The Study Of Shear Property Of High-Strength Concrete Column Confined With High-Strength Continue Compound Spiral Hoop

In this paper, a new amendatory shear mechanism of beams and columns based on the 'truss+arch' mechanical model is put forward. The shear mechanism of general member of beam and column is analyzed and the theoretical and practical formulas of shear resistance about them are advanced. Making use of the former theory, the shear mechanism of the high-strength concrete column confined with the high-strength continue compound spiral hoop is analyzed taking account of the restriction that high-strength continue compound spiral hoops put on the high-strength concrete. And the theoretical formula of the column's shear resistance is put forward, and at the same time the statistical formula is also advanced based on the comparison with the value of test.Making use of the 'truss+arch' mechanical model, the range of the three shear failure models (shear-compression failure, diagonal-tension failure and arch-rib failure) is divided quantitatively, and the theoretical formula of shear resistance of beams and columns is educed. Making use of the theoretical formula of shear resistance, the shear mechanism of general beams is analyzed. The concrete strength of beam in the inclined compression zone is first made sure, the reducing coefficient' ' of beam's concrete in the inclined compression zone is putting forward. Make using of the critical point of the arch failure transiting to the tooth failure (which is also the point when the non-stirrup beam's shear bearing capacity arrives to its minimum) which is advanced in the arch-tooth theory of beams without shear reinforcement by G.Kani and the critical point of the diagonal-tension failure transiting to the shear-compression failure which is advanced in the anti-theory, the minimum shear resistance of general beams which is destroyed in the range of shear-compression failure is advanced. The minimum shear resistance of beams in the paper is close to the one in the Code for design of concrete structures 'GB50010-2002'.According to the actual project, the destroy of 448 kinds of beams are analyzed by computer by taking account of the effective coefficient ' ' of the strength ofconcrete confined by hoops, the relationship with the section property of beams, the critical point of the arch-rib failure transiting to the shear-compression failure which is advanced in the anti-theory, and the contribution to the beam's shear resistance of the concrete in the shear-compression zone. The maximum shear resistance of general beams, which is destroyed in the range of shear-compression failure in the paper, is little larger than the one in the Code for design of concrete structures 'GB50010-2002'. Finally, an applied formula of beam's shear resistance is advanced when the beam's shear failure model is the shear-compression failure. On the base of the anti-theory, the shear property of high-strength concrete column confined with high-strength continue compound spiral hoops is analyzed taking account of the advantage and disadvantage influence by the axial load. The detailing of the high-strength concrete column confined with high-strength continue compound spiral hoops and the applicability of the high-strength applied to the high-strength concrete is advanced first. The stress ' ce' and the strain ' cc' of the high-strength concrete confined with high-strength continue compound spiral hoops is advanced according to the test value and the theory in the document[60]. The influence on the shear resistance of columns by the axial loads includes two aspects: the one is that the axial load enhances the concrete strength of column in the inclined compression zone and the other is that the axial load increase the stress of the concrete of column in the inclined compression zone so that the shear resistance of column turns down. Taking account of the twoaspects, the concrete strength ' fc' in the inclined compression zone which contributes to the shear capacity of columns is put forward. Making use of the amendatory 'Truss+Arch' theory, the theoretical formula of the shear resistanc...