Experimental Study and Numerical Simulation on Bonding Behavior of the New HB-FRP Strengthening Technology

Abstract

To find an alternative way of improving bonding and restricting sliding displacement, a new technique that combines fiber-reinforced polymer (FRP) surface adhesion [externally bonded FRP (EB-FRP)] with a new type of mechanical fastening, namely hybrid bonding (HB-FRP), is developed. The beam specimens are investigated and compared in a new modified beam-shear program to examine the bonding behavior of HB-FRP and EB-FRP. The finite element analysis is conducted to simulate the interfacial shear on the basis of different bolt pretension force by Pretension 179 element and compact pairs of ANSYS software. Also the anchoring parameters of the hybrid bonding of FRP are studied by a drawing test program to study the anchor depth of screw bolts and by the finite element analysis to simulate the contact compression stress on the basis of different sizes of capping plate and bolt pretension for the selection of the capping plates and bolts. On the basis of experiments and the finite element analysis, the formula of calculating FRP anchor length is suggested. The results show that the new HB-FRP is a more reliable strengthening technique. The new bolt-fastening technique does not rely on bearing to transmit the interfacial shear, but increases the interfacial bond by resisting the separation of the FRP laminate from the concrete substrate by the bolt pretension instead. This study contributes to direct the design and the construction of the new HB-FRP directly.