| The Integration of Reinforcement and Formwork（IRF）shear wall system is a new type of structural system which uses 20mm high performance fiber mortar slab as formwork on two sides,with the reinforcement cage placed between the formworks.It has many advantages such as lighter weight,easier to transport and install.This paper has carried out experimental study and theoretical analysis of the IRF shear wall.The main work and results are as follows:1)Two cast-in-place reinforced concrete shear wall specimens with different thicknesses and five IRF shear wall specimens were designed,and pseudo-static tests were carried out,researches show that:Bending failure occurred in all specimens,the reinforcements were tensiled to yield and the concrete collapsed and peeled off.But there are slightly different between the IRF specimens and the cast-in-place specimens in the failure modes:the wall crack width is larger in the cast-in-place specimens.While the wall crack width is smaller in the IRF specimens,and the crack width is larger at the horizontal joint in the later loading period.The bearing capacity,stiffness and ductility of the standard IRF specimen are better than the 200mm thickness cast-in-place specimen’s,which are equivalent to the the 240mm thickness cast-in-place specimen’s.The integrity of mortar slab and the post-cast concrete is favorable and no peeling is found throughout the loading process.The farmwork and concrete can work together as a whole,satisfied the requirement of"equivalent cast-in-place".The internal surface of formwork treated with a brushed surface or reduce the space between connectors can improve the performance of formwork-concrete interface,delay the development of crack,which have basically no effect on the bearing capacity,stiffness and ductility of the specimens.The structure of standard IRF specimen meet the mechanical property requirements.Increase the section area of longitudinal reinforcement can improve bearing capacity and stiffness of IRF specimen,but have no effect on the performance of formwork-concrete interface.The specimen with thermal insulation has the same mechanical performance as the standard IRF specimen,and the mortal farmwork covered the thermal insulation can work together.2)The finite element simulation of the IRF specimens were carried out by Abaqus software,and the finite element models are in good agreement with the experimental results.Based on the reliable finite element model,the mechanical behavior of the IRF shear wall with different axial compression ratios is analyzed.The results show that increasing the axial compression ratio can increase the bearing capacity of the specimens,but decrease the ductility.3)Based on the reliable finite element model,the influence of different splice forms on the mechanical performance and horizontal joint performance of IRF shear wall specimens.The form of the length of splice reinforcements from buttom beam to loading beam has the same bearing capacity as the standard structure,which can effectively reduce the opening displacement of the horizontal joint,but will reduce the ductility of the IRF shear wall.The form of increase the section area of splice reinforcements of the boundary elements can improve the performance horizontal joint,increase the bearing capacity of the wall,and have little effect on the ductility.The super-strength coefficientλ0 should not exceed 1.46. |
