Manufacturing influences of the adhesive layer on the load-bearing capacity of anchor bolts for thick FRP laminates

The subject of this study is the load introduction concept of adhesive bonded anchor bolts for local load transmission into the cross section of fiber-reinforced polymer (FRP) composites. Anchor bolts and glued-in rods are a standardized load introduction in civil engineering. However, this concept is not yet examined for FRP structures in the open literature. The objective of this study is the experimental analysis of macroscopic irregularities induced by the manufacturing process of the adhesive layer. Three properties of the adhesive layer were examined: the thickness due to the position of the bolt, the presence of voids and the contour of the adhesive spew. The manufacturing process was optimized with regard to each property. The influence of the macroscopic irregularities was determined by tensile pull out tests. The results showed that the joint is capable of transmitting high loads into the laminate. The determined influence of the manufacturing process on the mean load-bearing capacity was not distinct, but a defined fillet contour resulted in a very low sample standard deviation.