The Preparation And Performance Optimization Of Fly Foam Glass

In this paper, regarding the fly ash and the waste glass as the main raw material, adding kinds ofadmixtures such as foaming agent, flux agent and foam stabilizing agent etc, the fly ash foam glass exteriorwall insulation materials were prepared under specific firing process and the physical properties of productswere measured such as strength, apparent density, porosity, water absorption, coefficient of thermalconductivity. The initial exploration experiment shows that the main four factors influencing the physicalproperties of fly-ash foam are foaming agents’ type, dosage, fly ash content, foaming temperature andfoaming time. Aiming at the four factors above, the single factor experiment was carried out, based onwhich the optimization of orthogonal experiment have been done. The result of the experiment shows that:(1)With the increasing of the content of foaming agent, the generated gas and the porosity of thematerial are following increased while the apparent density, the compressive strength, the flexural strength,the water absorption and the thermal conductivity are following reduced. Considering the physicalperformance of each material, we used the sodium carbonate as foaming agent, the content of which beingappropriate range from2%to4%, thus the apparent density and the coefficient of thermal conductivity ofthe material could respectively be lower than0.4g/cm3and0.07W/(m K).(2)The dosage of fly ash has a great impact on the preparation and performance of fly-ash foamedglass. With the increasing of the dosage of fly-ash, the soften temperature of the material rise up against themolten softening of the glass powder, while the porosity of material decrease, the apparent density increaseand the coefficient of thermal conductivity of materials obvious increase. It will seriously affect the qualityof material. And its energy consumption is excessive. Therefore the dosage of fly ash should below25%.(3)The foaming temperature has a relatively smaller impact on the apparent density and the porosity ofmaterial, despite the other properties are unstable. It means that the foaming temperature has a greatinfluence on the pore structure of the material. The high temperature will lead to the connection of pores inthe material and the appearance of open pores. The strength, water absorption and coefficient of thermalconductivity of the material corresponding to the increasing number of open pore have great differences.(4)With the extension of foaming time, the pore wall of material gets thinner, the pore size gets biggerand the porosity has a raising trend. When the foaming time exceeds40minutes, the pore diametersignificantly increases, and there’s a large number of connected hole appear. It leads to the physicalproperties of the material reducing. Therefore the appropriate foaming time should be controlled between20to40minutes.(5)The study of the factors affect the physical properties of the fly-ash foamed glass through theorthogonal experiment shows that the dosage of the fly ash has the greatest average impact on everyphysical index and that the foaming agent has a greater impact on coefficient of thermal conductivity andbibulous rate of the material. The thermal conductivity of the fly-ash foamed glass made through the besttest preparation parameters of the optimized orthogonal experiment can reach to a minimum level of0.0566W/(m K), and the apparent density can reach to a minimum level of0.222kg/cm3. It makes the materialpossess good performance of heat preservation and heat insulation.