Study On The Influence Of Composite Insulation Lightweight Aggregates Foam Concrete Performance

Expanded polystyrene(EPS)foam concrete is a new type of green thermal insulation building material with light weight and good thermal insulation performance.The research on EPS foam concrete is mainly in the foam content,EPS content and water-cement ratio.Little research has been done on the mixing of lightweight aggregate and EPS to produce foam concrete.EPS foam concrete has the disadvantages of low compressive strength and flammability.In order to change the above shortcomings,we mixed expanded perlite,hollow glass beads and EPS to make a new type of foam concrete,and carried out relevant tests.The microscopic study of composite foam concrete was conducted by SEM,laser microscope and XRD.The main study conclusions were obtained as follows.(1)Firstly,the expanded perlite and expanded polystyrene particles were mixed to make composite EPS foam concrete.After curing,we tested the dry density,compressive strength,thermal conductivity,water absorption,moisture content,porosity and combustion mass loss rate of composite EPS concrete.The results show that the proper addition of expanded perlite increases the dry density of EPS foam concrete and makes the bulk density larger.The compressive strength of composite EPS foam concrete is improved to a certain extent by adding expanded perlite,with the maximum increase of 175.5%,reaching 1.66 MPa.The thermal conductivity of EPS foam concrete is greatly reduced by adding expanded perlite,and its thermal insulation performance is improved.The maximum reduction is 7.3%,reaching 0.1235W/(m · K).To some extent,expanded perlite increases the water absorption and moisture content of EPS foam concrete.The combustion mass loss rate of composite EPS concrete is reduced.The maximum reduction is 67.4%,reaching 4.2%.(2)In the second step,hollow glass beads and polystyrene particles were mixed to make composite EPS foam concrete.The above properties of composite EPS foam concrete were tested.The results show that the dry density of EPS foam concrete is increased and the bulk density is increased by adding hollow glass beads.The compressive strength of composite foam concrete has been greatly improved by adding hollow glass beads,with a maximum increase of 291.1%,reaching 2.03 MPa.The thermal conductivity of EPS foam concrete is reduced by adding hollow glass beads,with a maximum reduction of 3.15%,reaching 0.1291W/(m · K).Adding hollow glass beads in EPS foam concrete greatly reduces the water absorption and moisture content of EPS foam concrete.And the combustion mass loss rate is reduced to a certain extent,with a maximum reduction of63.5% to 5.68%.(3)The third step was to select the best mix proportion based on the above test data by the efficiency coefficient method,and then made the triple mixed composite foam concrete based on this ratio.The above properties of composite EPS foam concrete were tested.The results show that the dry density of concrete mixed with three kinds of lightweight aggregate is reduced,and the maximum reduction is 27.8%,reaching 0.09W/(m · K).The water absorption and moisture content of EPS foam concrete change little.The combustion mass loss rate of concrete mixed with three kinds of lightweight aggregate is reduced to a certain extent,with a maximum reduction of 29.8% to2.23%.The performance of composite foam concrete with three kinds of lightweight thermal insulation aggregates is better than that with one or two kinds of aggregates.