Experimental study on axial compressive behaviors of prefabricatedcomposite thermal insulation walls after single-side fire exposure

The axial bearing capacity of prefabricated composite walls composed of inner and outer concrete wythes, expandable polystyrene(EPS)boards and steel sleeve connectors is investigated. An experimental study on the axial bearing capacity of four prefabricated composite walls after fire treatment is carried out. Two of the prefabricated composite walls are normal-temperature specimens, and the others are treated with fire. The damage modes and crack development are observed, and the axial bearing capacity, lateral deformation of the specimens, and the concrete and reinforcing bar strain are tested. The results show that the ultimate bearing capacity of specimens after a fire is less than that of normal-temperature specimens; when the insulation board thicknesses are 40 mm and 60 mm, the decrease amplitudes are 20.8% and 16.8%, respectively. The maximum lateral deformation of specimens after a fire is greater than that of normal-temperature specimens, and under the same level of load, the lateral deformation increases as the insulation board thickness increases. Moreover, the strain values of the concrete and reinforcing bars of specimens after a fire are greater than those of normal-temperature specimens, and the strain values increase as the thickness of insulation board increases.