wide × 363 mm deep × 2340 mm long), designed to fail in shear, were tested after being subjected to accelerated corrosion. The beams were partially immersed in sodium chloride solution, then subjected to an impressed current until they reached three levels of corrosion (0%, 10%, and 30% theoretical mass loss). They were then tested under mid-span concentrated load until failure. The performance of the corroded SCC/NC beams was evaluated based on the results of crack patterns, crack widths, loads at first flexure and first diagonal cracks, mid-span deflection, ultimate load, and failure modes. In addition, the resulting crack widths and mid-span deflections were compared with the predictions of several major code-based equations. The results showed that at severe corrosion level, the failure mode for the SCC beam had changed from shear failure to anchorage slipping failure. This result was attributed to the increase of the corrosion concentration at the far end corners of the SCC beam, located far away from the casting point, due to poor quality concrete resulting from insufficient compaction. For designers considering SCC for structural applications, the recommendations in this paper may be particularly useful.