Influence of pre-static loads on dynamic compression and corresponding size effect of concrete: Mesoscale analysis

Abstract

Many concrete engineering structures have already withstood the historical loads (such as initial compressive/tensile load) prior to being subjected to dynamic loads. The historical load and structure size are two influential factors on dynamic mechanical performance of concrete. Exploring the dynamic size effect of concrete with different loading histories is a valuable task. In this work, the influence of pre-static compressive/tensile loads on dynamic compressive failure and the corresponding dynamic size effect was investigated by the developed mesoscale finite element method. The research results show that the dynamic compressive strength of concrete decreases with the increasing pre-static compressive load under low strain-rates while it increases with the increasing pre-static tensile load. Dynamic strength under high strain-rates is not affected by the pre-static loads. Moreover, as the concrete has withstood more pre-static loads, the dynamic size effect on compressive strength becomes more obvious under low strain-rates. Finally, the numerical results were analyzed and confirmed by the application of Weibull size effect law.