Mechanism Research For Concrete Member Intensity Of New Low-alloy Coupled Steel Bars And Applied To Foundation Pit Engineering

Recently, with the development of economy and construction in our country, more and more which large scale projects going up. Many houses of large span, footage and deep foundation engineering are building, too. But, tradition materials aren't deal to these problems. We need to develop new materials and technology, in which supply structure and save money.At large, we make pre-stressed reinforcement and improve glue about to reinforcement with concrete. Coupled steel bars are also called modern strengthening reinforcement. In recent years, experimental research on different coupled steel bars concrete beams and plates are carried in many regions in china, however some zone make coupled steel bars by welding of ply, and it's process by point welding, we think that not really coupled steel bars in this paper. And at present coupled steel bars is made from cold-drawn wire or cold-rolled ribbed steel, make intensity improve, but plastic, ductility and welding capability drop, which can't be used in large structure with large reinforcement ratio, so limit technology of coupled steelbars.New low-alloy steel coupled steel bars is formed to ladder-framework by two parallel cold-drawn that's low-alloy steel are longitudinal reinforcement wedding with short and band cold-drawn that's low-carbon steel are transverse reinforcement in this paper. Study on its mechanical and technology properties. So, get suggestion model calculating formulas of crack width and rigidity are presented. And, suggestions apply to new specification-《Technical Specification For Concrete Member With New Low-alloy Steel Coupled Steel Bars》of Ji-lin province. The advantages of cooperating between coupled steel bars and concrete have been primarily accepted.First, this paper emphasizes on mechanics properties and technology capability of new low-alloy coupled steel bars for ready next to study on concrete structure. We finding:①That new low-alloy steel coupled steel bars more improve intensity than old. Resistintensity are 460 N/mm~2 .②For drop wedding wrong, we maketransverse reinforcement smaller than longitudinal reinforcement.③In order to good wedding, making carbon quantity drop a little.Second, we think new low-alloy coupled steel bars can rustproof all long. For save money, make it's size for 20 mm×90mm. And, we limited the smallest reinforcement quantity. Based on the capability of new low-alloy coupled steel bars, it still accords with work of common reinforced concrete structure. The calculation of strength can refer to current reinforced concrete standard. But the calculation of rigidity and cracking should differ from the common ones. So, get suggestion model calculating formulas of crack width and rigidity are presented, that's based on the capability of new low-alloy coupled steel bars. Third, through locale test data of anchor rod of soil stratum, prove it take advantage for anchor rod of soil stratum and rock.Last, making new low-alloy steel coupled steel bars in large span and footage floor. Which drop reinforcement's quantity and save money, in theory adopting new low-alloy steel coupled steel bars can improve bonding function between reinforcement and concrete and decrease width and space of cracks of bending member, which makes cracks, appear slight and dense.Applying new low-alloy steel coupled steel bars saves steel and concrete, not only apply to foundation work, consolidation of foundation pit, foundation beam, foundation mat, column, pile foundation, bracing of slope, anchor rod of soil stratum and rock, but also apply to irrigation works, road engineering, bridge engineering, etc.Now, the technology of coupled steel bars widely extends the using areas in china. The advantages of cooperating between coupled steel bars and concrete have been primarily accepted. As a result, many houses introduce coupled steel bars and gain economic benefits. The technology foundation of new low-alloy coupled steel bars is cold-drawn wire and low-carbon coupled steel bars. Surely, because of its property save a lot of resource and contribute for country.