超高强混凝土短柱受剪强度的试验研究

Experimental study on shear strength of super-high-strength concrete short columns

近年来,随着现代建筑向大跨、高层方向发展,超高强混凝土(高于C100)正得到日益广泛的应用。超高强混凝土的优异性能是具有更高的强度和更好的耐久性,但随着混凝土强度等级的提高,呈现出愈来愈显著的脆性。建筑物承重柱的设计是关系到建筑物在大震下能否倒塌的关键。现行《混凝土结构设计规范》(GB50010-2002)中规定混凝土强度等级的适用范围为C15~C80,目前对超高强混凝土框架柱受剪强度的研究并不多见。实际工程的需要和现行规范、规程指导的脱节形成的矛盾变得日益尖锐。针对上述现状,本文开展了在低周反复荷载作用下,14根超高强混凝土框架短柱受剪强度的试验研究,其混凝土的强度变化范围为95.6MPa^118.6MPa。通过试验,研究了短柱的破坏形态。根据试验结果,框架短柱受剪强度偏下限,提出了可供实际工程设计参考的超高强混凝土框架短柱的受剪承载力计算公式,计算结果与试验值较为吻合。

Recently,super-high-strength concrete(above C100) is more and more widely used because of its good capability of meeting architecture needs of high-rise buildings,long-span.Super-high-strength concrete(SHSC) has been shown to have advantages such as higher strength and better durability.But with the concrete grade rising,SHSC becomes more and more brittle.The design of bearing columns is the key to prevent architecture collapse in the earthquake.In China,the concrete strength grade is C15~C80 in the new applying 'Code for design of concrete structures'(GB 50010-2002).However,now there is very little of correlative research on shear strength of reinforcement super-high-strength concrete columns.The contradiction between engineering requirement and current code or specification becomes more and more serious.In order to solve the above-mentioned problems,the shear strength of 14 SHSC short columns subjected to low cyclic reversed lateral loads was studied,with the concrete strength ranging from 95.6 MPa to 118.6MPa.The failure patterns of specimens were analyzed.According to the low limit values of experimental results,the suggested formula for calculating shear strength of SHSC columns were presented.The calculated results were corresponding with that of the experiment very well.