抄録
An experimental study was made to investigate effects of the strain rate on the fundamental mechanical properties of component materials of reinforced concrete structures, concrete and reinforcing bars. Dynamic compressive loading and splitting tests of concrete cylinders and dynamic tensile loading tests of steel reinforcing bars were performed under monotonic and cyclic loading with a prescribed strain rate of 0.00002 (or 0.00005; quasi-static), 0.005, 0.01, 0.025, 0.05, or 0.10sec^<-1> by using an electro-hydraulic servo-type testing machine. It has been clarified qualitatively and quantitatively that, in the dynamic loading tests of concrete cylinders, (1) the compressive strength, the tensile strength, and the elastic modulus of concrete increase with increasing the strain rate, and (2) either the geometrical configuration of stress-strain curves or the strain corresponding to the maximum stress is little affected by the strain rate. It has also been found that, in the dynamic tensile loading tests of steel bars, (3) increasing of the strain rate causes the increase of the yield stress and the strain at the beginning of strain-hardening, and (4) the elastic modulus, the behavior in the strain-hardening region and the strain at breakage are affected slightly by the strain rate. (5) There is no significant difference between the envelope curves of stress-strain relationships of repeated loading tests and the stress-strain curves of monotonic loading tests.
