Abstract:
The prefabricated composite insulation facade panel with groove is a new type of non-load-bearing external sandwich wallboard. The inner and outer leaf plates are made of aerated concrete, and the sandwich layer is made of polystyrene foam (EPS) insulation board. The groove on the top of the wall can be used as formwork for pouring concrete beams. The bearing capacity tests on 44 single panel joints and on 32 composite panel joints were carried out, respectively. Investigated are the effects of parameters such as the strength and the thickness of aerated concrete panel, the thickness of insulation board, the specification of gasket and strengthening measures etc., on the bearing capacity and on failure characteristics of single-plate and composite panel joint specimens. The results showed that: punching failure occurred in most of the specimens with circular gaskets; and increasing the thickness of slab and the strength of aerated concrete could greatly increase the bearing capacity of joints. For example, when the thickness of aerated concrete panel increased from 75 mm to 100 mm, the bearing capacity of single panel joints and of composite panel joints could be increased by 60% and 41.8%, respectively. The thickness of insulation layer hardly affects the bearing capacity of composite panel joints. Although increasing the diameter and the thickness of gaskets and installing transverse reinforcing bars could not significantly improve the bearing capacity of joints, they had obvious effects on enhancing the stiffness of joints and preventing brittle pull-out failure of joints. It is recommended that the diameter of gasket should be no less than 50 mm for composite insulation panel with a length of 3.15 m and 3.5 m, and that the thickness of gasket should be no less than 2.5 mm for panels with a length of 3.15 m and 3mm for panels with a length 3.5 m, respectively. Without reinforcement measures, the joint bearing capacity of ordinary composite insulation facade panel was similar to that of directly loaded single plate specimens. The bearing capacity of the joint could reach 1.7~2.1 times of the common composite panels joint, when strengthening steel pipes and gaskets were installed in the insulation board at both ends and in the middle of the specimens. The capacity of the composite insulation facade panels with gaskets at both ends of the strengthening pipes was significantly higher than that without gaskets.