钢管活性粉末混凝土轴压短柱受力性能试验研究

进行22根钢管活性粉末混凝土(钢管RPC)轴压短柱试验,分析其荷载-变形曲线、破坏特征和影响极限承载力的主要因素。试验研究表明:钢管RPC轴压短柱的荷载-纵向应变曲线弹性阶段约为极限荷载的90％~95％;套箍系数ξ较小时,在达到极限荷载后承载力急剧下降;ξ较大时,在达到极限荷载后承载力下降平缓并呈回升趋势。ξ较小的试件多呈剪切破坏形态;ξ较大的试件所有断面上均被墩粗,试件的上、下两端明显局部鼓曲。构件承载力随RPC强度fc的提高而提高,两者基本成线性关系;套箍系数ξ越大,构件承载力也越大,但钢管对RPC的约束效果比对普通混凝土的差。提出的钢管RPC轴压短柱极限承载力的实用计算公式计算出的结果与试验结果吻合良好。

Experimental study of behavior on RPC filled steel tubular stub columns under axial compression

Experiments of 22 RPC filled the steel tubular stub columns subjected to axial compression are carried out. The load versus displacement curves, the failure patterns and the influences of the confinement factor ?and the strength of RPC fc on the ultimate loading capacity have been discussed. The results show that the elastic region of the load versus strain curves is about 90%-95% of the whole, specimens with low confinement factor ?exhibit a rapid softening process in the post-peak region, and a brittle shear failure, while specimens with high confinement factor exhibit a gradual softening process and cause serious bulge in all sections and significant buckling on the top and bottom of the specimen. It is found that high confinement factor and high strength of RPC result in high ultimate loading capacity, the steel tube provides worse confinement to RPC than to the conventional concrete. Equations proposed in this paper agree well with the test results.