ABSTRACT
Recent experimental works on concrete fatigue show that there is a significant increase of load-induced temperature in ultra-high performance concrete, especially for high loading rates. The temperature field is not uniformly distributed in concrete which causes internal stresses and leads to a reduction of concrete fatigue strength. The main issue to be examined is the mechanism of heat-generation in concrete due to cyclic loading. In this paper, the development of load-induced temperature is modelled by a heat transfer equation. The heat generation rate is theoretically determined and experimentally validated. The influence of the load frequency and the maximum size of aggregate of concrete on the temperature development and on the fatigue behaviour of concrete is also taken into account. The obtained results show that the load-induced temperature is generated by conversion of plastic work, which mainly occurs at the interfacial transit zone between cement paste and concrete aggregates.
