抄録
Many indirect tensile test methods have been proposed for concrete, because the direct tensile test has various difficulties in applying it to concrete. However, the biaxial stress state and/or the sharp stress gradient occur in the specimens used in the usual indirect tensile tests. Therefore, it may be difficult to obtain tensile stress-strain curves of concrete by the usual indirect tensile tests. This study aims at examining the applicability of a tensile test method with frame specimens to concrete by clarifying the stress distributions in the specimens at loading by FEM analyses. The FEM analyses showed that the stress in the horizontal bar of frame specimen was uniform and uniaxial when a suitable shape of frame specimen was adopted. The experimental results showed that loading was extremely easy in the test method with frame specimens as compared with that of the other tensile test methods of concrete. It was also found that the tensile strength and the modulus of elasticity of concrete obtained by the method with frame specimens agreed with those obtained by the direct tensile test method. These facts suggest that the test method with frame specimens can conveniently be used in the fatigue and creep tests of concrete under tensile loading.
