Performance of very-high-strength concrete subjected to short-term repeated loading

The effect of short-term repeated loading on very-high-strength concrete pr isms of various sizes has been experimentally investigated. Concrete batche s made of local materials were cast using different types of coarse aggrega te. The level of cyclic preloading was altered and the corresponding influe nces on the ultimate strength, strain and modulus of elasticity were monito red. The effect of changing the number of cycles at a certain preloading le vel was investigated. For certain loading levels the number of cycles to fa ilure was observed. The size of the specimens tested was noted to have a si gnificant effect on the stress-strain parameters. Behavioural modelling usi ng the concepts of continuous damage mechanics was conducted. On the basis of the experimentally observed behaviour, a mathematical expression for the damage variable was derived. Simulation by the proposed damage model captu red most of the salient features of the response such as the effect of cycl ic preloading at different levels, the number of cycles to failure in fatig ue tests and the stress-strain curves.