Study On Influencing Factors Of Heat Transfer Performance Of Recycled Aggregate Thermal Insulation Concrete

In order to respond to the call for building energy conservation policies in our country and improve the recycling rate of resources,the research group proposed a new type material of self-insulation which is recycled aggregate thermal insulation concrete(RATIC)for building structures.The concrete achieves the integration of insulation and the rational use of construction waste,and has important research significance and application value.The excellent thermal insulation performance of RATIC is the basis for realizing the goal of building energy conservation in China.The influencing factors of its heat transfer performance are studied in depth and the heat transfer mechanism is revealed,which can provide the necessary theoretical basis for further performance optimization and application of this concrete..In this paper,through the combination of experiment and simulation,the influence of the components of RATIC on the heat transfer performance of RATIC is studied.Based on this,the thermal resistance model of RATIC is established,and the RATIC Heat transfer mechanism is revealed from a mesoscopic level.The main research contents and conclusions are as follows:(1)Study on test methods for concrete heat transfer performanceBased on the existing hot box method and heat flow meter heat transfer performance test method,a new test method for heat transfer performance was improved and a new heat transfer performance index was introduced.Using a combination of experimental research and numerical simulation,the heat transfer performance of normal concrete slabs,RATIC slabs,and TIC slabs were compared and analyzed to verify the improved heat transfer performance test method,which is Feasibility and applicability.(2)Study on influencing factors of heat transfer performance of RATICThrough improved heat transfer performance test methods,the heat transfer performance of RATIC was studied by five factors: recycled coarse aggregate replacement rate,recycled aggregate size,glazed hollow bead content,water-cement ratio and steel volume fraction.The impact of the research shows that recycled coarse aggregate and glazed hollow bead can improve the heat transfer performance of RATIC,which is the main influencing factor of the heat transfer performance of RATIC.The ratio of water to cement and the size of recycled coarse aggregates have little effect to RATIC heat transfer performance,and the volume fraction of the steel will weaken the heat transfer performance of RATIC.(3)Research on heat transfer performance of recycled concrete based on microscopic modelBased on the theory of minimum thermal resistance,a thermal resistance calculation model based on the replacement rate of recycled coarse aggregate and the amount of glazed hollow bead was established to study the heat transfer mechanism of RATIC.This model can accurately predict the drying of RATIC during drying.The thermal resistance in the state can provide ideas for predicting the heat transfer performance of concrete.