Continuous Composite Beams under Fatigue Loading,

摘要

The results of fatigue and static tests of two continuous composite beams are reported. These results and earlier experimental results are compared with computer studies using a mathematical model to simulate the continuous composite member which has a cracked slab in the negative moment region. Satisfactory correlation was obtained between computer and experimental values for slab force,loads on shear connectors,and strain distribution in the cross section. The study reveals that the mathematical model can be satisfactorily used to evaluate the effect of changing the important parameters that influence the behavior of the negative moment region of the member. These parameters have been identified as area of longitudinal reinforcing steel,number of longitudinal bars,and spacing of shear connectors. It has been shown that the stiffness of the cracked slab in the negative moment region should be taken as the total area of the longitudinal reinforcing steel plus an effective area of concrete which is dependent on the parameters given above. It was found that a beam with one percent of longitudinal slab reinforcement in the negative moment region performed very well with shear connectors deleted from a large portion of the negative moment region. The stiffness of the slab in tension was found to be the area of longitudinal reinforcement plus approximately 20percent of the concrete area. (Author)