A timber guardrail for highways made with hardwoods

A timber guardrail made of sustainable tropical hardwoods has been developed in the Netherlands. The guardrail is an environmentally friendly alternative for zinc-coated steel barriers. The guardrail is made of a combination of two durable hardwood species: angelim vermelho (Dinizia excelsa) from Brazil and azobé (Lophira alata) from Africa....

Strength grading of hardwoods using transversal ultrasound

Detection of local wood inhomogeneities is important for accurate strength and stiffness prediction. In hardwood specimens, visual characteristics (e.g. knots or fibre deviation) are difficult to detect, either with a visual surface inspection or by the machine. Transversal ultrasound scan (TUS) is a non-destructive evaluation method with high...

Influence of slope of grain on the mechanical properties of hardwoods and the consequences for grading

The main parameter that influences the bending strength of timber from tropical hardwood is the slope of grain. Although in the grading rules a specific threshold value is given, in these hardwoods the global slope of grain is very difficult to quantify by a visual assessment. The slope of grain measured after testing gives a better indication,...

Yield optimization and surface image-based strength prediction of beech

Wood is a strongly anisotropic and heterogeneous material with natural defects that are affecting the uniform scatter of the fiber patterns. European beech (Fagus sylvatica) is the species, used for this study. The logs of these species have generally complicated shapes with frequent curvatures, which is in contrast to most of the softwood...

Vertical Forest Engineering: Applications of Vertical Forests with Self-Growing Connections in High-Rise Buildings

Living architecture is thriving. The integration of buildings with vegetation has become a necessity in many metropolitan areas of the world today, including Singapore, New York City, Shanghai and Milan, to name a few. It expands the potential of vertical and horizontal, exterior and interior, exposed and enclosed spaces in a building that can...

Biodynamic timber sheet pile – vegetation retaining structure

Timber sheet pile walls are widely used for the protection of stream banks in different parts of the world. However, there is tendency of creating more sustainable types of stream banks not only because exploitable wood is more difficult to obtain, but also because of disturbance to the natural habitat of plants and animals due to hard...

Vertical Forest Engineering: Applications of Vertical Forests with Self-Growing Connections in High-Rise Buildings: Poster presentation

Living architecture is thriving. The integration of buildings with vegetation has become a necessity in many metropolitan areas of the world today, including Singapore, New York City, Shanghai and Milan, to name a few. It expands the potential of vertical and horizontal, exterior and interior, exposed and enclosed spaces in a building that can...

Testing and modelling of hardwood joints using beech and azobé

Tests on double-shear steel-to-timber joints loaded parallel-to-grain were undertaken, using beech and azobé with one, three and five dowels in a row. The dowels were made of high strength steel (hss) and very high strength steel (vhss). The experiments have shown a significant difference in load-carrying capacity of joints with vhss and hss...

Machine strength and stiffness prediction with focus on different acoustic measurement methods

Strength grading is an important step for the production of homogenous and high-quality solid wood material. In particular, for hardwoods, the use of non-visible characteristics is indispensable. Dynamic MOE (MOEdyn) is an important parameter widely used for grading of softwoods and applicable to hardwoods as well. There are two common ways to...