The Design of a semi-prefabricated LVL-concrete composite floor

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

Blue Swimmer Crab ( Portunus armatus ) Resource in the West Coast Bioregion, Western Australia Part 2: Warnbro Sound, Comet Bay, Mandurah to Bunbury, Leschenault Estuary, Geographe Bay an d Hardy Inlet

Blue swimmer crabs (Portunus armatus) are found along the entire coastline of Western Australia in a range of estuarine, inshore and continental shelf environments (\u3c50 m). Crab fisheries in the West Coast Bioregion are centred in the estuaries and coastal embayments from the Swan-Canning Estuary south to Geographe Bay. Major commercial and recreational fisheries in this Bioregion include the Cockburn Sound Crab Managed Fishery, the Swan-Canning Estuary Crab Fishery (Area 1 of the West Coast Estuarine Managed Fishery), and the Peel-Harvey Crab Fishery (Area 2 of the West Coast Estuarine Managed Fishery). Refer to Johnston et al. (2020b) for detailed information on these fisheries

Blue Swimmer Crab ( Portunus armatus ) and Sand Crab ( Ovalipes australiensis ) Resource in the South Coast Bioregion of Western Australia

The blue swimmer crab (Portunus armatus) is found along the entire coastline of Western Australia (WA) in a range of estuarine, inshore and continental shelf areas (\u3c50 m). In the South Coast Bioregion (SCB), blue swimmer crabs are retained as by-product in commercial nets of the 25 licences operating in the South Coast Estuarine Managed Fishery (SCEMF) and targeted by purpose-designed crab traps allocated to fishers in Princess Royal and Oyster Harbours in Albany

Preliminary research towards a semi-prefabricated LVL-concrete composite floor system for the Australasian market

The choice of the best floor solution has always been a key issue in the design and construction of multi-storey timber buildings. Strict performance requirements such as effective acoustic separation of inter-tenancy floors, thermal mass, fire resistance, limitation of deflection, resistance to vibrations and effective diaphragm action are very hard to comply with if only timber is used. The main purpose of this paper is to present the preliminary and some ongoing research in the short- and long-term carried out mainly at the University of Canterbury, New Zealand, for the realisation of a semi-prefabricated laminated veneer lumber (LVL)-concrete composite floor system in both the local and Australasian market. The paper discusses a novel semi-prefabricated LVLconcrete composite system where panels made from LVL joists and plywood flooring are prefabricated off-site. Once the panels are lifted onto the supports and connected side-by-side, a concrete topping is cast-in-situ so as to form a continuous slab connecting all the panels. Composite action between the concrete topping and the panels is achieved using different types of connectors, such as various forms of notches cut from the LVL joists and reinforced with coach screws or toothed metal plates pressed in the LVL joists. After pointing out the advantages of the proposed system over traditional only-timber and only-concrete floor solutions, the paper describes push-out tests in the short-term on connections used in the LVL-concrete composite. Tests to failure of small LVL-concrete composite blocks (push-out tests) with different types and shapes of connection systems were performed at the University of Canterbury, New Zealand, and at the University of Technology Sydney, Australia. The results are parametrically evaluated and discussed in detail. The failure mechanism of the notched connection is highlighted together with the strength and stiffness values for each tested connection system. Subsequently, the four best connection systems were identified and used in beam specimens of 8-10 m in span. The experimental program on the beams is presented briefly in order to provide information of the different phases of the project

Blue Swimmer Crab ( Portunus armatus ) and Mud Crab Scylla serrata and Scylla olivacea ) Resources in the North Coast and Gascoyne Coast Bioregions, Western Australia

Blue swimmer crab (Portunus armatus) are found along the entire Western Australia (WA) coast, in a range of estuarine, inshore and continental shelf areas (\u3c50 m). In the North Coast Bioregion (NCB), commercial fishing primarily occurs as part of the Pilbara Crab Managed Fishery (PCMF) which spans the inshore waters from Onslow through to Port Hedland, with most fishing activity taking place around Nickol Bay

