方钢管超高强钢纤维混凝土柱轴压性能研究

Axial Compressive Behavior of Ultra-high-Strength Steel Fiber-Reinforced Concrete-Filled Square Steel Columns

关键词:  钢管混凝土柱  超高强混凝土  钢纤维混凝土  轴压性能  延性

Key words:  concrete-filled steel column  ultra-high-strength concrete  steel fiber-reinforced concrete  axial compressive behavior  ductility

摘要:

为研究方钢管超高强钢纤维混凝土柱的受压性能，开展了12个方钢管超高强钢纤维混凝土柱的轴压试验，试验参数包括钢管屈服强度与厚度、混凝土基体强度和钢纤维掺量.结果表明：掺入钢纤维基本不改变试件的破坏形态；对于混凝土棱柱体抗压强度介于80~150 MPa之间、套箍指标介于0.33~1.43之间的方钢管钢纤维混凝土柱，其管内混凝土的抗压强度与对应混凝土棱柱体抗压强度接近；钢纤维对延性的提升作用随着混凝土强度的提高和套箍指标的增大而降低；当混凝土棱柱体抗压强度为130 MPa、套箍指标为0.90时，掺入1.5%的钢纤维对提升方钢管混凝土柱的延性不起作用.

Abstract:

To study the compressive behavior of ultra-high-strength concrete-filled square steel columns， 12 square steel columns filled with ultra-high-strength steel fiber-reinforced concrete were tested under axial compression. The test variables included the yield strength and thickness of the steel column， the strength of the matrix concrete and the content of steel fiber. The results indicate that the addition of steel fiber doesn't change the failure modes of the specimens. For the columns with the concrete compressive strength between 80 MPa and 150 MPa and the confinement index between 0.33 and 1.43， the compressive strength of the concrete in the steel square is close to that of the corresponding unconfined concrete. The effect of the steel fiber on improving the ductility of square concrete-filled steel columns decreases as the concrete strength and confinement index increases. When the concrete compressive strength is 130 MPa and the confinement index is 0.90， the addition of steel fiber with 1.5% volume content ratio has no effect on improving the ductility of square concrete-filled steel columns.