The performance of old and the new concrete construction depends upon bond strength between old and the new concrete. Current adhesive and strength measurement method ignores the effect of stress concentration from shape of specimens. Therefore, this ...
The performance of old and the new concrete construction depends upon bond strength between old and the new concrete. Current adhesive and strength measurement method ignores the effect of stress concentration from shape of specimens. Therefore, this research calculates stress concentration coefficient as the ratio of drilling depth to drilling diameter(h_s/D), the ratio of overlay thickness to drilling diameter(h_o/D), the ratio of steel disk thickness to drilling diameter(t/D), the ratio of overlay elastic modulus to substrate modulus(E_l/E_0), the distance from core to corner border(L_corner) and the distance between cores(L_core) vary. The finite element method is adapted to analysis. The results from the F.E.M analysis are as follows : The stress concentration effects can be minimized when the ratio of drilling depth to drilling diameter(h_s/D) is 0.20∼0.25, the elastic modulus ratio(E_l/E_0) is 0.6~1.0, and the ratio of steel disk thickness to drilling diameter(t/D) is 3.0. The overlay thickness, the distance from specimens to corner border(L_corner), the distance between cores(L_core) almost do not affect to the stress concentration.