An experimental investigation of pre-loading effects on the dynamic behaviour of concrete

摘要

The effects of pre-loading on the dynamic behaviour of concrete were experimentally investigated in a series of split Hopkinson pressure bar tests. Cylindrical specimens with three water/cement ratios and two kinds of aggregates were tested. The effects of pre-loading and strain rates on the dynamic stress-strain relationship, strength, energy absorption capability and failure modes were investigated. The results showed that when the pre-loading was smaller than 30% of the static compressive strength, its effect on dynamic strength could be ignored. However, a 29% reduction in dynamic strength was observed when the pre-loading was higher than 40% of the static strength. In addition, the pre-loaded specimens exhibited greater strain-rate dependence. An empirical model considering the effects of pre-loading and strain rate was developed based on the test data.