Structure And Properties Of Foamed Insulation Materials Based On Waste Ceramics

Among the existing building insulation materials,organic insulation materials were generally not resistant to aging,easy to burn,poor mechanical strength,and poor eco-friendly.However,the fiber materials in inorganic insulation materials were susceptible to deformation and harmful to the human body.Inorganic mortar had large bulk density and high thermal conductivity.Foamed cement materials need to consume a large amount of cement,which was not conducive to environmental protection and energy conservation.High-temperature foamed ceramics had high production cost and large material brittleness,while aerogel materials had narrow application fields.In view of the above problems,waste ceramics was used as the main raw material in this project,and the normal temperature foaming method was adopted to prepare new inorganic insulation materials.Firstly,the foaming and foam stability of foaming agents were studied,then the effects of structure and properties of the materials were investigated by setting different experimental parameters.Finally,the relationship between pore structure and properties of materials was discussed based on image method and fractal geometry.The results showed:(1)In this experiment,the waste ceramics accounted for 80wt.%of the solid content of the material to realize the recycling of waste ceramics.Compared with high temperature foaming method,normal temperature foaming method can effectively solve the problems of uneven pore distribution and wide pore size in the material.(2)The optimum comprehensive performance of the material was obtained at1000°C with 8wt.%foam,10wt.%clay and ball milling time of waste ceramics was 7h.The experimental results showed that the shrinkage rate of specimens was 3.71%,bulk density was 0.75g/cm~3,total porosity was 73.6%,compressive strength was 8.0MPa,and thermal conductivity was 0.113W/(m·K)at 200°C.(3)Using the image method to extract,binarize,and classify the pores,and obtain the pore structure parameters under different variables.The pore structure was analyzed by fractal geometry,and the pore structure with small fractal dimension was regular and tended to be circular.Reducing the porosity and the mean pore size and increasing the sphericity of the pores can improve the mechanical properties of the material.For the thermal conductivity,when the mean pore size was around 30?m and 50?m,the effect of the increase of porosity on the thermal conductivity of the specimen is more effective than the reduction of the pore diameter.