EXPERIMENTAL SERVICE LIFE PREDICTION OF REBAR-CORRODED REINFORCED-CONCRETE STRUCTURE

In the present investigation, an experimental methodology for service life prediction of rebar-corroded reinforced concrete (RC) structure h as been suggested. This methodology is based on the cumulative damage theory. The final failure is assumed to be the result of the effects o f the two modes of failure. The first mode considered is the natural c orrosion of rebar from the rime of depassivation followed by the secon d mode, which is the accelerated corrosion of rebar caused by anodic e lectrolysis under the impressed anodic current for a short period. The actual cracking of the specimens after applying an optimal anodic cur rent for a given period has been carried out by splitting under physic al load. Thus, a large intensity of. impressed current could cause cra cking by effect other than corrosion and a very small intensity of imp ressed current could take a long time for appreciable damage. The redu ction in failure tensile stress of concrete is correlated with intensi ty and duration of the impressed current, and from this relationship, the time required for cracking, under impressed current, is determined corresponding to the zero residual tensile stress at failure of concr ete. To demonstrate the utility of the suggested experimental methodol ogy, the service lives of a number of RC core-shaped specimens, having different corrosion rates and cover thicknesses, were determined and compared with the results obtained through another model suggested els ewhere in literature.