Long-term performance of glulam-lightweight concrete composite beams with screw connections

Abstract

This paper presents the results of long-term shear tests on glulam-concrete screw connections and long-term bending tests on glulam-concrete composite beams. The influence of using lightweight aggregate concrete (LWAC) instead of normal concrete and the environmental conditions on the long-term performance of both shear connections and composite beams are evaluated. The experimental results show that the one-year creep coefficient of the screw connection using LWAC is about 1.2 times that of the screw connection using normal concrete, and the one-year creep coefficient of the screw connection tested in the outdoor environment is about 2.5 times that of the screw connection tested in the indoor environment. The overall growth trend of the long-term deflection of the composite beams using LWAC is quite similar with that of the composite beam using normal concrete. The composite beam with lower degree of composite action has more significant increase in the long-term deflection. The deflection of the composite beam tested outdoors increases much faster than that of the composite beam tested indoors. The superposition method of long-term deformation for TCC beams is verified by the experimental results and proved to predict the long-term deformation of TCC beams with good accuracy.