Experimental study on the Fatigue Behavior of Loop joints

Precast deck system can ensure the quality of concrete decks, improve working environments for the workers, and reduce man hours outdoors and traffic disruption. However, in order to apply the precast deck to bridges properly, it is necessary to fully understand the structural characteristics of joints in precast decks. Particularly, since the bridge deck is under repeated loads such as traffic loads, fatigue behavior and characteristics of joints should be investigated. In this paper, fatigue behavior of loop joints was observed experimentally for diameter of loop bar, loop joint span and applied load ranges. Test results were analyzed to examine the current domestic design code for fatigue of reinforcement bar and serviceability under repeated loading. From the results, it is seen that the increasing of maximum displacement, crack width and strain in loop joints under repeated loading is similar to that in general RC beams if the loop joints have enough joint span.