轻质超高性能混凝土长柱轴心受压试验

Axial Compression Test of Lightweight Ultra-High Performance Concrete Long Column

针对轻质超高性能混凝土(LUHPC)长柱失稳问题,开展了轻质超高性能混凝土长柱轴心受压试验.设计制作了长细比为6~22的10根LUHPC长柱和10根高强混凝土长柱试件,对比分析了不同长细比对LUHPC长柱承载力、荷载-应变和荷载-挠度等影响,明确了其破坏形态,获得了长细比6~22的LUHPC长柱稳定系数,建立了LUHPC长柱的稳定系数计算修正公式.试验表明:随着长细比的增大,LUHPC长柱和高强混凝土长柱承载能力均逐渐减小,稳定系数也均逐渐减小,LUHPC柱长细比从6~22的稳定系数为1~0.73,稳定系数计算值与试验值吻合较好;LUHPC长柱破坏机理是钢筋先屈服,然后混凝土达到应变峰值,试件发生破坏.

To solve the instability problem of long columns of lightweight ultra-high performance concrete(LUHPC),the axial compression test of long columns of lightweight ultra-high performance concrete was carried out.Ten LUHPC long columns and ten high-strength concrete long columns with slenderness ratio of 6~22 were designed and manufactured.The effects of different slenderness ratios on the bearing capacity,load-strain and load-deflection of LUHPC long columns were comparatively analyzed,and the failure modes were defined.The stability coefficients of LUHPC long columns with slenderness ratio of 6~22 were obtained,and the revised formula for calculating the stability coefficients of LUHPC long columns was established.The test results show that with the increase of slenderness ratio,the bearing capacity and stability coefficient of LUHPC long columns and high-strength concrete long columns decrease gradually.The stability coefficient of LUHPC column with slenderness ratio from 6 to 22 is 1 to 0.73,and the calculated value of stability coefficient is in good agreement with the experimental value.The failure mechanism of LUHPC long columns is that the steel bars yield first,then the concrete reaches the peak strain,and the specimens are destroyed.