INFLUENCE OF TENSILE INDUCED MICROCRACKING ON STANDARDIZED PERFORMANCE TESTS

摘要

Performance specifications require evaluation of explicit characteristics that can be measured quantitatively. One of the considerable issues in the process is determining the point of performance; when and where properties are measured. Conventional "end of delivery chute tests" do not necessarily reflect placed concrete. In addition, test specimens collected are often stored in near-optimal conditions. In this research, the influence of load induced microcracking on the mass transport properties of concrete was investigated. Ultrasonic pulse velocity technique was used to quantify the extent of internal damage. Results indicated that propagation of interconnected mortar cracking as a result of split tensile loading beyond 80 % of the ultimate strength will increase the amount of water absorption (ASTM C1585) and electrical conductivity (ASTM C1760) of concrete significantly which may lead to the differences in accepting tolerances of this defect in the field.