反复荷载作用下钢-聚丙烯混杂纤维混凝土与钢筋黏结强度研究

发布时间：2018-11-27 10:05

【摘要】：考虑钢纤维和聚丙烯纤维的体积率、长径比等因素的影响,设计制作36个钢-聚丙烯混杂纤维混凝土试件,通过中心拉拔试验,研究低周反复荷载作用下钢-聚丙烯混杂纤维混凝土与变形钢筋间的黏结强度。结果表明:混杂纤维的掺入对混凝土与钢筋间的黏结强度存在正混杂效应,其中钢纤维对黏结强度的提高作用更为明显。对于混杂纤维混凝土,在聚丙烯纤维体积率为0.15%、长径比为167的情况下,当钢纤维体积率从0.5%增长到1.5%、长径比从30增加到80时,黏结强度分别提高了20.57%和14.75%,而聚丙烯纤维体积率和长径比的变化对黏结强度没有明显影响;当混杂掺入体积率为1.5%、长径比为60的钢纤维与体积率为0.15%、长径比为167的聚丙烯纤维时,与相应的单掺钢纤维混凝土、聚丙烯纤维混凝土和普通混凝土相比,黏结强度分别提高了14.64%、31.37%和46.55%。此外,基于厚壁圆筒理论,针对实际受力情况,建立了钢-聚丙烯混杂纤维混凝土与变形钢筋黏结强度的理论模型,计算结果与实测结果吻合良好。
[Abstract]:Considering the influence of volume ratio and aspect ratio of steel fiber and polypropylene fiber, 36 specimens of steel-polypropylene hybrid fiber concrete were designed and made. The bond strength between steel and polypropylene hybrid fiber reinforced concrete and deformed steel bar under low cyclic loading is studied. The results show that there is a positive hybrid effect on the bond strength between concrete and steel bar with the addition of hybrid fiber, and the effect of steel fiber on the bond strength is more obvious. For hybrid fiber concrete, when the volume ratio of polypropylene fiber is 0.15 and the aspect ratio is 167, when the volume ratio of steel fiber increases from 0.5% to 1.5, and the aspect ratio increases from 30 to 80, The bonding strength was increased by 20.57% and 14.75%, respectively, while the volume ratio and aspect ratio of polypropylene fiber had no significant effect on the bond strength. When mixed with steel fiber with volume ratio of 1.5 and ratio of length to diameter of 60 and polypropylene fiber with volume ratio of 0.15 and 167, it is compared with corresponding concrete of steel fiber, polypropylene fiber concrete and ordinary concrete. The bonding strength was increased by 14.64% 31.37% and 46.55% respectively. In addition, based on the thick-walled cylinder theory, a theoretical model of the bond strength between steel-polypropylene hybrid fiber reinforced concrete and deformed steel bar is established according to the actual loading conditions. The calculated results are in good agreement with the measured results.
【作者单位】：武汉大学土木建筑工程学院;
【基金】：国家自然科学基金项目(51278388)
【分类号】：TU37

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