MOISTURE AND STRAIN-RATE EFFECTS ON CONCRETE STRENGTH

The effects of strain rate and the coupled effects of moisture content and strain rate on concrete strength are experimentally investigated. Dry concrete exhibits clearly defined strain rate transition regions for both tension and compression. Significant strength increases in dr y concrete are observed only at strain rates above the transition regi ons. Wet concrete, however, experiences appreciable increases in stren gth at strain rates both below and above the dry concrete transition r egion. An analytical expression has been derived that accurately predi cts the tensile fracture strength of dry concrete. This expression can be modified to account for moisture content in concrete.