Shear strength of steel and CFRP to timber interface

Adhesives can be used to form load-bearing joints in timber structures, both in repair and in new-build applications. An efficient and cost-effective method of making joints is to use rods or dowels or plate, bonded into pre-drilled holes in timber elements, by using structural adhesive for transferring structural loads between such elements. An adhesive is expected to hold materials together and transfer design loads from one adherend to other within a given service environment for the life of the structure. The behavior of the joints depends on many parameters such as glue-line thickness, types of rods, types of adherends etc. This paper reports the behavior of bonded-in joint by varying the plate types (steel and carbon fiber reinforced plastic (CFRP) plates) and timber types (Keruing and Kempas). To characterize the performance of the bonded-in joints, a series of test were conducted such as pull-out test and block shear test. As the strength properties of the joint greatly affected by the adhesive, the mechanical properties of the adhesives were also determined by conducting flexural and tensile test. The results show that the shear strength of bonded-in joint using CFRP plate is higher than bonded-in joint using steel plate.