大直径玻璃纤维增强聚合物复合材料抗浮锚杆外锚固性能试验及黏结-滑移模型

玻璃纤维增强聚合物(GFRP)复合材料抗浮锚杆与建筑物混凝土底板的锚固效果关乎整个结构的安全性和稳定性。为深入探究GFRP复合材料抗浮锚杆与混凝土底板之间的锚固性能,本文通过自行设计的足尺锚杆对拉试验装置对不同锚固形式的GFRP复合材料抗浮锚杆进行抗拔试验,测定锚杆极限抗拔承载力及杆体与混凝土间相对滑移量。试验结果表明,采用新型应力分散锚具锚固的GFRP复合材料抗浮锚杆外锚固段锚固效率均在80%以上,与混凝土间滑移量均大于裸筋直锚试件,证实该新型应力分散锚具可有效提升GFRP复合材料抗浮锚杆外锚固效果。在双曲线模型基础上提出一种新型的描述GFRP复合材料抗浮锚杆与混凝土黏结-滑移关系上升段本构模型,该模型综合考虑杆体直径及锚固长度对锚杆杆体与混凝土间黏结-滑移本构关系的影响,模型预测结果与本次试验结果吻合度较高,并对模型的合理性和准确性进行了验证。

External anchorage performance test and bond-slip model of large diameter glass fiber reinforced polymer composite anti-floating anchor

The anchoring effect of the glass fiber reinforced polymer (GFRP) composite anchors and the concrete floor of the building is related to the safety and stability of the entire structure. In order to deeply explore the anchoring mechanism between GFRP anchors and concrete, the GFRP composite anti-floating anchors of different anchoring forms were tested by the self-designed full-scale anchor pull-pull test device to determine the ultimate pull-up bearing capacity of the bolt and the relative slip between the rod and the concrete. The test results show that the anchoring efficiency of the external anchorage section of GFRP composite anti-floating anchors anchored by new stress-distributed anchor is above 80%, and the relative slippage of concrete is larger than that of bare-strand direct anchoring specimens, confirming the new stress-distributed anchors can effectively improve the anchoring effect of the external anchorage section of GFRP composite anti-floating anchors. In addition, it was proposed to introduce the material reference coefficient based on the hyperbolic model, and the influence of GFRP composite anchor diameter and external anchor length on the bond-slip constitutive relationship between the anchor rod and the concrete was comprehensively considered in order to establish a new type of GFRP composite anchor and concrete bond-slip curve. The model prediction results are consistent with the test results, and the rationality and accuracy of the model are verified.