Load Rate Effects on Concrete Compressive Strength

Plain concrete cylindrical specimens from six different concrete mixes, 51 mm in length and diameter, were tested in compression quasi-statically at strain rates between 10 -6 /sec and 10 -5 /sec in a standard MTS machine, and dynamically at strain rates between 1/sec and 300/sec in a Split Hopkinson Pressure Bar (SHPB). The results of these tests indicate a true strain rate sensitivity of the pertinent concrete material strength parameters such as compressive strength, strain at maximum compressive stress, and ultimate compressive strain. Complete stress-strain curves for various concrete strengths at a broad range of strain rates have been generated from the experiments which clearly illustrate the strain-rate sensitivity.