The Research Of Producing Green Insulation Energy-saving Wall Material Incorporating Large Amounts Of Urban Sludge

China’s urban sewage sludge production is huge,and the sludge is harmful to the natural environment and the human body.The use of sludge combined with other solid waste to prepare green energy-saving insulation building materials is a good sludge treatment method.This treatment has minimal impact on the environment and can produce building materials that are urgently needed in the construction industry.However,wall materials made by sludge generally have the characteristics of poor thermal insulation properties and low sludge incorporation.To solve this problem,the paper uses sludge combined with other solid waste to prepare green high-performance fired insulation bricks.The main research contents and research results are as follows:(1)Using sludge as a pore-forming agent and muck as a matrix to prepare sintered insulation bricks with different sludge contents.With the increase of sludge content,the total shrinkage of sintered bricks decreases,the sintering shrinkage increases,the thermal conductivity and compressive strength decrease,and the water absorption of bricks increases.According to the research purpose and experimental conditions,40% was determined as the most suitable dosage of sludge.With 40% sludge,the sintered brick has a thermal conductivity of 0.184 W/(m·K)and a compressive strength of less than 3 MPa.(2)Hollow glass fiber was used to instead the clay form brick manufacturing.Under the action of the glass fiber and the borax,the strength of the fired brick is obviously increased and bulk density almost have no change due to the anti-shrinkage of the glass fiber,and the thermal conductivity increases slight.The compressive strength and thermal conductivity of fired brick with 40% sludge 10% hollow glass fiber and 4% borax was 10.11 MPa and 0.233W/(m·K).The rice hull ash with lower thermal conductivity was used to instead the clay and rice hull ash incorporation did bring a good properties to bricks.Sodium chloride is used as a flux and part of sodium chloride moves with moisture to the surface of the brick to form a flux concentration gradient.The optimum sodium chloride content was determined,then firing temperature was improved to further optimize the performance of the fired brick.When the sodium chloride incorporation amount is 3% and the brick is kept at the fired temperature1075℃ for 2 h,the strength of the fired brick reaches 8.01 MPa and the thermal conductivity was 0.189 W/(m·K).In addition,coal gangue can be used as a flux and pores former,and the relationship between the doping amount of coal and the performance of fired bricks was explored.The sintered insulation brick with 40% sludge content,10% rice hull ash and 5%coal sintered at 1075℃for 2h has a good quality whose compressive strength was 9.5 MPaand thermal conductivity was 0.194 W/(m·K).(3)This paper designs a superior brick hole distribution according to the relevant brick hole design principle.The thermal conductivity of porous brick made by previous sintered insulation brick and the superior brick hole distribution was simulated by finite element simulation software.The comprehensive thermal conductivity of the insulating bricks were0.157 W/(m·K),0.127 W/(m·K),and 0.129 W/(m·K),respectively.In summary,this paper completed the whole research of sintered porous insulation brick including sludge sintering brick producing,performance optimization,brick hole distribution design.This paper prepared sintered porous thermal insulation brick with excellent comprehensive performance,increasing urban sludge disposal efficiency.