| Recycled thermal insulation concrete is a new building material made on the basis of ordinary concrete,using recycled aggregate from waste concrete crushing to replace natural aggregate and adding vitrified beads as thermal insulation aggregate.On the basis of meeting the bearing capacity,it achieves the effect of building energy saving and green environmental protection,which is in line with the trend of social development.The addition of recycled aggregate effectively alleviates the shortage of domestic resources;The addition of glazed bead thermal insulation aggregate can play the role of internal thermal insulation of building structure,so as to reduce the design of external thermal insulation of building components and achieve the effect of energy conservation and environmental protection.In this paper,based on the research of recycled thermal insulation concrete,this new material is introduced to the building components,and the bending performance of recycled thermal insulation concrete beam is studied.Combined with ABAQUS finite element software,the nonlinear simulation analysis of the test beam is carried out to study the different replacement rate of coarse aggregate,different reinforcement ratio,different reinforcement ratio,and so on The influence of web reinforcement or not on the failure mode and mechanical characteristics of recycled thermal insulation concrete beams is studied.In this paper,the research results of flexural capacity of recycled thermal insulation concrete beams can be applied to engineering practice,and provide the basis for the formulation of relevant specifications of mechanical properties of recycled thermal insulation concrete beams.The results of this experiment are as follows:1.Design and manufacture three groups of recycled thermal insulation concrete beams with different replacement ratio of coarse aggregate,different reinforcement ratio and with or without web reinforcement,observe the failure mode of each group of beams,measure the mid span deflection,reinforcement strain,concrete strain and bearing capacity of each group of beams after loading,and analyze the influence of different replacement ratio of coarse aggregate,different reinforcement ratio and with or without web reinforcement on the bending bearing capacity of recycled thermal insulation concrete beams,This paper reveals the failure mechanism of recycled thermal insulation concrete beams,and also provides the basis for the long-term deformation performance of recycled thermal insulation concrete beams.The test results show that the addition of vitrified beads increases the ductility of recycled thermal insulation concrete beams,and the deflection of recycled thermal insulation concrete beams is larger than that of ordinary concrete beams;Under the same replacement ratio of coarse aggregate,increasing the longitudinal reinforcement ratio can increase the flexural capacity of recycled thermal insulation concrete and reduce the deflection of the beam;When the beam without web reinforcement is close to the ultimate load,the concrete on the upper part of the beam will fall off rapidly,showing brittle failure,which is not suitable for engineering application.2.Considering the influence of recycled coarse aggregate and thermal insulation coarse aggregate,the calculation formula of bearing capacity of ordinary concrete beam is modified,and the calculation formula of normal section bearing capacity of recycled thermal insulation concrete beam is obtained,and the mid span deflection and maximum crack width under ultimate load are checked.The results show that the experimental values are basically consistent with the calculated values,which can ensure the safety of the building structure.3.ABAQUS finite element software is used to simulate and analyze the bending performance of recycled thermal insulation concrete beams,and the simulation results are compared with the test results.The results show that the damage of concrete test beams is symmetrical,and the change of midspan deflection is close to the test results.With the increase of recycled coarse aggregate,the midspan deflection increases gradually,and the difference between the ultimate deflection and the measured deflection is 8.9%. |
