New wood composite bridges

This research explores the possibilities of wood composite structures with a view to designing durable lightweight composite decks. The paper examines a new wood structure technology in which an ultra-high-performance fiber-reinforced concrete (UHPFRC) slab is fastened to glulam beams. Fasteners representing most existing groups are first experimentally investigated on small beams (span one meter). The modes of functioning of each type and the various failure modes are identified. The paper proposes a method for assessing the interface shear stiffness. This method is based on analysis of flexural test results using a slip versus shear stress relation. It is shown that glued assembly of the two materials yields the best shear stiffness and highest ultimate strength. The practical aspects of surface preparation before gluing are considered. The results of a bending test carried out on a composite structure having a span of three meters, made of UHPFRC glued to two glulam beams, validate this fastening technique.