| The steel-concrete composite bridge after the steel bridge and the reinforced concrete bridge is accepted by the engineering field, and is quickly developing of bridge structure form. Composite beam can well develop the mechanics characteristic of steel material and concrete, and have construction convenience, significant general benefits, is important development one of the directions of bridge engineering and applying foreground vast.Steel-lightweight aggregate concrete composite structure has been developed as a kind of new composite structure based on the steel-concrete composite structure and lightweight aggregate concrete structure. The steel-lightweight aggregate concrete composite beam has a saving steel, section reasonable, section height small, better member stability, ductility good, economy etc.. Steel-light bone's anticipating a concrete combination structure be the foundation which combines structure and light bone to anticipate concrete structure in the steel-concrete up develop of a kind of new combination structure. The steel-lightweight aggregate concrete composite beam has an economy steel material and section reasonable, lightening structure weight, better member stability, ductility good, economy good, increasing structure span or story high, lower foundation processing expenses, acquiring better economic benefit and social benefit Using a lightweight aggregate to replace a natural aggregate concrete batching in the meantime, can reduce the depletion of resources to natural aggregate, and realize the construction targets of environmental protection and sustainable development. The steel-lightweight concrete composite structure is suitable development for the building higher and higher, and the span larger and larger. Therefore, the steel-light aggregate concrete composite structure is a kind of ideal structure system and has a good development foreground.Experiment research and theories analytical enunciation, the steel-lightweight aggregate concrete composite beam is a kind structure form of safety, efficiently, economy and construction convenient, and applicable to large span bridge structures and multi-storey building structures. The steel-lightweight aggregate concrete composite beam in comparison with steel beam can save to invest 10-40%.Compared with the reinforced concrete beam composite beam, the beam has light weight, section height small, better the anti-vibration performance and quick construction. The steel-lightweight aggregate concrete composite beam has very strong competition ability in the long-span bridge construction, market foreground vast. Knowing to all, the north is in the cold region, construction the work period is shorter, the steel-lightweight aggregate concrete composite beam has quick construction and lower to construction the machine requirement, for speeding up highway, railroad construction and building construction have important meaning.The steel-lightweight aggregate concrete composite beam research only is in beginning stage in the domestic, the local Northeast University, Shenyang Jianzhu University etc. did some foundation work and established for aftertime's research bases of theory and experiment. In fundamental research, theoretical storage and creative structure system etc. of the steel-lightweight aggregate concrete composite beam still have a margin with international level in our country. And for that realm, domestic and international development are still very insufficiency. This item will do the thorough research of mechanics behavior and work performance, calculating theory and design analyzing method of the establishment and expanding its application range. The study results may push and carry out bridge structure, construct structure...etc. to long-span, big space, heavy carry a direction development, simplification construction work preface with lower engineering price, have bigger theoretical meaning, applied foreground and considerable economic benefit. In the meantime, it can also push a big development of lightweight aggregate building material. This is exact selection original intention for the steel-lightweight aggregate concrete composite beam bridge to carry on thorough theoretical analysis, calculation and experiment research. Along with the quick development of economic construction, amount of steel-lightweight aggregate concrete composite structure buildings will continuously increase, but currently our country still have not a set of calculation theory and design method, opening the steel-lightweight aggregate concrete composite beam bridge research work is very necessary.The steel-lightweight aggregate concrete composite beam bridge bending performance and mechanics behavior are discussed in the text, mainly opened a following several research works:1. According to the elastic theory, adopting energy variational principle method analyzed the effective width of flange slab for the steel-lightweight aggregate concrete composite beam, respectively deduced the computing formula for the effective width of the concrete flange slab, which were to take no account of slip influence and considering slip influence, studied the distributed regulation of flange slab effective width along the beam span direction, provided a basis for the elastic theory analysis of the steel-lightweight aggregate concrete composite beam.2. Established a steel-lightweight aggregate concrete composite beam slippery model using the elastic theory analysis method, deduced flexivity and slippery control the differential equation to consider the interface slippery effect influence of the lightweight aggregate concrete composite beam. The text got flexural equations and interface slippery analytic equations of the lightweight aggregate concrete composite beam to consider the interface slippery effect influence. Considered slippery effect influence, curvature and moment of the lightweight aggregate concrete composite beam were not the relation of elementary beam theories, but increased additional moment. The text deduced the additional moment equations to consider slippery effect. Using the additional moment equations, can expediently adopt the calculation formula of the material mechanics to calculate flexivity to consider slippery influence of the composite beam3. Established a mechanical model calculated stud, adopting according to the analytical method of measured stud transformation put on stud analyzed transformation and load carrying capacity of stud, studied the influence stud load carrying capacity factor in lightweight aggregate concrete, and gave the relationship between load and slippage of stud in lightweight aggregate concrete composite beam, computed a result and actually measured result fitted together better.4. Analyzed the influence factor of stud shearing load carrying capacity, carried on comparison of the computing stud shearing load carrying capacity and actually measured value, result showing, the current criterion computed formula of stud shearing load carrying capacity can directly used for design of the lightweight aggregate concrete composite beam in our country, criterion computing value with push out test value are more close, and to be partial to at the safety.5. Analyzed influence factor of bending load carrying capacity for the steel-lightweight aggregate concrete simply supported composite beam, pointed out to adopt a current criterion calculated bending load carrying capacity for the steel-lightweight concrete simply supported composite beam, particularly the bending load carrying capacity calculating value at regular service ultimate limit state is too big and the structure is partial to at the insecurity. There is necessity to make a further research to calculating additional bending load carrying capacity lower value to consider slip influence for the steel-lightweight aggregate concrete composite beam.6. Analyzed influence factor of deflection for steel-lightweight aggregate concrete simply supported composite beam, pointed out to adopt lowered rigidity method calculated deflection of the current criterion for the steel-lightweight concrete simply supported composite beam at regular service ultimate limit state is too small and the structure is partial to at the insecurity.7. Carried on 10 stud to push out test in the lightweight aggregate concrete and analyzed the interface slippage effect of the steel-lightweight aggregate concrete composite beam, introduced a few kinds typical load slippage curve of stud, gave the load slippage curve of stud suitable for the steel-lightweight aggregate concrete composite beam.8.Carried on 2 load carry experiment of the steel-lightweight aggregate concrete simply supported composite beam, at two point symmetrical concentration loading, studied on shearing slippage between the steel beam and lightweight aggregate concrete flange slab, shear lag effects of the concrete flange slab and strain variational regulation, got some worthy conclusions. |
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