Study On Performance Analysis And Pore Structure Optimization Of Fly Ash Foamed Glass

Foam glass is a flame retardant porous lightweight thermal insulation material of Class A,its pore structure directly affects the thermal insulation performance of the material.However,the type and amount of admixture,raw material ratio,foaming temperature and time has a direct impact on the pores.In this paper,fly ash foam glass were prepared for using fly ash and glass powder as the main raw material,and adding appropriate amount of sodium carbonate,sodium phosphate,borax and other additives,and the mechanical properties of products,apparent density,pore size and thermal conductivity properties were determined and characterize its pore structure.Firstly,the effect of admixture types and dosages on fly ash foam glass physical properties,optimal dosage of admixture selection were investigated;Secondly,using orthogonal test method determines the best preparation process of foam glass;Finally,using ANSYS software analyses the influence on the thermal conductivity of foam glass in specimen porosity,pore size and thickness.Specific research content and test results are as follows:(1)Using single factor test to study foam glass in different dosage of additives effect on the properties.The results showed that with the increase of dosage of sodium phosphate as the foam agent,the apparent density and thermal conductivity decreased,the porosity increased,sample aperture in the range of 1 to3mm the distribution is relatively uniform,the average pore size is 1.1mm;considering the performance index of foam glass,its content is 4%,the foam glass samples are prepared by the ideal performance.(2)By single factor test of sodium carbonate to study different amount influence on the properties of foam glass.The results showed that with the increase of sodium carbonate,the density,thermal conductivity and mechanical strength decreased;gas bubble phenomenon is especially obvious,leading to porosity increased and the number of connected holes Increased;when sodium carbonate content is 5%,thermal conductivity is 0.0735W/(m·K),compressive strength is 1.58MPa,flexural strength is 0.75MPa,and density table is 0.276g/cm~3.(3)Adopting orthogonal test to study the amount of fly ash,sodium carbonate dosage,foaming temperature and time four factors on performance of fly ash foamed glass.the results show that the maximum influence on the compressive strength of specimen,porosity and thermal conductivity is the dosage of fly ash,content of sodium carbonate on the compressive strength with minimal impact;considering the range analysis and variance analysis,the reduction of energy consumption and the cost of firing,selected the best test plan preparation of fly ash foam glass:fly ash is 25%,sodium carbonate dosage is 4%,foaming temperature is 850?and foaming time is 20min.(4)Using ANSYS finite element analysis software to simulate and analyze the foam glass samples in thickness and pore porosity and thermal conductivity,the results show that when the porosity is a certain value,the thermal conductivity of foam glass in general decreases and different porosity changes are different;when thickness of the sample is a certain value,as the porosity increased,the heat resistance of foam glass specimen increased and its insulation properties increased gradually;pore distribution of foam glass is more uniform and arranges more neatly,the greater the thermal resistance of the material,the heat preservation performance is better.