Analysis of the behaviour of a bonded joint between laminated wood and ultra high performance fibre reinforced concrete using push-out test

摘要

Bonded composite constructions using timber and ultra-high performance fibre reinforced concrete (UHPFRC) are investigated as highly innovative structural elements technically and economically efficient, and having better environmental performances. Such technique could indeed offer new structures typologies for bridges for instance associating timber for main beams with UHPFRC slabs. In timber-concrete-composite structures, connection is traditionally achieved with mechanical means. The research presented herein describes the timber-concrete assembly by adhesive bonding and specially the behaviour of bonded joint between Laminated Wood (LW) and UHPFRC. This type of assembly has to be investigated concerning mainly the durability of the bonded assembly and its ability to transmit the forces concentrated on edges. The present study describes the development of a test called "Push-Out" used to characterize the behaviour of the timber-concrete bonded after or prior to environmental ageing. Following the development of the used test protocol, investigations are realized on four different commercial resins to study the influence of the adhesive stiffness on the force transfer focusing in particular on the failure mode, on the ultimate capacities and some local deformations. The mechanical behaviour of the bonded joint is investigated in particular from a theoretical point of view and from the determination of deformation field obtained by Digital Image Correlation (DIC).