Although engineered wood products such as glued laminated timber (glulam) and cross-laminated timber (CLT) have successfully eliminated the flaws inherently exist in conventional wood products, they are still not comparable with steel and concrete in terms of strength and stiffness. Among all different options for reinforcement, Carbon Fibre is relatively popular due to its high tensile strength, low weight, and easy installation. This study presents an analysis of flexural stiffness and stress distributions of CLT panels reinforced with carbon fibre mats, based on an analytical method and finite element method (FEM).
This paper describes the design of a novel semi-prefabricated LVL-concrete composite floor that has been developed in New Zealand. In this solution, the floor units made from LVL joists and plywood are prefabricated in the factory and transported to the building site. The units are then lifted onto the supports and connected to the main frames of the building and to the adjacent units. Finally, a concrete topping is poured on top of the units in order to form a continuous slab connecting all the units. Rectangular notches cut from the LVL joists and reinforced with coach screws provide the composite action between the concrete slab and the LVL joists. This system proved to be an effective modular solution that ensures rapid construction. A design procedure based on the use of the effective flexural stiffness method, also known as the “gamma method” is proposed for the design of the composite floor at ultimate and serviceability limit states, in the short and long term. By comparison with the experimental results, it is shown that the proposed method leads to conservative design. A step-by-step design worked example of this novel semi-prefabricated composite floor concludes the paper.
Wood has long been in demand as a competent building material due to its beauty, economy, and ease of construction. Excellent material properties are exhibited by a number of new engineered wood products such as gluedlaminated (Glulam) and cross-laminated timbers (CLT). New experimental data on the structural behaviour of CLT-toGlulam composite-section beams is presented in this paper. Four large-scale test assemblies composed of two different engineered wood sections were tested. Beam composite sections were built of a top flange part made of a cross-laminated timber slab and a web part made of a Glulam rectangular section. The two parts forming each beam section were connected together using 5/16 self-tapping screws in order to create composite action. Results from this research showed that reducing the spacing distance between screws considerably increased the flexural stiffness of the CLT-to-Glulam composite beams.