Research On Effects Of Construction Defects On Tensile Properties Of Half Grout Sleeve After High Temperature

With the promotion of prefabricated buildings by national policies,people pay much more attention to the safety of prefabricated buildings.In precast concrete structures,the joints between prefabricated components such as walls and columns are usually connected by grout sleeve splicing.Therefore,studying the mechanical performance of joints can effectively ensure the overall stability of precast concrete structures and prevent its progressive collapse.This paper is to research the effect of construction deficiency on tensile behaviors of half grout sleeve splicing after high temperature.The main contents are as follows:Sixty-seven half grout sleeve splicing specimens including those with different types of construction deficiency and without construction deficiency were produced and subjected to uniaxial tensile tests under room temperature,300℃post-high-temperature,and 600℃ post-high-temperature conditions.During tensile tests,the dynamic displacement of the sleeve section was collected by displacement sensors,and test force results were collected by the testing machine.Then the load-elongation curve of each test piece was made to analyze the various defect specimens after high temperature.Test results showed that horizontal defects of construction defects had a significant influence on tensile behaviors of half grout sleeve splicing specimens after high temperature,and these defects should be avoided as much as possible during construction.Nondestructive testing of ten half grout sleeve splicing specimens were carried out by X-ray apparatus.The X-ray apparatus effectively identified the inner grooves inside the sleeve,internal defects and the interface between the reinforcing bar and the grouting material and the sleeve wall.From the analysis and comparison of the test results,it was found that high temperature(600℃)will not lead to the change of the internal defects of specimens.Based on finite element software ABAQUS,the uniaxial tension simulation was performed on the partially defected specimens at room temperature and after high temperature conditions.The general contact definition between the grouting material and the sleeve was used to simulate the slip of the grouting material during the actual drawing process,and it was expand to research the distribution of the temperature field of the grouting material at high temperature.At the end of this paper,the construction defects of this experiment was summarized,and relevant reference suggestions were provided about the impact of construction defects on tensile behaviors of grout sleeve splicing after high temperature.