钢套管再生混凝土加固钢筋混凝土柱偏压性能

为达到绿色建筑的目的,提出采用钢套管再生混凝土加固钢筋混凝土柱的思路,并完成1个未加固柱、3个加固柱的轴压试验以及8个加固柱的偏压试验.结果表明:采用钢套管再生混凝土加固后,试件偏压承载力及变形性能均有显著提高,各试件平均相对承载力提高倍数达1.12倍;再生粗骨料取代率对加固试件偏压承载力的影响不明显,而偏心较大时钢管中部截面应变随取代率的提高呈微弱增长;原柱初始应力的存在使得加固试件承载力峰值提前出现,且对其变形产生不利影响;偏心程度对加固试件的影响和普通钢管混凝土类似,随偏心距的增大,试件的承载力降低而钢管受压侧应变增大,且这种规律有随粗骨料取代率增加而增强的趋势.最后,通过对比国内外不同规范和学者提出的公式,采用EC4规范计算所得结果与钢套管再生混凝土加固柱偏压承载力试验结果吻合较好.

Behavior of Steel-jacket Retrofitted Column with Recycled Aggregate Concrete under Eccentric Loading

In order to achieve the goal of green building, the idea of steel-jacket retrofitted RC columns with recycled aggregate concrete was proposed. Tests of 1 original column, 3 retrofitted columns under axial compressive loading and 8 retrofitted columns under eccentric loading were conducted. It is found that after retrofitted by steel-jacket and recycled aggregate concrete, the bearing capacity and deformation performance of the RC column are significantly improved, where the relative bearing capacity is increased by 1.12 times on the average. The effect of recycled coarse aggregate replacement ratio on eccentric bearing capacity is not obvious, while the mid-span strain of steel-jacket increases slightly when the replacement ratio grows under large eccentricity. The peak loads of the retrofitted column with preload appear earlier, which shows a negative effect on deformation performance. Besides, the influence of the eccentricity is similar to that of the concrete-filled steel tubular column: as the eccentricity increases, the bearing capacity decreases and the compression-side strain of steel-jacket increases, and this trend becomes stronger when the replacement ratio increases. Finally, according to the comparison of design codes and the researches, eccentric bearing capacity calculated by EC4 is most consistent with the test results for this kind of retrofitted columns.