UHPC加固混凝土柱轴压承载力试验研究

Experimental Study on Axial Compressive Bearing Capacity of UHPC Reinforced Concrete Columns

摘要:

为研究普通钢筋混凝土柱采用超高性能混凝土（Ultra High Performance Concrete，UHPC）加固后轴压承载力的变化情况，设计、制作了2根试验柱（未加固混凝土柱RC和UHPC加固柱UC），分析加固前后试件的荷载-位移曲线、承载力变化规律及破坏模式。结果表明，UC试件相较于RC试件刚度和承载力大幅提高，其中承载力增幅高达208%；通过代入不同规范UHPC加固柱轴心抗压承载力计算方法，并结合试验数据，确定了精度较高且安全可靠的计算公式；依托实际工程，设计了50mm厚UHPC桥墩加固方案，较原桥墩承载力提升了67%；相同承载力提升幅度下，加固层厚度较常规混凝土减小58%。

Abstract:

To study the variation of axial compressive bearing capacity of ordinary reinforced concrete columns reinforced with ultra-high performance concrete (UHPC), two test columns (unreinforced concrete column RC and UHPC reinforced column UC) are designed and fabricated to analyze the load-displacement curve, bearing capacity change rule and failure mode of specimens before and after the reinforcement. The result shows that compared with RC specimens, the stiffness and bearing capacity of UC specimens are significantly improved, in which the range of bearing capacity increases up to 208%. By substituting into the different calculation methods for the axial compressive bearing capacity of UHPC reinforced columns and combining with the test data, a high-precision, safe and reliable calculation formula has been determined. Relying on the practical projects, a reinforcement scheme for a 50mm thick UHPC bridge pier is designed to increase the load-bearing capacity of the bridge piers by 67% compared with the original ones. Under the same increase in bearing capacity, the thickness of the reinforced layer is reduced by 58% compared with that of conventional concrete.