Use of a single lap shear test to characterize composite-to-concrete or composite-to-steel bonded interfaces

Adhesively bonded composite reinforcements are increasingly being used for civil engineering structures. For an adequate use of such a technique, a better knowledge is needed regarding the stress transfer mechanisms involved in polymer joints. This article introduces a single lap shear test for the characterization of the composite-to-concrete or composite-to-steel bonded assemblies. In the first part, an extensive description of the test set-up is given and various methods are proposed to analyse the experimental results. According to Chen's classification (2005) [1], the test under consideration is a near-end supported single-shear test. A first series of tests is reported, that investigates the differences between reinforcement processes based on either pultruded laminates or impregnated carbon fabrics (wet lay-up method), both used for the strengthening of civil infrastructures. The following part discusses the influence of the distance between the extremity of the concrete specimen and the free edge of the adhesive layer. Finally, differences between bonding on concrete and bonding on steel substrates are investigated in a last part. These experimental investigations have allowed us to build-up a considerable body of experience on such usual composite reinforcements, and a large database on this experimental setup and its interpretation.