Bond behavior of mortar grouted GFRP rock bolt

Abstract

Bolt is widely used in slope engineering, tunnel and cavern supporting, and restoration of engineering structure. It can improve the strength and stability of ground, rock mass, and other structures. Traditional steel bolt has some disadvantages, such as easy corrosion, heavy weight. Glass Fiber Reinforced Polymer (GFRP) is impervious to chloride ion and low pH chemical attack, and its tensile strength is much greater than steel while with lighter weight. Those advantages make it a better alternative in some fields of engineering. To utilize GFRP bars as rock bolt, some aspects of its behavior, such as bond strength in mortar, bearing capacity, and bond stress distributing along its interface, have to be determined. This paper presented the research on bonding behavior of anchor bolt made from GFRP bar and concrete block used to model rock in laboratory. The modified pullout tests were conducted on selected GFRP bars that were grouted with mortar in concrete blocks. According to the results of laboratory, bond characteristics of mortar grouted GFRP rock bolts were evaluated.