Strength of Corroded RC Beams with Bond Deterioration

The paper proposes strut and tie models for the flexure, shear, and bond strength of corroded reinforced concrete (RC) beams. The deterioration of the material properties including bond and the cross section losses are modeled. Generalized corrosion and pitting are considered. The models are verified with the experimental data of simply supported beams with transverse stirrups subjected to three- or four-point bending, which shows the reduced capacity and changes of failure modes caused by the deterioration. The main innovative contributions consist in a consideration of bond deterioration effects in strut and tie models of corroded beams with different shear span-to-depth ratios and the verification of the models by comparison with tests from different campaigns related in the literature that used either natural corrosion, environmental corrosion under load, or slow artificial corrosion. In addition, the fib Model Code 2010 provisions for bond and its deterioration due to low and medium corrosion levels are used and extended for higher corrosion levels; practical choices for cross section losses are defined.