The Research And Development Of New Low-temperature Foam Glass Ceramic Composite Building Insulation Materials

Building energy consumption accounts for more than 30%of total energy consumption,so building energy efficiency is very important.Using wall insulation materials is one of the effective measures to achieve the goal of saving energy,but it has faced many difficulties in construction practice for a very long time.Organic insulation materials occupy 90%of the market due to their light weight and low thermal conductivity(0.022-0.04 W·m-1·K-1),but the poor fire performance leads to huge safety hazards,the frequent building fires alarm for building fire prevention.Inorganic insulation materials have attracted attention due to their fire resistance and good durability.However,foam concrete,foam glass,and foam ceramics in the market have the disadvantages of large density,high hygroscopicity,and high energy consumption for making.Therefore,there is an urgent need for a high-performance insulation material that combines the advantages of organic and inorganic insulation materials.In the early stage,a low-temperature foam glass material was prepared by colloidal chemical method.The density was as low as 70 kg/m3,the thermal conductivity was less than 0.05 W/(m·K),the thermal insulation performance was close to that of organic thermal insulation materials,and the fire resistance was good and the foaming temperature was low.However,the material was only heat treated once,the hydroxyl groups in the system were not completely removed,and the residual hydroxyl groups broke out the glass network and were hydrophilic,which making the material poor in water resistance.In this paper,a new low-temperature foam glass ceramic composite thermal insulation material is proposed.The Na2O-B2O3-Al2O3-SiO2-H2O hydrated glass sol matrix,externally mixed crystal mineral powder and chopped glass fiber are used for foaming under a low temperature.And then heated under a high temperature to get rid of the hydroxyl,finally,we get the low-temperature foam glass ceramic composite thermal insulation material.The main research contents and conclusions are as follows:(1)Successfully prepared low temperature foam glass ceramic composite insulation materials.The Na2O-B2O3-Al2O3-SiO2-H2O hydrated glass sol was prepared by colloidal chemical method,and the crystal phase mineral powder fly ash and chopped glass fiber were mixed with the two steps eat treatment to obtain a new low-temperature foam glass eramic composite thermal insulation material.(2)Exploring the modification mechanism of fly ash and chopped glass fiber.The crystal in the fly ash are mutually overlapped,and the glass fibers are supported by the skeleton to increase the strength of the pore walls,which reduces the volume shrinkage problem accompanied by the decrease of the hydroxyl content of the material during the high temperature heat treatment;The fly ash reacts and produces[SiO4]tetrahedrons,which improve the integrity and tightness of the glass network,and then improve the water resistance of the material;The introduction of fibers increases the compressive strength of the material about 5-38%at the same bulk density.(3)Complete optimization of process parameters and material properties.Explore the effects of fly ash addition,treatment temperature and soaking time on the structure and properties of the materials.After treatment at 525? for 20 min,a lightweight insulation board with a bulk density of about 350 kg/m3,a compressive strength of 1.2 MPa,and a softening coefficient of 0.9 was obtained.(4)Complete cost analysis.The raw material cost is 360 yuan/m3,and the production cost is 10%of the raw material cost.Compared with the commercially available inorganic thermal insulation material,it has strong competitiveness.The raw materials for material preparation are widely used and the process is simple.The whole process is in the wet environment,there is no dust pollution,no harmful gas and solid waste,the composite material is friendly-environment and valuable.