碱环境下拉挤型玻璃纤维聚氨酯螺柱性能的试验研究

为研究拉挤型玻璃纤维聚氨酯螺柱在碱环境下的相关性能,对直径12 mm的拉挤型玻璃纤维聚氨酯螺柱与M12型普通钢制螺栓在pH=13的氢氧化钠溶液环境下进行试验对比,并与常规环境下的性能进行比较,得出如下结论:(1)在常规环境下和1 000 h的pH=13碱环境浸泡下,拉挤型玻璃纤维螺柱和普通钢制螺栓的抗剪承载力基本不变,且拉挤型玻璃纤维螺柱的抗剪承载力约为普通钢制螺栓抗剪承载力的70%~80%;(2)拉挤型玻璃纤维螺柱破坏为脆性破坏,破坏前会听到“丝丝”响声,试件内纤维逐渐被剪断,最终试件由于抗剪承载力不足被破坏;(3)碱环境对拉挤型玻璃纤维螺柱的影响较大,其腐蚀程度随浸泡时间的延长而不断增大,螺柱表面逐渐有纤维颗粒掉落,螺纹部分甚至出现缺口,导致安装时无法施加预紧扭矩而不适合继续使用。

Experimental Research on the Properties of Pultrusion Type Glass Fiber Polyurethane Studs in Alkaline Environment

In order to study the relative performance of pultrusion type fiberglass polyurethane stud in alkali environment, the pultrusion type fiberglass polyurethane stud with diameter of 12 mm and M12 type ordinary steel bolt were tested and compared in sodium hydroxide solution with pH value of 13, and the performance was compared with that in conventional environment. It is concluded that the shear capacity of pultrusion type glass fiber stud and common steel bolt is basically unchanged under the normal environment and the alkali environment of 1 000 h with pH value of 13, and the shear capacity of pultrusion type glass fiber stud is about 70%~80% of that of common steel bolt. The failure of pultrusion type glass fiber stud is brittle failure. Before failure, the sound of "silk" will be heard, and the fiber in the specimen will be cut off gradually. Finally, the specimen will be damaged due to insufficient shear bearing capacity. The alkali environment has a greater influence on the pultruded glass fiber studs, and its corrosion degree increases continuously with the immersion time. Fiber particles gradually fall on the surface of the studs, and the threaded parts even have gaps. As a result, the pre-tightening torque cannot be applied during installation and it is not suitable for continued use.