Experimental Study on Mechanical Properties of Novel FRP Bars with Hoop Winding Layer
Experimental Study on Mechanical Properties of Novel FRP Bars with Hoop Winding Layer
复制标题
新型环向缠绕层FRP筋力学性能试验研究
DOI：
10.1155/2021/9554687
复制
发表时间：
2021-08-04
影响因子：
--
通讯作者：
Guan, Shuai
中科院分区：
文献类型：
--
作者：
Liu, Yue;Zhang, Hong-Tao;Guan, Shuai
由于钢筋易受腐蚀，FRP筋具有重量轻、强度高、耐久性好等优点，已成为普通钢筋的良好替代品。FRP筋具有很高的抗拉强度，但其抗压强度相对较低，往往被忽略，因此FRP筋在受压构件中的应用受到了限制。提出了一种提高FRP筋抗压性能的拉挤-缠绕-拉挤成型新方法。在拉挤FRP芯的外表面缠绕一层环向FRP层，在最外表面还加有纵向拉挤层和筋。本文研究了这种新型环向缠绕层FRP筋的力学性能。首先，对传统和新型GFRP筋进行了单调拉伸和压缩试验。然后，对两种GFRP筋进行了反复拉压试验。试验结果表明，缠绕层GFRP筋的抗压极限承载力比传统GFRP筋提高了10 ~ 20 kN，其抗压延性也得到了提高。此外，两种GFRP筋的拉伸应力-应变行为均为线弹性，缠绕层的增加对GFRP筋的拉伸性能影响不大。循环加载试验中，GFRP筋的抗压极限荷载与单调抗压试验的90%相似，抗拉极限荷载与单调抗拉试验的65%相似，分别为80%和45%。与无缠绕层的GFRP筋相比，新型GFRP筋的整体刚度大于传统GFRP筋，极限荷载也大于传统GFRP筋。此外，由于新型GFRP筋的残余位移大于传统GFRP筋，在芯材外表面缠绕环向纤维是提高GFRP筋耗能能力的有效途径。
Due to the fact that steel reinforcement is vulnerable to corrosion, FRP bars with light weight, high strength, and excellent durability have become a good substitute for ordinary steel bars. FRP bars have high tensile strength, but their compressive strength is relatively low and often neglected, so the application of FRP bars in compression members has been restricted. This paper proposes a new pultrusion-winding-pultrusion method to improve the compressive ability of FRP bars. A hoop FRP layer is winded on the outer surface of the pultruded FRP core, and a longitudinal pultruded layer and ribs are also added on the outermost surface. In this paper, mechanical properties of this novel FRP bar with hoop winding layer are investigated. First, monotonic tensile and compressive tests on traditional and novel GFRP bars were conducted. Then, cyclic tension-compression loading tests were also carried out on the two types of GFRP bars. Test results showed that the compressive ultimate bearing capacities of GFRP bars with winding layers were 10 similar to 20 kN greater than those of the traditional GFRP bars, and the compressive ductility of the novel GFRP bars was also improved. Furthermore, the tensile stress-strain behaviors of both GFRP bars were linear-elastic and the added winding layer did not greatly influence the tensile properties of the GFRP bars. Moreover, for the cyclic loading test, the compressive ultimate load of GFRP bars was 80%similar to 90% of that under monotonic compressive test, and the tensile ultimate load was 45%similar to 65% of that under monotonic tensile test. Compared with the GFRP bar without winding layer, the overall stiffness of the novel GFRP bar was greater than that of the traditional one and the ultimate load of the novel GFRP bar was also greater. In addition, seeing that the residual displacement of the novel GFRP bar was greater than that of the traditional GFRP bar, winding hoop fibers on the outer surface of the core is a useful way to improve the energy dissipation capacity of the GFRP bar.