Efficiency of adhesive layers in strengthening schemes of concrete elements

Abstract

<p>This study quantifies the efficiency of different type of adhesive layers of strengthening schemes for concrete elements. Two different Carbon Fiber Reinforced Polymer (CFRP) types are examined: a) laminated sheets and b) prefabricated plates. The systems were integrated onto concrete substrates using adhesives: i) standard plate epoxy, ii) epoxy of dry impegnation and iii) toughened adhesive. The interface response was investigated experimentally with double-lap shear tests. The efficiency was quantified with a novel semi-empirical proposed index, IC (interface capacity), representing the failure mechanism and the response type. Values close to 1 denotes a linear fully elastic performance leading to abrupt brittle failure whereas, higher values correspond to more plastic response and progressive debonding. The experimental results validated finite element simulations to define the values of IC, matching the shear response and the failure pattern of the CFRP system.</p>