BENDING AND SHEAR CAPACITIES AND DURABILITY OF CRAMP JOINT AT PRE-CAST HIGHWAY DECK SLABS

摘要

A new jointing method using steel cramps with a unique configuration was developed for the field joint of pre-cast deck slabs of highway bridges. In this jointing method, the looped distribution bars are connected by the cramps to the main reinforcements. Therefore, the joint can transfer the bending moment and shearing force through the interlocking effect caused by the cramps, and it is both excellent in installation on-site and economical compared with the loop joint currently in use. In order to confirm the bending and shear capacities and durability of the joint, and to clarify the failure mechanism of the joint, a series of static loading tests and fatigue tests using full size beam specimens formed in the distribution bar direction were carried out. From the results of these experimental studies, it was clarified that the cramp joint has enough load carrying capacity being equivalent to the loop joint. Furthermore, for the durability of the joint, it is confirmed that the joint has a practical use because a decrease of the bending and shear rigidity due to repetition of loading is almost the same as the one of the loop joint under the design wheel load level.