Experimental investigation on flexural performance of corroded RC beams with high-strength concrete and steel bars

Abstract

The flexural performance of corroded reinforced concrete (RC) beams has been well studied experimentally during the past years. In the available experiments, however, the specimens are commonly designed with the strengths of steel bars and concrete below 400 MPa and 40 MPa, respectively. Therefore, the effect of high-strength concrete and steel bars on the flexural performance of corroded RC beams has not been examined due to limited experimental data. In this study, a total of 15 RC beam specimens were fabricated with high-strength of concrete (i.e, cylindrical compressive strength greater than 42.0 MPa) and steel bars (i.e., yield strengths exceeding 420 MPa). The low-to-high corrosion ratios of 0 %, 6 %, 8 %, 10 % and 12 % were considered by using accelerated corrosion processes. For each of the beam specimens, the flexural performance was tested by arranging four-point bending loads. The experimental results reveal that high strengths of concrete could reduce the corrosion-induced crack width. Beams with higher strength grade HSSB exhibit a more pronounced decrease in load-bearing capacity under the same corrosion damage degree, whereas the application of higher strength grade HSC can mitigate the deterioration of flexural capacity. However, beams with higher strength grade HSC demonstrate significant deterioration in deformation capacity after corrosion. Finally, the flexural load-bearing capacity of the corroded high-strength RC beams was evaluated using the available empirical models. It is found that the prediction model proposed in EN 1992 code could yield the most accurate results for the tested specimens by incorporating the effects of corrosion and high strengths of concrete and steel bars.

Keywords

• RC beam
• High-strength steel bars
• High-strength concrete
• Steel bar corrosion
• Flexural load bearing capacity model