Exploratory Study of Shear Strength of Joints for Precast Segmental Bridges

The joints between the precast segments are of critical importance in segmental bridge construction. They are critical to the development of structural capacity by ensuring the transfer of shear across the joints and often play a key role in ensuring durability by protecting the tendons against corrosion. However, construction of the joints must be simple and economical. A number of types of joint configurations have been used in various precast segmental bridges in the United States, although relatively little information is available on the behavior and design of such joints. This study reports on a modest scope experimental investigation to determine the relative shear transfer strength across different types of joints typically used between adjacent segments of precast segmental bridges. The types of joints considered included no keys, single large keys, and multiple lug keys. Both dry and epoxy joints were tested. The test results indicated substantial differences in the strength at a given slip in the various types of dry joints, but indicated that all types of joints with epoxy essentially developed the full strength of a monolithically cast joint.