Timber-Concrete Composite Floor Beams under 4 Years Long-Term Load

The long-term behaviour of timber-concrete composite is characterized by the response of its three components (timber, concrete and connection) to load, moisture content, temperature and relative humidity of the environment. This paper reports results of a 4-years long-term test on three 8m span laminated veneer lumber (LVL)-concrete composite floor beams under service load performed in an indoor, uncontrolled, and unheated environment at the University of Canterbury. The environmental conditions were characterized by either low temperature with high relative humidity or high temperature with low relative humidity, conditions considered to be reasonably severe and presumably close to service class 3 according to Eurocode 5. The mid-span deflections were extrapolated to the end of service life (50 years) and compared to span/200 deflection limit, which was exceeded by all beams

Blue Swimmer Crab ( Portunus armatus ) Resource in the West Coast Bioregion, Western Australia Part 1: Peel Harvey Estuary, Cockburn Sound and Swan Canning Estuary

Blue swimmer crabs (Portunus armatus) are found along the entire coastline of Western Australia in a range of estuarine, inshore and continental shelf areas (\u3c50 m). In the West Coast Bioregion (WCB), crab fisheries are centred in estuaries and coastal embayments from Geographe Bay to the Swan River. Commercial fisheries include the Cockburn Sound Crab Managed Fishery (CSCMF), the Warnbro Sound Crab Managed Fishery, the Swan-Canning Estuary (SCE) Crab Fishery (Area 1 of the West Coast Estuarine Managed Fishery (WCEMF)), Peel-Harvey Crab Fishery (Area 2 of the WCEMF), Hardy Inlet (Area 3 of the WCEMF) and the Mandurah to Bunbury Developing Crab Fishery (Area 1, Comet Bay and Area 2, Mandurah-Bunbury)

Analytical assessment for comparisons of triple-t precast concrete-timber composite floor using gamma method

Concrete-timber composite floor is a construction technique combining two materials, concrete and timber, connected together using some form of interlayer shear connectors either positioned discretely or continuously along the span of the floor. The interlayer connections provide the desired composite action, where the degree of this composite action is governed by the types of connection system used in the concrete�timber composite system. This analytical method. The analytical method here refers to a design procedure known as Gamma Method recommended in the Eurocode 5 Annex B for bending stiffness, (EI)eff. This quantity obtained experimentally and analytically was compared and the reliability of Gamma method was investigated. concrete-timber composite system. In this method, the specific quantity to express the structural performance of the composite system is the effective paper presents the preliminary study on the structural performance of a proposed triple-T precast concrete-timber composite floor subjected to collapse load. The structural performance derived experimentally through four-point bending collapse test was compared to the same performance established usin

Strength of structural timber members with finger-joints and metal plate connectors

Finger jointing of short off-cuts for structural purposes particularly for lightweight roof truss and prefabricated timber house is likely an economical method of minimizing waste and generating benefits. The primary goal of this research is on the possibility of using finger-jointed timber with metal plate connectors for structural purposes, i.e. in trusses: internal members, top and bottom chord. This research assessed the strength properties of finger-jointed strength group B timber and the influence of number of joints and its positioning on strength. The glue applied for finger jointing is polymer isocyanate adhesive or commercially known as Koyo glue. Bending, compression and tension tests were carried out and the results show that the efficiency of the joints in relation to the strength of the unjointed specimens were greatly influenced by the positioning and number of joints. The results obtained from tests indicated that modulus of rupture decreases with the presence of finger joint while modulus of elasticity is not affected. Tests on the performance of connection with metal plate using finger-jointed timber showed small difference in the basic working load as compared to the unjointed specimens. The study suggests that the combination use of finger-jointed timber with metal plate connector for structural purposes is acceptable depending on the joint efficiency, the position and number of the finger joint in the member, and the type of stresses (i.e. compression, tension or bending) in the member