Study on the post-fire axial compressive performance of the lightweight ceramsite foamed concrete sandwich composite shear wall

Abstract

This study is carried out to develop a new lightweight ceramsite foamed concrete sandwich composite shear wall, which is a new and affordable building system. The shear wall consists of two ordinary concrete wythes and a ceramsite foamed concrete intermediate sandwich layer between the wythes. Experimental investigation on five shear wall specimens is conducted by varying the parameters such as thickness of the ordinary concrete wythes and the insulation layer, reinforcement pattern and constrained component. Besides, by conducting fire test and axial compressive load test, the results are obtained, including the apparent phenomenon after fire, crack pattern and failure modes, load capacity, load-out of plane curve, strain distribution of the composite sandwich shear wall. The results show that sandwich ceramsite foamed concrete has good thermal insulation performance, and the compositeness of wythes and sandwich layer has reached in a certain degree. However, the compositeness of specimen using truss bars is weaken in the late loading stage and truss bars are advised to be used with the horizontal tie bars in practical engineering application. Compared with other specimens, the experiment ultimate strength has been increased by approximately 75 % by arranging the constrained component on the wall. Finite Element (FE) analysis is also conducted by ABAQUS and the results shows good agreement with experiment results, indicating that the FE model can be used to predict the behavior of the sandwich composite shear wall. Based on the existing methods, a modified method to calculate ultimate compressive bearing capacity after fire is proposed, with the maximum calculation error of 19 %, which shows that all methods can be applied to the practical engineering design.