玻璃纤维聚合物约束混凝土圆柱简化分析模型

Simplified analytic models for glass fiber-reinforced polymer-confined concrete circular columns

混凝土圆柱受到有效的侧向约束后,其强度和延性都有不同程度的提高.粘贴玻璃纤维布约束混凝土施工方便,质量可靠.但在设计时,需要合适的分析模型用来保证计算结果的正确性.若采用以往基于钢筋约束混凝土的分析模型会过高估计GFRP材料的约束作用,导致计算结果偏于不安全.共进行了27根(9组)混凝土圆柱试验,其中一组试件未贴布直接试验以便观察其破坏模式,其他8组试件贴布后进行试验.结果表明,加固后柱的强度和变形能力都有了显著提高.基于试验结果,并参考其他研究者的研究成果,提出了一种双线性分析模型,计算结果与试验结果基本吻合.

When circular concrete column is confined effectively by lateral pressure, its strength and ductility can be greatly enhanced. It is convenient and reliable to confine concrete by bonding GFRP sheets. In practical design, an appropriate analytic model should be given to assure reliable results. Previous models generally led to the overestimation of the strength of FRP and resulted in unsafe design. So, experiments on 27 (9 groups) concrete circular columns were conducted. A group of specimens were tested in the 'as built' condition to investigate the failure modes, and other eight groups were tested after retrofitted with bonding GFRP sheets. It is proved that the strength and the ultimate strain of retrofitted columns are improved significantly. Based on test results and other people′s researches, a bilinear analytic model is provided, and a good agreement between test results and theoretical ones is achieved.