Study On Production Technology And Performance Of Autoclaved Aerated Concrete Exterior Wall Slabs For Fabricated Building

Autoclaved aerated concrete is widely used in construction projects due to its light weight,heat preservation and sound insulation.However,most of the products of autoclaved aerated concrete in China are mainly blocks,which are limited in application and single in product type,and cannot show all the advantages of autoclaved aerated concrete.With the full implementation of the policy of developing fabricated building in China,autoclaved aerated concrete slab,as the ideal wall material of fabricated building,will surely become a new direction for the development of autoclaved aerated concrete products,thus leading the overall upgrading of autoclaved aerated concrete industry.At present,autoclaved aerated concrete slabs are rarely used in exterior walls of fabricated building,and there are fewer enterprises that can produce aerated concrete exterior wall slabs.The research on their production technology and product performance is still in the initial stage.In this paper,the B05 sand-cement-quicklime system autoclaved aerated concrete exterior wall slabs for fabricated building is taken as the research object.Firstly,in the laboratory,the basic properties of autoclaved aerated concrete material are studied by changing the kinds and content of raw materials.Then,through the mechanical and thermal tests of the autoclaved aerated concrete exterior wall slabs for fabricated building produced by the factories,the performance of these slabs in application is studied.Finally,through tracing the production process parameters and product testing,the influence of production process on the performance of autoclaved aerated concrete exterior wall slabs for fabricated building is studied,and the key control points of production technology are summarized,and the quality retrospective system of autoclaved aerated concrete exterior wall slabs for fabricated building is put forward.The results show that the higher the content of SiO₂ in siliceous materials,the higher the compressive strength of autoclaved aerated concrete;The compressive strength of autoclaved aerated concrete is the highest when the content of quicklime is 17%;Synergist can improve the fluidity of autoclaved aerated concrete slurry and the compressive strength ratio of products;Styrene acrylic emulsion can reduce the tensile modulus and shrinkage of autoclaved aerated concrete,and improve the frost resistance of autoclaved aerated concrete.The B05 autoclaved aerated concrete exterior wall slabs for fabricated building can meet the requirement of flexural bearing capacity under three reinforcement forms;The heat transfer coefficient of sandwich plate is the lowest among the three types of composite plate,which is0.28 W/?m2·k?.In the production of B05 autoclaved aerated concrete exterior wall slabs for fabricated building factory,the higher the speed of mixer,the higher the compressive strength of products;Horizontal pouring can improve the bond strength of steel bar;When the constant temperature time is 7 h,the product has the highest compressive strength;When the content of magnesite is 2.0%-3.0%,the cracking phenomenon of the slabs during steam curing can be reduced.The addition of quicklime can affect the casting stability of green body and the floatation of reinforcing bar;The optimum mix ratio for production are cementitious material34%³5%,water-material ratio 0.60⁰.61,aluminium powder content 10/10,000¹1/10,000,pouring temperature 40?;The quality fluctuation can be reduced by using the quality backtracking system proposed in this study.