Shear test on joints between precast post-tensioned units

Shear tests on three types of joint between precast post-tensioned units have given data from which the minimum shear strength of these joints may be calculated. The minimum value of the coefficient of friction of the surfaces at a plain butt joint was found to be 0 391 and that of the surfaces at a mortar joint 0 645.

The results obtained when testing rejoined cracked members are discussed, and an analysis is made which is consistent with the mode of failure.