Equivalent strength of unidirectional interval induced joints in RCC dams

The law of size effect for RCC fracture toughness was studied experimentally and this effect was introduced into the formula for calculating the equivalent strength of unidirectional interval induced joints in dams, which is related to the length of joints. It is found that the equivalent strength of unidirectional interval induced joint decreases with the increase of its length and increases with the reduction of strength grade under the condition of the same area reduction rate. It is also found that reduction rate of strength of the induced joints section decreases with the increase of strength grade of RCC and length of induced joint according to the curve of reduction rate of the induced joint section's strength. It is suggested that the length of induced joints should be relative long and the concrete intensity should be selected to be high grade when it is permitted.