Mechanical behaviour of corroded reinforced concrete beams - Part 1: Experimental study of corroded beams

Steel corrosion in reinforced concrete leads to crack occurrence along the reinforcement (secondary cracks), to a reduction in bond strength and a red uction in steel cross section. The purpose of this study is to determine th e effect of these deteriorations on the global behaviour of reinforced conc rete structural elements in their service and ultimate states. Mechanical e xperimentation was carried out on fourteen-year-old reinforced concrete bea ms, on two control elements and two corroded beams. A comparative analysis of the results obtained on the beams showed that concrete cracking in the c ompressive area had no significant influence on the behaviour in service of the corroded elements. However, significant modifications of service behav iour were observed, due to the degradations in the tensile zone, namely: lo ss of bending stiffness, dissymmetrical behaviour. Finally, the measure of the residual steel cross-section of the corroded re-bars showed that the lo ss of bending stiffness due to steel corrosion cannot be merely explained i n terms of steel cross-section reduction. Concerning the ultimate behaviour , the loss of steel cross-section is the main parameter which leads to a re duction of bearing capacity and ductility. Another part will explain the se parate and coupling effects of bond strength and steal cross-section loss o n the mechanical behaviour of corroded beams.