约束海砂再生混凝土柱轴压试验研究

Experimental study on axial compression of confined sea sand recycled concrete column

为研究约束海砂再生混凝土柱轴压试验的变形性能与破坏特征,分析了不同管材类型、再生粗骨料取代率与海砂氯离子浓度对其的影响。结果表明:玻璃纤维增强塑料(glass fiber reinforced plastics,GFRP)管约束海砂再生混凝土与钢管海砂再生混凝土破坏模式相近,但前者破坏较为突然;GFRP管约束海砂再生混凝土的破坏模式为管材纤维环向拉裂、核心混凝土压碎,而钢管海砂再生混凝土的破坏模式为钢管中部鼓曲、核心混凝土剪压破坏;因再生粗骨料取代率、海砂氯离子浓度的提高,GFRP管约束海砂再生混凝土与钢管海砂再生混凝土的峰值应力都会降低;再生粗骨料的取代率越高,GFRP管约束海砂再生混凝土与钢管海砂再生混凝土的峰值应变越大;不同约束管材条件下,试件承载力略有变化。最后,提出了针对GFRP管约束海砂再生混凝土和钢管海砂再生混凝土的轴压受力计算公式。

In order to study the deformation and failure characteristics of sea sand recycled concrete stub column under axial compression,this paper analyzed the influence of different pipe types,replacement rate of recycled coarse aggregate and chloride ion content of sea sand.The results show that the failure mode of glass fiber reinforced plastic(GFRP)tube confined sea sand recycled concrete is similar to that of sea sand recycled concrete filled steel tube,but the former is brittle.The failure mode of GFRP tube confined sea sand recycled concrete is fiber hoop cracking and core concrete crushing.However,the failure mode of recycled concrete with sea sand filled steel tube is middle drum bending and core concrete shear compression.Due to the increase of replacement rate of recycled coarse aggregate and chloride ion concentration of sea sand,the peak stress of GFRP tube confined sea sand recycled concrete and steel tube sea sand recycled concrete will decrease.The higher the replacement rate of recycled coarse aggregate is,the greater the peak strain of GFRP tube confined sea sand recycled concrete and steel tube recycled concrete will be.The bearing capacity of the specimen changes slightly under different restrained tube conditions.Finally,the calculation formulas of the axial compressive force of GFRP tube confined sea sand recycled concrete and steel tube recycled concrete are put forward.