| Multi-ribbed wall structure is a new seismic structural system with properties of lightweight and energy saving,heat preservation and sound isolation,green and environmental protection,construction with ease and low cost.Many researches have been implemented by now and some design computable methods guide to the engineering practice have been put forward.It is in great need to develop and study the properties of ecological lightweight cement-based wall materials with prevalence of the concept of "sustainable development" and the demand for the ecological architecture.It is important particularly to develop new energy-saving composite wall to suit local conditions and use local materials, which can promote the performance of multi-ribbed wall structures.Basic properties of lightweight infilled materials for multi-ribbed walls and mechanical performances of the new ecological walls,have been studied in details.The main work is as following:1.The changing law of B05 grade and B06 grade lightweight aerated concrete product have been researched such as compressive strength,split tensile strength,static elastic modulus, heat conduction coefficient,desiccation shrinking,varied with the water content.It has been ascertained that the equilibrium containing water quantity of lightweight aerated concrete product in service;at the same time,the changing rule of compressive strength under alternation between drying and wetting.Stress-strain curves of the lightweight aerated concrete product with normal service water content under uniaxial compression has been studied;based on the analysis of lightweight aerated concrete tensile strength and shearing strength,methods for determining the failure principles under multiaxial stress state and elasto-plastic constitutive equation have been deeply studied according to the unified strength theory.Systemic analysis of lightweight aerated concrete energy saving,flame retardancy, sound isolation,energy absorption,impermeability and environmental compatibility have been implemented according to the material characteristic.Combining familiar quality issues of lightweight aerated concrete in service,the laws of drying shrinkage of aerated concrete blocks are researched and modifying methods to solve the questions turns up in the service have been analyzed.2.Ecological lightweight foam concrete physical properties,technical indexes, specification standard and Stress-strain relationship under uniaxial compression have been studied.On this basis,the constitutive models of the ecological lightweight foam concrete have been studied according to the theory of continuum mechanics and fracture mechanics, respectively.At the same time,influencing factors have been analyzed and modifying methods have been put forward.3.Based on theory of tight density,particle size of smashed abandoned EPS packaging material has been optimized.After crushing,optimal regeneration of EPS the particle size and experiment,which meet the acquirement of tight density and cement encapsulating,many key factors effecting compressive strength,flexural strength and volume weight have been discussed such as quantity of EPS foam particle,number of surface modification agent and water / cement ratio.Optimal index are got under the condition of volume weight from 600Kg/m~3 to 1200Kg/m~3,relationship between compressive and volume weight are put based on the relative experiment.And the frost resistance experiment of regeneration EPS concrete to fit infilled material for multi-ribbed has been done.4.Some key facts on flexural strength,compressive strength and volume weight of wheat straw fiber,corn straw fiber cement-based composite materials are discussed such as the amount of wheat straw fiber or corn straw fiber,water/cement ratio,surface modification agent and so on.By orthogonal test the impact of different factors has been analyzed and the changing rule of flexural strength,compressive strength,and density by content of straw fiber obtained too.And the optimized combination of different inspection has been determined.5.Height-width ratio of ribbed beam and ribbed column which affecting the bearing strengthen and deform capacity of frame structures in high-performance concrete multi-ribbed walls have been studied;for the lightweight foam concrete product and lightweight aerated concrete product,multi-ribbed frame structure's bearing strengthen and deform capacity are also talked detailed;based on uniaxial compressive constitutive relations of the lightweight foam concrete product and lightweight aerated concrete product and adopted the William-Warnke five parameters principles,finite element analysis is computed and compared with the test results.6.In light of test on frame unit of multi-ribbed wall,the applicability of different calculation method and calculation model are discussed to frame unit of high-performance multi-ribbed wall based on researches on infilled frames.Also,mechanical performances and failure modes of the multi-ribbed wall are analyzed under different load cases by wall tests.To minimize calculation of elasto-plastic finite element analysis,regarded multi-ribbed wall as an unite structure,elasto-plastic finite element macro model of multi-ribbed wall are established,and its stiffness are determined according to hypothesis of small deformation and virtue work,especially decides the parameters of macro model.
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