Experimental Study On Non-autoclaved Lightweight Porous Concrete For Partition Wall Board

Prefabricated buildings is actively promoted in China,"The central committee of the communist party of China on the management of the state council on further strengthening the construction of urban planning several opinions(found [2016] no.6)pointed out that China aims to increase the proportion of prefabricated buildings in new buildings from about 5 percent to 30 percent within 10 years.Since the partition board does not involve the structural load bearing,it is a relatively easy to realize the assembled component,which is the main component type developed actively in recent years.According to "Standard for assessment of prefabricated building"(GB/T 51129-2017),the minimum application proportion of prefabricated internal partition is 50%,and the market demand increment of partition board is predicted to be 1.02 billion square meters.At present,the main product of precast partition board in China is autoclaved ceramsite concrete wallboard,but its production needs autoclaved curing,limited by environmental problems,it is difficult to expand the output on a large scale.In addition,the production of autoclaved ceramsite concrete wallboard also faces the problem of shortage of river sand and unstable quality of ceramsite.In order to promote the development of prefabricated buildings,it is urgent to develop new products of non-autoclaved partition panels.In view of the above problems,based on the optimized design of the hole shape of the partition panel,this study systematically studies the raw materials,proportion and curing system of lightweight porous concrete and the wall panel specimens that meet the "General technical requirements of light weight panel used for building partition"(JG/T 169-2016)were obtained,The specific research contents and main conclusions are as follows:1.Contrast analysis of the rounded square hole and round hole two opening ways on the properties of partition panel with concrete requirements,proposed from preparation of autoclaved clapboard necessary condition:Lightweight porous concrete density ?1745kg/m3,compressive strength ?7.5MPa.Compared with the round hole partition wall board specimen,the partition board specimen with the rounded square hole in equals the surface density,higher strength.The preparation of non-autoclaved partition wall is more suitable for retaining rounded square hole.2.The process of preparing lightweight porous concrete by stirring gas is simpler than that of pre-foaming method,and the strength of wall plate specimen prepared by light porous concrete prepared by stirring gas also has certain advantages,which is more suitable for use in production.3.Using ceramsite and river sand as aggregate,the optimal mix ratio is: water-cement ratio 0.30,rubber-sand ratio 1:2.0,the absolute volume content of ceramsite is 15%.For curing system: static 5 h after forming,then 50 ? dry curing mold release after 5 h,the natural curing to 3 d age.4.Using ceramsite and recycled total-fine aggregate as aggregate,the optimal mix ratio is: water-cement ratio 0.30,rubber-sand ratio 1:2.0,the absolute volume content of ceramsite is 15%.For curing system: static 5 h after forming,then 50 ? dry curing mold release after 5 h,the natural curing to 7 d age.5.Using recycled total-fine aggregate as aggregate,the optimal mix ratio is: watercement ratio 0.28,rubber-sand ratio 1:2.2.For curing system: static 5 h after forming,then 50 ? dry curing mold release after 5 h,the natural curing to 10 d age.6.The curing cost of non-autoclaving is 8.4% lower than that of autoclaving.There are significant economic advantages in using fully recycled fine aggregate to prepare nonautoclaved partition wall board,and the total cost of curing and material is as low as 59% of the original cost.