论文部分内容阅读
这项试验主要借助新型活性约束技术研究约束混凝土的单轴压缩性能。采用热触发的预应变形状记忆合金(SMA)螺线恢复应力来施加混凝土圆柱试块主动侧限压力。首先,利用热力试验确定选用的螺线恢复应力和预应变损失。其次,单独利用SMA螺线或与玻璃纤维增强复合材料(GFRP)共同约束混凝土柱块。对约束混凝土柱块进行压缩试验,比较它和仅用GFRP被动约束柱块性能的不同。结果表明,SMA螺线在单调及反复加载下具有稳定的恢复应力。试验中测到的预应变损失很少,因此,它对约束混凝土的受力没有影响。试验结果表明,SMA螺线对混凝土试块上主动侧限压力大及稳定的情况是有效的。此外,相比GFRP被动约束混凝土柱块,SMA螺线的极限应变得到明显提高,而强度只是略有提高。
This experiment mainly studies the uniaxial compressive behavior of confined concrete by means of a new type of activity restraint technique. Thermally activated pre-strained shape memory alloy (SMA) helical recovery stress was applied to the active cylindrical confinement test block. First, thermodynamic tests are used to determine the spiral recovery stress and pre-strain loss. Second, the use of SMA spiral alone or in combination with glass fiber reinforced plastic (GFRP) to constrain concrete blocks. Compression test was carried out on the confined concrete column to compare the performance of the confined concrete column with that of GFRP. The results show that the SMA spiral has a stable recovery stress under monotonous and repeated loadings. The prestrain loss measured in the experiment is small, so it has no effect on the force of the confined concrete. The experimental results show that the SMA spiral is effective for large and stable active side pressure on concrete specimens. In addition, compared with GFRP passively confined concrete columns, the SMA helix has a significant increase in ultimate strain and a slight increase in strength.