对混凝土柱静态破碎效果的分析

Analysis of static crushing effect of concrete column

摘要:

为考察混凝土强度及是否割断箍筋对柱静态破碎效果的影响,对不同强度等级的8个混凝土柱在柱顶沿柱高钻孔并注入静态破碎剂浆体,其中4个试件在孔侧面割断箍筋,使用裂缝的平均宽度之和表示试件的破碎效果。试验结果表明:试件的破碎效果随着混凝土强度的提高而降低,不割断箍筋的试件,破碎效果的降低幅度逐渐增大,割断箍筋的试件,破碎效果的降低幅度逐渐减小；当柱截面、配筋、成孔、静态破碎剂浆体的注入等都相同的情况下,割断箍筋能有效提高静态破碎效果,但随着混凝土强度的提高,割断箍筋对破碎效果的提升程度逐渐降低；不割断箍筋的试件,裂缝分布密集,静态破碎过程中没有块体脱落,但去除保护层后,试件内部酥碎；割断箍筋的试件,在静态破碎过程中柱角部会有块体脱落。

Abstract:

In order to investigate the impact of concrete strength and whether the stirrups are cut off on the static crushing effect of columns, eight concrete columns with different strength grades were drilled at the top of the columns along the column height and injected with static crushing agent slurry, and the stirrups were cut off at the side of the holes for four specimens. The sum of the average width of the cracks was used to indicate the crushing effect of the specimens. Test results show that the crushing effect of the specimens decreased with the increase in concrete strength. For the specimens without cutting off stirrups, the decreasing range of the static crushing effect increased with the increase in concrete strength. For the specimens with the stirrups cut off, the decreasing range of the static crushing effect decreased with the increase in concrete strength. Under the conditions that the column section, reinforcement, pore-forming, and static crushing agent slurry injection were all the same, cutting off stirrups could effectively improve the static crushing effect. However, with the increase in concrete strength, the impact of cutting off stirrups on the improvement of the crushing effect decreased gradually. Specimens without cutting off stirrups had densely distributed cracks, and no blocks fell off during the static crushing process, while after removing the protective layer, the inside of the specimens was crumbly; for the specimens with the stirrups cut off, blocks fell off at the corners of the column during the static crushing process.