Residual bearing capacity of infilled frame of multi-ribbed composite wall after high temperature

摘要

Multi-ribbed composite wall structure (MRCS) is composed of densely distributed ribbed frames, including ribbed beams and columns and autoclaved aerated concrete (MC) filled inside ribbed frames. This paper investigates the temperature field and residual capacity of the infilled frame of MRCS after high temperature based on a combined experimental and finite element (FE) study. A series of axial compression tests were conducted to evaluate mechanical properties of MC, including compressive strength, elastic modulus and peak strain, subjected to high temperature. The constitutive relation of AAC after high temperature is defined based on stress-strain curves under different temperatures. Temperature field of the infilled frame under different fire loading schemes and the temperature of each node at different heating time are obtained from numerical analysis on basis of the thermodynamic performance of each material. Based on this, a Finite Element (FE) model for the infilled frame under diagonal loading is constructed, and the relationship between the residual bearing capacity and fire exposure time under different fire conditions is obtained. (C) 2019 Elsevier Ltd. All rights reserved.