Experimental Study On Heat Transfer Performance Of Autoclaved Aerated Concrete Self-insulating Block Wall

With the building energy conservation in all parts of the overall situation,as energy-saving wall of autoclaved aerated concrete self-insulation block has been attracting attention,and by the national policy to encourage and support,has broad prospects for development.In this paper,B06 grade autoclaved aerated concrete self-insulation block as an example,carried out the porosity,moisture content and autoclaved aerated concrete self-insulation block thermal conductivity of the relationship between the theoretical study carried out autoclaved aerated concrete self-insulation puzzle.The study on the heat transfer performance of the block wall is also carried out,and the relationship between the gray seam,plastering,wall thickness and heat transfer coefficient of autoclaved concrete wall is carried out.The main results of this paper include the following aspects:(1)The theoretical model of thermal conductivity coefficient of self-insulating block of autoclaved aerated concrete is obtained,and the following conclusions are drawn: The thermal conductivity of the model is obtained by comparing the calculated results with the measured value.And the thermal conductivity of self-insulating block of autoclaved aerated concrete decreases with the increase of porosity,which increases with the increase of moisture content.(2)The heat transfer performance test of autoclaved aerated concrete self-insulation block wall has the following conclusions: The measured value of heat transfer coefficient of autoclaved concrete block is 0.5~0.6 W/(m2·K).The heat transfer coefficient is lower than that of other materials,and the thermal insulation effect is better.The measured values of the heat transfer coefficient of the self-insulating block wall of the autoclaved aerated concrete in different forms are different.The measured value of the heat transfer coefficient of the self-insulating block wall of the concrete after the plaster is lower than the heat transfer coefficient before the plastering.(3)The results show that the micro-thermal bridge problem at the gray seam is significant,the type of mortar,the form of masonry,the thickness of the mortar is the same as that of the autoclave aerated concrete self-insulation block wall heat transfer coefficient has an impact.When the thickness of the mortar is thin(3~5mm),the choice of thin masonry mortar is appropriate,when the thickness of thick mortar(≤20mm),the use of insulation masonry mortar is appropriate;The way the wall insulation effect is good,the construction speed is fast,and the seismic performance is not weakened,the masonry way should be promoted;with the increase of mortar thickness,autoclaved aerated concrete self-insulation block wall Heat transfer coefficient also increases,the thicker mortar,micro-thermal bridge problem is more obvious,the greater the energy consumption of the wall;The correction coefficient of the thermal conductivity of autoclaved concrete with autoclaved aerated concrete is calculated,which provides theoretical guidance and calculation basis for building energy saving design.With the increase of the thickness of the plaster,the heat transfer coefficient of the autoclaved aerated concrete wall is reduced,the thicker the plastering,the better the insulation of the wall and the lower the energy consumption.With the increase of the thickness of the wall,the heat transfer coefficient of the autoclaved aerated concrete block wall is reduced,and the wall is thicker,the smaller the wall energy consumption is.