Study On Optimization Design And Mechanical Performance Of Precast Concrete Wall Panels

Precast wall panels have a wide application prospect for its advantage of meeting the requirenments of energy conservation in building and housing industrialization. However, domestic research is still in the initial stage, so further research is needed to conduct to support its application in the practical engineering. Conventional precast wall panels can be divided into three layers, which are structural layer, thermal insulation layer and decorative-protective layer. The structural layer and decorative-protective layer are composed of concrete, meanwhile, the thermal insulation layer is composed of EPS boards. Shear ties are used to provide intergrity between the structural layer and decorative-protective layer. In this paper, optimization designs have been made for the precast wall panels. Then mechanical performance of precast wall panels is comprehensively studied. The specific contents are as follows:1. Optimization designs have been made for the precast wall panels. First of all, ceramsite concrete has been used in the decorative-protective layer, which can decrease the self-wight of the precast wall panels and increase the thermal performance of the precast wall panels. Secondly, a new type of shear tie with good mechanical properties and thermal insulation performance has been proposed. Then mechanical performance of shear tie was studied through experimental tests. The experimental results showed that the shear tie had suffient shear bearing capacity and tension bearing capacity. Considering the actual load of the shear tie in practical engineering, the test rests had enough safety stock. Projections were added in the both ends of the shear tie, which could increase tension bearing capacity and reduce the slip between the shear tie and concrete.2. The finite element software of ATENA was used to stimulate the in-plane mechanical performance and out-plane flexural property of the precast wall panels. The simulated results indicated that the lateral load of the precast wall panels got increase with the increase of the horizontal displacement when the precast wall panels had cooperative work with the main body structure, which is benefit to the seismic performance of the frame. Increasing the shear ties at the area of the supports could improve the flexural capacity of the precast wall panels. When the precast wall panels were in the bending limit state, the shear deformation of the shear ties didn’t reach the ultimate shear deformation. The precast wall panels were still at the elastic stage when the wind load were appied on the surface of the precast wall panels, which ensured the safty of the precast wall panels.3. The finite element software of MSC.MARC was used to stimulate the seismic performance of the frame. To testify the correctness of the frame’s skeleton curve simulated by the finite element software of MSC.MARC, the finite element software of ATENA was used to have static elastic-plastic analysis of the frame. Then a precast reinforced concrete frame with four precast wall panels was loaded under reversed cyclic loading to research on the seismic performance. The test results showed that the precast frame failed in flexural failure and no obvious destroying phenomena were observed in the areas of sleeve connection and joint connection. When the precast frame had relatively small lateral displacement, the wall panels would have a rotation around a vertical bolt, meanwhile, the other vertical bolt got off the frame. The four horizontal bolts had vertical displacement in the vertical slotted holes. The two precast wall panels in the horizontal and vertical directions didn’t ran foul of each other. In the elastic stage of the specimen, experimental results showed great agreement with the simulated results of MSC.MARC, which declared that the precast wall panels didn’t bear load together with the frame. With the increase of the lateral displacement of the frame, the specimen’s horizontal load from the experiment was larger than the simulated results in the elastic-plastic stage of the frame, which declared that the precast wall panels made some contributions to the seismic bearing capacity and lateral rigidity of the specimen and protected the specimen from collapse. At last, based on the experimental and simulated results, some suggestions of the specimen’s joint were proposed to ensure the precast wall panels’safty under rare earthquake.