Project contact is Luca Sorelli at Université Laval
This project aims to develop a new precast wood / concrete floor system that can push the span limits in multi-storey wood buildings. The multidisciplinary methodology includes a finite element analysis technique using the “DDuctileTCS” software developed at CIRCERB, shear tests on connections, bending tests of the composite beam and an extension of technical standards for the design of composite structures. This project will develop solutions to optimize the composite action and vibration of long-span precast and mixed floors. The methodology consists of: (i) analysis of systems and optimization of shapes by numerical finite element techniques; (ii) connection shear tests; (iii) proof of concept on a prototype beam in the laboratory.
Nail-laminated timber-concrete composite (TCC) is a system composed of a nail-laminated timber (NLT) panel connected to a concrete slab through shear connections. When used as flexural elements such as floors, the concrete and NLT are located in the compression and tension zones, respectively...
CLT-concrete composite floor systems are a solution for timber buildings with a long-span floor. It yields a reduction of carbon footprint and even eco-friendly structure at the end of its service life. This study will evaluate the structural performance of notched connectors in the CLT-concrete composite floor, comprised of the serviceability stiffness, maximum load, and behavior at failure. The parameters of the test plan are the loaded edge length, the notch depth, the concrete thickness, and the screw length. Other secondary variables are also assessed, such as different loading sequences, speed of test, and timber moisture content. Experimental results prove that the performance of the connector depends significantly but not linearly on the notch depth and the length of the loaded edge. The connector with a deeper notch and a shorter heel will be stiffer and more robust, but it also tends to have a brittle rupture. The test results also help validate a solution for deconstructable connector systems. A nonlinear finite element model of the connector is built and validated versus the experimental results. It yields reasonably good predictions in terms of resistance and can capture the load-slip relationship.
As part of its research work on wood buildings, FPInnovations has recently launched a Design Guide for Timber-Concrete Composite Floors in Canada. This technique, far from being new, could prove to be a cost-competitive solution for floors with longer-span since the mechanical properties of the two materials act in complementarity. Timber-concrete systems consist of two distinct layers, a timber layer and a concrete layer (on top), joined together by shear connectors. The properties of both materials are then better exploited since tension forces from bending are mainly resisted by the timber, while compression forces from bending are resisted by the concrete. This guide, which contains numerous illustrations and formulas to help users better plan their projects, addresses many aspects of the design of timber-concrete composite floors, for example shear connection systems, ultimate limit state design, vibration and fire resistance of floors, and much more.
For the design of timber-concrete composite (TCC) elements with notches, the slip modulus Kser represents an important property of the connection. In this paper available research results were gathered and further experimental tests were carried out in order to define the slip modulus of a notched connection. Therefore experimental...
Timber-concrete-composite (TCC) floors are a successful example of hybrid structural components. TCC are composed of timber and concrete layers connected by a shear connector and are commonly used in practical civil engineering applications. The connection of the two components is usually achieved with mechanical fasteners where relative slip cannot be prevented and the connection cannot be considered rigid. More recently, an adhesively bonded TCC system has been proposed, and has been shown to perform predictably under static short-term loading. One of the main considerations when designing TCC floors is their long-term performance. In the research presented herein, two adhesively bonded TCC beams were exposed to serviceability loads for approximately 4.5 years. During this time the environmental conditions and the deflections were monitored. After having been loaded for 4.5 years, the beams were tested to failure, resulting in findings that long-term loading caused no degradation of the adhesive bond. This research provides input data to develop design guidance for adhesively bonded TCC under long-term loading.
In the presented paper, results of theoretical and experimental investigation of timber-concrete composite members with adhesive connection are described. For the timber part of composite beams Cross Laminated Timber and for concrete part lightweight concrete was used. For the composite connection special adhesive to bounding wet...
Project contact is Luca Sorelli at Université Laval
To minimize the built-in energy of the floor, we need to replace the current system with lighter solutions that retain the key features for robustness and maintenance, and are cost-effective and easy to build (Spadea et al., 2015). This project aims to explore innovative flooring solutions that make up a light wood load-bearing structure reinforced underneath by naturally occurring polymeric fibers (FRP) (Bencardino and Condello 2016), which work well in tension, and above an Ultra-Thin Ultra High Performance Concrete Slab (UHPC) that works exceptionally well in compression. Considering the application of very large floors in multi-storey buildings, the following key questions will be addressed: 1) what form should such a system have, 2) how will this be analyzed, and what mode of failure will be desirable? (3) what practical limitations would be imposed by constructability, (4) what would be the gain on economic cost and environmental impact from a life cycle analysis point of view, and (5) is possible to use biosourced epoxy for connections. The methodology consists of: (i) systems analysis and shape optimization using finite element numerical techniques, (ii) connection shear tests, and (iii) proof of concept on a beam prototype.