Research On Eliminating Building Thermal Bridge By Biomass-based Components

With the continuous development of urbanization in China,the demand for buildings continues to increase,and the proportion of building energy consumption in social energy consumption is also increasing.Prefabricated buildings have the characteristics of energy saving,high efficiency and recycling,which is a major trend in the development of the construction industry.However,due to the special structure and construction methods of prefabricated buildings,the thermal bridge effect at the junctions of the components of the outer envelope structure is particularly obvious,which leads to concentrated heat loss,and even affects the building structure and indoor environment quality,and limiting the development of prefabricated buildings and application.This research proposes a building thermal bridge elimination component that can be applied to the connection between the floor slab and the exterior wall.The component is made of a new type of biomass insulation material as the basic material,and the external surface is treated with a waterproof coating and an adhesive coating to make it have Multi-objective performance such as waterproof,moisture-proof,and adhesion.The research uses experimental research to analyze the waterproof performance,moisture-proof performance and bonding performance of the new component;and uses ANSYS Fluent simulation analysis software to simulate the steady-state heat transfer to analyze the thermal insulation performance of the new component and the influence of component design parameters on the thermal insulation performance.The research results show that the building thermal bridge elimination component have good thermal insulation performance in different application scenarios,which can effectively reduce the infl uence of the thermal bridge at the connection between the external wall and the floor slab of the prefabricated building,and increase the temperature of the area affected by the thermal bridge by 2.9℃ to reach the temperature of the normal part of the external wall.And the water absorption rate and moisture absorption rate of the components are significantly reduced after the waterproof coating on the outer surface of the thermal bridge insulation component of the building,the water absorption rate is reduced from 35.7%to 18.5%,and the moisture absorption rate is reduced from 7.0% to 2.1%.After the outer surface of the adhesive coating treatment,the component and the concrete material have a strong bonding force,the bonding strength meets the requirements of the material,and the shear strength of the bonding site can reach 0.536 MPa.In addition,the thermal bridge thermal insulation component of the building also has good weatherability and fire resistance.This research provides a solution to the thermal bridge problem of the prefabricated building envelope,and has the advantages of simple preparation process,low construction difficulty,and excellent multi-objective performance.It is of great practical significance to improve the large-scale application of prefabricated buildings.