This paper reports results from a series of static tests on resin injected bolted joints with pultruded Fibre Reinforced Polymer (FRP) material. The aim is to characterise a method of connection that could be fatigue and slip resistant. For comparison, tests are also carried
out on standard bolted connections without resin and with 2 mm clearance holes. Slip in joints is a major issue in bridge engineering, which has to be controlled if the structural scheme is to perform satisfactorily over its service life. The transfer of connection force in FRP joints, by way of frictional force, say by using High Strength Friction Grip (HSFG) bolts, cannot be relied upon [1], because steel bolting is known to lose its pre-tension with time due to the viscoelastic properties of the FRP.
The aim of our preliminary study is to offer a potential solution to developing a suitable slip resistant connection. Tests are conducted on double lap-shear joints according to Annex G of BS EN 1090-2:2008 [2]. The hexagon
injection bolts and bottom washer are prepared as per Annex K of the same standard. A new top washer has been designed and tested to ensure smooth resin filling in the cavity between bolt (M16) and 2 mm hole clearance. It is expected that resin injected bolting will
provide a mechanical fastening system that has locking capabilities. If successful the outcome of our research will address the challenge of durability and will ensure longer
service lives for joint limit states under bridge loading. The results will also help in preparation of recognised design guidelines for FRP bridges
