| Nowadays,with the increasing of the world's population,limited natural resources are being utilized continuously,and some resources are close to the limit of resource bearing.Environmental pollution is spreading rapidly and natural ecology is getting worse."Resource shortage and environmental degradation" restrict the sustainable development of Chinese society and economy.With the acceleration of urbanization,the urbanization process is accelerating,building energy consumption is soaring,and energy consumption is about 30 percent.Building energy consumption has become one of the three energy consuming industries in China,which greatly hinders the sustainable development of China's economic energy.Therefore,the development and use of energy-saving and environment-friendly materials will be an important way to reduce energy consumption.The main structural system for maintaining the internal temperature of the building is the external enclosure structure.At present,the exterior walls of buildings are mostly in the form of wall insulation.Additional organic insulation materials service life is far lower than the structure of life,they need regular replacement and the durability is poor,the fire resistance is poor.Once a fire is encountered,it burns quickly and releases toxic gases.The inorganic thermal insulation materials are mainly inorganic fiber insulation materials,such as rock mineral wool,etc.But it's too expensive and difficult to build,and there's a lot of dust and pollution in the process.Therefore,the environment-friendly self-insulation outer wall with strength and insulation performance will be a direction for the development of external wall insulation in the future.As well as improving the strength and temperature of the exterior wall,it also reduces energy consumption.Foamed concrete is a kind of lightweight concrete which has developed rapidly in recent years.The most prominent feature of foamed concrete is light and heat preservatioa But the current research on foam concrete is mostly confined to masonry products,roofing and inner walls,and the raw materials are limited to single input.According to the current building energy efficiency standards in China,combined with a large amount of industrial waste fly ash and agricultural waste straw fiber in northeast China,To add the powder ash and the straw fibers as a mixed mixture into the foam concrete,The fly ash can guarantee the later strength of the foam concrete and save the cement.The straw fiber can improve the cracking resistance of the foam concrete and postpone the development of the crack.From the green energy saving point of view,In order to ensure the performance of the foam concrete,the waste problem of fly ash and the environmental pollution caused by waste straw fiber are solved.Using foam concrete in the outer wall of the building,it can enhance the self-preservation of the structure,reduce the structure of the building,and reduce the impact of the earthquake.At present,the composite board in the market can be summarized into two types:steel-concrete composite slab and cement base sandwich board.The strength of the steel-concrete composite plate is high,but the thermal insulation performance is poor.The sandwich plate of cement base is surface layer with cement base material,and most of the core material is polystyrene and other plastic foam.This kind of combination edition has good thermal insulation performance,which is better than the steel-concrete composite plate,but the overall strength of the plate is weak,which is seldom used in the stressed member.If you replace the core of a concrete base with a concrete core,it will not only preserve the insulation of the wall,but also enhance the overall strength of the board,it also reduces the waste of environmental pollution caused by foam plastics.For this purpose,the combination type of cement base sandwich board is used.Based on the green light powder ash foam concrete,it's designed to make several new foam concrete panels.Through the production process and related experiments to study the performance of the new foam concrete composite board,such as the production process,light insulation and bearing capacity,etc.And then measure their availability and applicability in construction engineering,and related design advice is given The main work of this paper:(1)Production of light fly ash foam concrete composite board.Through a large number of experiments,the concrete test blocks with different fly ash,straw fiber and glass micro beads were produced.By comparing the compressive strength,and the dry density,the dry shrinkage of concrete,Finally,designed several groups of the test,it is concluded that the most suitable mixing ratio for the core material of the composite panels.(2)Design and production of the reinforced concrete-lightweight fly ash foamed concrete composite slab,and the bending test.Studying the characteristics and properties of various composite boards,derived the formula of flexural bearing capacity of composite slab,the cracking load of the composite slab is calculated and compared with the measured value,the reliability of the derivation formula is verified.The results showed that:without setting under the condition of shear connectors,cast-in-situ composite made of composite slab,the fly ash foamed concrete and ordinary concrete interface does not exist from the phenomenon,good integrity,able to work together;Compared with ordinary reinforced concrete slab,the bearing capacity of the composite plate is hardly lower,and the insulation performance is enhanced,and the self-weight is reduced effectively.(3)Using finite element analysis software ANSYS to analyze the nonlinear finite element of the composite board,comparing the simulation with the test value.It is concluded that the finite element software can help simulate the stress of this kind of composite slab.(4)Summarizing the physical and mechanical properties of the new foamed concrete composite board,give Suggestions and research prospects in respect of manufacturing process,design method and application of engineering. |
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