Study On Rockwool Composite Board Used For External Thermal Insulation Of Building Exterior Wall

This paper studies the problem of building energy saving caused by the larger energy consumption in the building industry.In order to make up for the traditional organic insulation material is not fireproof defects need to replace the organic insulation board with a non-combustible inorganic insulation board.The object of this study is the external insulation structure of external wall with rock wool as insulation material.According to the properties of rock wool and its failure mechanism under external action,the material and packaging method for rock wool insulation board are designed,and the thermal performance of rock wool composite board is analyzed.In this study,cement-based material(mortar)will be used to encapsulate the rock wool core material with six sides to make the rock wool composite board,so as to achieve the purpose of isolating the external environment medium.In order to find out the influence of water-binder ratio,fly ash and silica fume content on the durability of encapsulation mortar more effectively,a three-factor,three-level orthogonal test was designed to optimize the mixture ratio of encapsulation mortar,so as to meet the preconceived performance requirements.The freeze resistance of encapsulation mortar was studied through freeze-thaw cycle test,the influence of drywetting cycle on encapsulation mortar was studied through dry-wetting cycle test,and the impermeability of specimens was evaluated through water vapor penetration test.The test results show that the remixing of 7.5% silica fume and 20% fly ash at a waterbinder ratio of 0.55 is the most effective way to improve the durability of packaging materials,and this conclusion is applied to the subsequent experimental studies.In order to further improve the mechanical properties and durability of the cement-based packaging layer mortar,the modification method was explored on the basis of completing the optimized cement based packaging layer mortar mix ratio design.Firstly,the influence of the amount of entrapment agent on the specimen was investigated,and the amount of entrapment agent was determined according to the change of mechanical properties of encapsulation mortar.It explored the influence of early carbonation curing on the specimen and concluded that early carbonation curing was not conducive to the development of specimen strength.The freezing-thawing cycle,dry-wetting cycle,water vapor permeability,pore analysis and microscopic pore structure of hardened mortar specimens were studied.The results show that adding 0.01% air-entraining agent as the modification scheme can indeed improve the frost resistance and impermeability of mortar specimen,and can reduce the influence of dry-wet cycle on encapsulation mortar.The packaging method of rock wool core material adopts six sides packaging method.On the basis of determining the mortar mix ratio and modification scheme of encapsulation layer,the overall performance of rock wool composite board was explored.Glass glass bead insulation mortar has the advantages of low density and low thermal conductivity,and is widely used in external wall insulation structure.The vitrified microsphere insulation mortar was used as the encapsulation mortar of rock wool composite board as the control group.By testing the tensile strength and water permeability resistance of the composite board and the simulation of thermal performance by COMSOL software,it can be concluded that the air-entraining agent modified mortar is more suitable for the packaging of rock wool core material.