Experimental Study on the Shear Transfer in Joints of Precast Segmental Bridge

الملخص

This paper is concerned with the experimental study of shear strength and deformation of precast segmental bridge joints. The slip between the concrete segmental specimens, the failure mode of shear key and the horizontal movement between the segmental specimens are considered.The test groups consisted of ten segmental specimens casting by using two types of concrete (normal and fibrous). All specimens have the same cross section and reinforcement. The concrete compressive strength was varied between (22.5MPa) and (33.6MPa). The prestressing reinforcement consists of two (12.7mm diameter) seven-wire strands with ultimate tensile strength of (fu=1770MPa). The main parameters of the study were the number of shear keys, types of concrete and type of joint between segments.Test results show that the ultimate load increased for specimens with one, two and three shear keys were about (16.27%), (50.68%) and (60.87%) of the maximum ultimate load of reference specimens (without shear key), respectively. Also the deflection as well as the slip between segments of specimens was decreased by increasing the number of shear keys. When the level of prestressing stresses increases from (175MPa) to (524.2MPa), the load carrying capacity of the tested specimens increased by about (40%).