Sustainable application of wood in civil engineering

Sustainability is an integral part of all rail, ground, water and road construction projects by 2020. It is important to properly combine People, Planet and Prosperity to achieve sustainable development. When you look at construction speed, sustainability and the possibility for circular construction, you also look at the application of wood.

Wood and wood products are renewable, biobased and reusable and are therefore already being used more and more often. In recent years, many wooden applications have already proven successful in practice. It is impossible to imagine the Dutch landscape without them: think of bridges, jetties, sheet piling, sheet piling, guard rails, fenders and lock gates. 

Encouraging wood use
The Department of Public Works also encourages the use of wood. In many cases, it is the responsible party for its management and maintenance. The extraction, production, transport and processing of wood into new raw material is often the business of third parties. Staatsbosbeheer has traditionally contributed to timber production in the Netherlands. John van der Haas, project manager at Staatsbosbeheer says, "Our forests are managed in a sustainable way, according to FSC guidelines and our own forest vision 'Growing Future'. We harvest some 3,000,000 m³ wood at a sustainable level: i.e., more wood grows in our forests than is harvested. Because trees absorb CO₂ and retain them even after harvesting and processing, wood is one of the most environmentally friendly building materials. We ensure that the wood from felled trees from our areas is used in the highest quality possible." As an example, Van der Haas mentions recreational area IJsselmonde with the Rhoon and Carnisse Grienden. Two outlying dike areas filled with pollard willows. The areas are maintained by Van Aalsburg Griendhoutthandel. "In a multi-year cycle, the pollard willows are cut/pruned. The wood that comes off them is used in all kinds of hydraulic engineering projects, such as sinkers for bottom and bank protection. Completely circular." 

A sinker is a mat constructed from rowwood (willow), with a layer of cradles (roll of rowwood, machine-wrapped with sisal rope) on top.

New trend
Van der Haas: "Where before everything was replaced indiscriminately, we now see that people are looking at whether repair is sufficient. Until a year ago, it mattered. Increasingly, the choice is then made on the basis of sustainability. The costs and environmental aspects of the entire life cycle are taken into account, proving that wood is not only an environmentally friendly product, but also does not have to be more expensive than other products. Using more wood makes a direct contribution to CO₂-reduction and making the GWW sector more sustainable," Van der Haas concluded.