Laminated veneer lumber

About: Laminated veneer lumber is a research topic. Over the lifetime, 1042 publications have been published within this topic receiving 9344 citations. The topic is also known as: LVL.

Development of structural composite products made from bamboo II: fundamental properties of laminated bamboo lumber

Abstract: This experiment explored the technical feasibility of using bamboo zephyr mat with pre-hot-pressed treatment for the manufacture of laminated bamboo lumber (LBL), which is similar in construction to that of laminated veneer lumber (LVL). Six LBL boards (made from four-ply bamboo zephyr mats) with approximate dimensions of 2×42× 42cm were fabricated using resorcinol-based adhesive. The experimental design involved three combinations of layered structures (types I, II, and III) and two LBL loading positions (H-beam and V-beam) during the bending test. These materials were then compared to ordinary LVL. Results indicated that the bending properties (moduli of rupture and elasticity) of LBL were comparable to those of LVL, but there was no significant effect on the physical and mechanical properties among the three types of LBL beam. Interestingly, orienting the glue line to the vertical direction (V-beam) could maximize the ultimate strength of the LBL.

Life-cycle analysis of wood products: cradle-to-gate lci of residential wood building materials

Abstract: This study compares the cradle-to-gate total energy and major emissions for the extraction of raw materials, production, and transportation of the common wood building materials from the CORRIM 2004 reports. A life-cycle inventory produced the raw materials, including fuel resources and emission to air, water, and land for glued-laminated timbers, kiln-dried and green softwood lumber, laminated veneer lumber, softwood plywood, and oriented strandboard. Major findings from these comparisons were that the production of wood products, by the nature of the industry, uses a third of their energy consumption from renewable resources and the remainder from fossil-based, non-renewable resources when the system boundaries consider forest regeneration and harvesting, wood products and resin production, and transportation life-cycle stages. When the system boundaries are reduced to a gate-to-gate (manufacturing life-cycle stage) model for the wood products, the biomass component of the manufacturing energy increases to nearly 50% for most products and as high as 78% for lumber production from the Southeast. The manufacturing life-cycle stage consumed the most energy over all the products when resin is considered part of the production process. Extraction of log resources and transportation of raw materials for production had the least environmental impact.

Bamboo: An Alternative Raw Material for Wood and Wood-Based Composites

Abstract: Bamboo is the most important non-wood species which is abundantly grows in most of the tropical and subtropical zone. It has developed as a specially valuable and superior alternate for wood composite manufactured, such as for pulp and paper, stripboards, matboards, veneer, plywood, particleboard and fiberboard. Moreover, several researches have used it as raw material for structural composites such as Oriented Strand Board (OSB), Glue Laminated Timber (GLT), Parallel Strip Lumber (PSL) and Oriented Strand Lumber (OSL). Nowadays, there are many kinds of bamboo composite are produced and traded in the world. However, there are several differences between bamboo and wood for example macroscopic and microscopic characteristics, chemical composition, physical and mechanical properties. For this reason, the methods, technology and equipment for wood processing cannot be directly applied in bamboo utilization. Further research is noticeably required on the information on bamboo properties, cost-effective technologies and managements. With modern techniques and adapted technologies, bamboo can be processed into a wide range of products which successfully compete with wood and other raw materials in the future.

Connections for composite concrete slab and LVL flooring systems

Abstract: Composite concrete slab and timber flooring systems are commonly used in many parts of the world to exploit the high strength-to-weight ratio of timber and the good acoustic separation provided by concrete floor slabs. This paper describes the results of an experimental programme that investigated the suitability of a range of connectors to transfer shear between a concrete slab and a laminated veneer lumber (LVL) beam. Shear tests on reduced scale specimens were performed with the aim of comparing the strength, stiffness, and post-peak performance of different connectors such as round and rectangular concrete plugs with and without screw and steel pipe reinforcement, proprietary (SFS) screws, coach screws with different diameters, sheet brace anchors, and framing brackets. The rectangular concrete plug reinforced with a coach screw was found to provide the greatest stiffness and strength, as well as favourable post-peak behaviour. Such a system can be used for cost-effective composite floor systems due to its efficient cost-to-capacity ratio, which reduces the number of connectors needed along the beam axis to achieve the composite action.

Seismic design of multi-storey buildings using Laminated Veneer Lumber (LVL)

Abstract: The recent development of laminated veneer lumber (LVL) as an alternative to solid timber or glue-laminated timber has greatly improved the viability of structural timber for the seismic design of certain types of buildings. The low mass, flexibility of design and rapidity of construction all create the potential for increased use of LVL timber in low-rise multi-storey buildings. Based on recent developments in the seismic design of precast concrete for multi-storey buildings, proposals are made for innovative types of jointed ductile connections in LVL timber buildings, based on post- tensioning techniques to assemble structural members for both frame and wall systems. This contribution gives an overview of an going comprehensive research project involving both numerical and experimental investigations. The extremely satisfactory preliminary results of quasi-static cyclic tests of exterior beam-column joint subassemblies are presented as a confirmation of the expected high seismic performance of the proposed solutions for LVL seismic resisting systems.