An Experimental Study On The Corrosion-Induced Cracking And Mechanical Performance Degradation Of Reinforced Concrete Slabs

Reinforcement corrosion is the most important factor influencing the durability of concrete structures. The reinforcement corrosion mechanism, corrosion rate, and mechanical performance degradation of corroded concrete members has become one of focuses in the current durability study of concrete structures. In practice, concrete structures are subjected not only to static loads but also to repeated loads.In this thesis, the effects of the water/cement ratio, cover depth, and reinforcement spacing on the time to surface cracking of reinforced concrete slabs are evaluated by combining electrochemically accelerated corrosion tests with theoretical analyses. The flexural rigidity degradation under repeated loads and the ultimate bearing capacity under normal loads are studied for corroded reinforced concrete slabs. The conclusions of this study are summarized in the following points: (1) Under given conditions, the time to surface cracking can be prolonged to various extents by increasing the water/cement ratio, cover depth, and reinforcement spacing.(2) When steel bars are corroded, increasing the water/cement ratio, cover depth, and reinforcement spacing can slow down the rigidity degradation rate of slabs under repeated loads but decrease the ultimate bearing capacity of slabs.(3) Under repeated loads, the bond strength between steel bars and concrete is the primary factor that affects the flexural rigidity of tested slabs in the first few cycles. As the number of cycles increases, the reduction in the cross-sectional area of steel bars and the material performance degradation become the primary factors.(4) The larger the repeated loads are, the more rapidly the flexural rigidity and ultimate bearing capacity of slabs degrade.