INFLUENCE OF IN-SERVICE EXPOSURE CONDITION ON THE PERFORMANCE OF CONFINED CONCRETE

Abstract

RCC has not proved to be durable due to large number of factors. RC structures of the past have been constructed without ductile detailing, reducing their earthquake resistant capabilities. But nowadays every structural member is designed for certain amount of ductility. But eventually it is noticed that the changes that occur in the members induce reduction in the structural capacity of the member. With age, problems of durability are mainly attributed towards the corrosion of rebars in the structural members. A comparison of strength and ductile aspects of corroded short columns with two different types of confinement subjected to different levels of confinement and predamage levels were done, to create a better understanding of the behavior. The experimental programme consists of circular short columns with two different types of spacing for confining reinforcement, subjected to accelerated corrosion. Another set of specimens were preloaded to induce predamage before being subjected to corrosion. The testing of the specimens was under a constant strain for evaluating their behavior. The experimental results were analyzed for the effect of degree of corrosion, effect of degree of confinement and effect of predamage on the specimens. The results indicate that the response of the specimens with less confinement was substantially poorer than the closely confined specimens. The degree of corrosion caused reduction in the strength and ductile capacities of the confined specimens. Predamaging of the specimens also made some effects on the strength as well as the ductile behavior of the specimens. The effect of predamaging was more pronounced on the strength aspect than on the ductile behavior of the specimens.