Evaluation of the compressive strength of concrete under combined force and chloride load.

The degradation of reinforced concrete (RC) in aggressive environments is caused by a combination of factors ranging from force loading to weathering, to various chemical agents. Reinforcement corrosion in RC structures caused by excessive chloride ion diffusion is then one of the highly critical factors related to the potential destruction of this construction. Considering these facts, it is highly desirable to investigate the behaviour of concretes under a combination of force and chemical loading. The present study thus provides the basic results of an experiment in which laboratory concrete specimens were first subjected to partial loading in a press machine, then immersed in a fully saturated salt solution, and in the last step the compressive strength was determined. The loaded specimens were compared with specimens without the first loading and also with specimens immersed in normal water. This makes it possible to evaluate the combined effect. The results were evaluated also with respect to the strength increase under maturation of concrete in time. The results showed that concrete immersed in water after initial partial loading has a lower ultimate strength. Then, concrete without preloading force but immersed in chloride solution showed lower values and concrete preloaded and immersed in chloride for 90 days had the worst residual strength result. [ABSTRACT FROM AUTHOR]