Study On Properties Of C100 Concrete Pressure Cylinder Axis Of 500MPa Spiral Stirrups

With the development of social economy, in order to meet the requirements of building materials and saving land, super-high strength is widely used in building materials in structures has become inevitable. In general, concrete is a brittle material that is easy to crack, and with high strengthened concrete, its brittleness features is the more obvious, local fracture displacement tends to rapid development, structural ductility is reduced, makes the security of engineering structure with seismic requirements. This research puts forward with high strength and high modulus PVA fiber ultra-high strength concrete column under the high-strength stirrup restraint, not just provide higher axial compression resistance, and have resistance to brittle failure and consume the earthquake energy toughness performance, meet the requirements of sustainability in civil engineering、economy, at the same time can make structures more light and delicate appearance.The purpose of this article is based on the existing constitutive model of confined concrete, join this variable to correction model, dosage of fiber formation can be applied to fibers and stirrups common constraint concrete constitutive model, thus to build more than 100 MPa grade concrete strength, stirrup strength level is above 1000 MPa tall and big span structure the basic mechanics model of bearing components required to provide theoretical basis and experimental basis.In this paper, through summarizing the research achievements of scholars at home and abroad is expounded, the root of 16, 500 MPa level stirrup restraint C100 concrete columns of monotonic axial compression test, the high strength concrete constitutive model with constraints is analyzed. Results indicate that the ratio of longitudinal reinforcement and depth, fiber content, size effect and stirrup reinforcement types have a certain effect on confined concrete stress-strain curve. The greater the ratio of longitudinal reinforcement and depth of specimen column, the greater the peak stress of confined concrete, the greater the ductility performance improved obviously. The greater the fiber content, the greater the confined concrete ductility performance improved obviously, the right amount of fiber content can improve the peak stress of confined concrete, too much will reduce the peak stress, with the increase of fiber content, peak stress of confined concrete is showed a trend of lower. the greater the specimen size, the smaller the increase of the peak stress, large size specimen need more constraints, and small size specimen fluctuate less stress and the strain value change. Relative to use light round steel bar, stirrup using an equivalent reinforced bar, more can improve the strength and ductility of confined concrete. So the reasonable ratio of longitudinal reinforcement and depth, fiber content and type of stirrup reinforcement is significant to improve the ductility of the member. Based on the test results of three typical stress-strain constitutive model of confined concrete are analyzed, and on the basis of Legeron model, put forward the suitable for this paper the results of stress and strain of confined concrete constitutive model, the prediction curve with the test data can better meet.