Preparation And Properties Of Low Thermal Conductivity Insulation Foams Materials Based On Fly Ash

With the rapid development of urban and rural construction and the improvement of people's living standards,the insulation properties of thermal insulation materials have become increasingly demanding.Traditional organic insulation materials cannot meet the needs of modern building materials development because of flammability and other issues.Therefore,there is an urgent need to develop new energy-efficient building materials of good quality.Fly ash is a solid by-product of burning coal in a boiler.The use of fly ash to prepare foam insulation materials can meet the needs of recycling and energy saving and environmental protection at the same time,and comply with the needs of developing the times.In this dissertation,fly ash was used as the main raw material.The foamed insulation material with low thermal conductivity,low-density and certain compressive strength was prepared by adding expanded perlite/SiO₂ aerogel and graphite polystyrene particles?GEPS?.Specifically carried out the following work:?1?Based on analyzing the mineral composition of fly ash,a fly ash foamed inorganic insulation material was prepared by controlling the single factor variable method.The results show that when the water-cement ratio is 0.46,of the lithium carbonate coagulant is 0.45 wt%,of the foaming agent is 5 wt%,and of the foam stabilizer is 0.4 wt%,the inorganic fly ash foam insulation material The thermal conductivity is 0.66 W/?m·K?and the compressive strength reaches 1.16 MPa.Based on the experimental basis,the pilot test process and technical route for fly ash foam insulation materials were designed.The results of a pilot test in a company in Shandong Pingyuan showed that the bulk density was 350 kg/m³ and the thermal conductivity was 0.08 W/?m·K?.The compressive strength is 1.0 MPa,and the cost is about 172.01 yuan/m³.?2?To further improve the comprehensive properties of fly ash foaming inorganic insulation materials,an expanded perlite/SiO₂ aerogel composite filler was prepared and added to the fly ash foaming material.It was found that when the content of expanded perlite/SiO₂ aerogel was 20 wt%,the bulk density of the expanded perlite/SiO₂ aerogel changed fly ash foamed material was 335 kg/m3,and the compressive strength was 0.88 MPa.The thermal conductivity is 0.050 W/?m·K?.?3?To keep the low thermal conductivity of the fly ash foam insulation material,a graphite polystyrene?GEPS?fly ash thermal insulation composite material was prepared by further reducing the bulk density.The results showed the property of changed GEPS got was upgraded when the content of triethanolamine was 3vol%and the mass ratio of fly ash to GEPS was 4:1.75vol%of modified GEPS particles were added to the expanded perlite/SiO₂ aerogel fly ash foam insulation material,and the GEPS fly ash thermal insulation composite had a bulk density of 177 kg/m³,compressive strength of 0.47 MPa,and heat conduction.The coefficient is 0.054W/?m·K?.All three performance signals meet the needs of the industry standard JG158-2004.