箍筋约束对小偏心加载下高强RC柱尺寸效应影响分析

发布时间：2018-02-20 23:08

本文关键词： 高强混凝土柱尺寸效应箍筋约束作用箍筋率小偏心受压加载　出处：《中国科学:技术科学》2017年04期 　论文类型：期刊论文

【摘要】：旨在揭示箍筋约束作用对高强钢筋混凝土(RC)柱在小偏心(e_0=0.25h_0)受压加载下尺寸效应行为的影响.开展了最大横截面尺寸为800 mm×800 mm的12组几何相似的配箍率为0和0.66%的高强混凝土柱试验,此外,建立了钢筋混凝土柱力学行为分析的细观尺度分析模型,并在模拟与试验结果吻合良好的基础上,补充开展了更大配箍率柱(即:1.2%和2.4%)的数值试验,进而对偏心受压加载下柱的力学行为,包括破坏模式、名义受压应力,应变关系、承载力、名义压缩强度及峰值后软化行为等进行了研究,并对其名义压缩强度的尺寸效应进行了分析,进而揭示箍筋约束作用对小偏心加载高强钢筋混凝土柱破坏行为及尺寸效应影响机制,结果表明:1)小偏心受压加载下高强钢筋混凝土柱名义压缩强度存在明显的尺寸效应;2)Bazant尺寸效应律能够较好地描述钢筋混凝土柱在偏心受压加载下的尺寸效应行为;3)箍筋约束作用能够明显提高钢筋混凝土柱的强度及延性,且会削弱其尺寸效应;4)本文建立的细观数值模型能够很好地表征钢筋混凝土柱力学性能.
[Abstract]:The purpose of this study is to reveal the effect of stirrups on the size effect of high strength reinforced concrete (RC) columns under compression loading. Twelve groups with maximum cross section sizes of 800mm 脳 800mm and geometric similar hoop ratios of 0 and 0.66% have been developed. High strength concrete column test, In addition, a mesoscale analysis model for mechanical behavior of reinforced concrete columns is established. On the basis of good agreement between the simulation and the experimental results, numerical tests of larger hoop ratio columns (I. e., 1.2% and 2.4%) are carried out. Then the mechanical behavior of columns under eccentric compression, including failure mode, nominal compressive stress, strain relationship, bearing capacity, nominal compressive strength and post-peak softening behavior, are studied. The size effect of nominal compressive strength is analyzed, and the influence mechanism of stirrups restraint on the failure behavior and size effect of small eccentric loaded high strength reinforced concrete columns is revealed. The results show that the size effect of nominal compressive strength of high strength reinforced concrete columns under small eccentricity compression is obvious. The size effect law of Bazant can well describe the size effect behavior of reinforced concrete columns under eccentric compression. 3) the strength and ductility of reinforced concrete columns can be obviously improved by the restraint of stirrups. The mesoscale numerical model established in this paper can well characterize the mechanical properties of reinforced concrete columns.
【作者单位】：北京工业大学城市减灾与防灾防护教育部重点实验室;
【基金】：国家自然科学基金创新研究群体项目(批准号:51421005)资助
【分类号】：TU375.3;TU311

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