椭圆形GFRP管高强混凝土短柱轴压力学性能试验研究

EXPERIMENTAL STUDY ON AXIAL COMPRESSION BEHAVIOR OF ELLIPTICAL HIGH-STRENGTH CONCRETE-FILLED GFRP TUBULAR STUB COLUMNS

为了调查椭圆形GFRP管高强混凝土短柱的轴压力学性能,验证Teng et al.2016模型(FRP约束椭圆形混凝土应力-应变关系模型)的适用性,通过4组8个椭圆形GFRP管高强混凝土短柱试件的单调轴压试验,来考察4种截面长短轴之比对其轴压力学性能的影响,并将试验结果与Teng et al.2016模型进行对比分析。试验结果表明:椭圆形试件的破坏模式均为椭圆形截面长轴顶点附近GFRP管发生环向断裂;椭圆形GFRP管的约束可显著提升核心混凝土的抗压强度与极限轴向应变,且抗压强度和极限轴向应变随截面长短轴之比的增大而降低;Teng et al.2016模型与本文试验结果吻合得较好,表明该模型对椭圆形GFRP管高强混凝土短柱试件依然适用。

In order to investigate the axial compressive behavior of elliptical high-strength concrete-filled GFRP tubular stub columns and verify the applicability of Teng et al.2016 model for the stress-strain relationship of FRP confined elliptical concrete,a total of four series of eight elliptical high-strength concrete-filled GFRP tubular stub column specimens were tested.One test parameter of the major axis-to-minor axis length ratio(abbreviated as aspect ratios),were considered in this experimental investigation.The test results revealed that the failure mode of elliptical specimens is the rupture of GFRP tube at around the apex of long axis of elliptical section.The confinement of elliptical GFRP tube can significantly improve the compressive strength and ultimate axial strain of concrete core,and the compressive strength and ultimate axial strain decrease with the increase of aspect ratios.The model of Teng et al.2016 is in good agreement with the test results of this paper,which indicates that the model can be used to predicate the behavior of elliptical high-strength concrete-filled GFRP tubular stub column specimens.