| 摘要: |
| 为研究螺纹玻璃纤维增强复合材料（GFRP）筋与混凝土界面的黏结性能,选用不同直径的GFRP筋材制备3组拉拔试件,标准养护28d后开展中心拉拔试验.试验结果表明：GFRP筋与混凝土的黏结强度随其直径的增大而增大,拉拔试件的破坏模式和黏结应力滑移曲线也随之变化;当GFRP筋直径较小(8、12mm)时,拉拔试件主要发生筋材拔出破坏,但2种直径下的黏结应力滑移曲线在弹性上升段后存在较大差异,直径8mm筋材的拉拔试件呈来回波动趋势,且渐趋平缓,而直径12mm筋材拉拔试件表现为下降后又上升的双曲线模式;当GFRP筋直径较大(16mm)时,拉拔试件发生劈裂破坏,其黏结应力上升到最高点后迅速下降.最后,基于弹性力学厚壁圆筒理论模型,对不同直径螺纹GFRP筋的黏结破坏面夹角θ进行探讨并提出了黏结强度计算公式,通过与相关试验结果的对比分析,验证了该计算公式对发生筋材拔出破坏的情况具有非常好的预测精度. |
| 关键词: GFRP筋 拉拔试验 黏结性能 理论模型 强度预测 |
| DOI：103969/j.issn.1007 9629202104029 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51878319,51578267);江苏省“六大人才高峰”高层次人才选拔培养资助项目(2015 JZ 008) |
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| Experimental and Theoretical Calculation of Bonding Performance between Threaded GFRP Bars and Concrete |
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SONG Zepeng, LU Chunhua, XUAN Guangyu, CAI Qiming, BU Senzhuang
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Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013, China
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| Abstract: |
| In order to study the bonding performance of the threaded glass fiber reinforced polymer(GFRP) bar and the concrete interface, three groups of pullout specimens were prepared from several GFRP bars of different diameters. A central pullout test was conducted on these specimens after 28d standard curing. Experimental results show that the bonding strength between GFRP bar and concrete increases as the bar diameter increases. The failure modes and bonding stress slip curves of GFRP bars of different diameters change accordingly. For the GFRP bars with small diameters of 8mm and 12mm, the tested specimens are mainly pulled out and damaged, but the bonding stress slip curves in the two cases also differ greatly after the stage of elastic rise. The test specimens of the diameter of 8mm tend to fluctuate back and forth, and gradually flatten. While the bonding stress of the pullout specimen with a bar of diameter of 12mm continues to rise and then decreases, showing a hyperbolic mode. When the diameter of GFRP bars becomes larger(16mm), the splitting damage appeares in the specimens tested. After the bonding stress slip curve rises to the highest point, the bonding stress decreases rapidly. Finally, based on the theoretical model of the thick walled cylinder of elastic mechanics, the angle of the bonding failure surface of the threaded GFRP bars of different diameters was discussed and the formula for calculating the bonding strength was proposed. The comparative analysis with the relevant test results verifies that the calculation formula has excellent prediction accuracy for specimens with pullout failure. |
| Key words: glass fiber reinforced polymer(GFRP) bar pullout test bonding performance theoretical model strength prediction |
