Toutes vos questions à :
|Usages du robinier aux Etats unis.
|Mobil : 0032 472 84 24 00
Planting the Next
Generation of Waterproof Lumber
Black locust excels in hardness and durability, so pioneers cut it for fence posts. Shipbuilders, though, preferred it for masts.
When English naturalist Mark Catesby first visited Jamestown, Virginia, 100 years after its founding, he saw only the stark ruins of what the first inhabitants in 1602 had called home. But at each corner of the tumble-down huts remained a post-as solid as the day it was erected. He marveled at the still-sound wood, which had been named "locust" after an old-world look-alike.
Other colonists eventually learned of locust's longevitiy, too, because the tree became widely used. No wonder.
Black locust (Robinia pseudoacacia), as it has come to be called, offers superb qualities. Because a locust's trunk contains mostly sapwood, it's strong. In drying, locust hardly shrinks. In stiffness, it outdoes hickory. Fighting decay, it outlasts white oak. Burned, a cord of black locust throws off the heat of a ton of coal. And machined and sanded, the wood takes on a high luster.
Yet, black locust has never attained commercial status. That's because in most of the areas where it grows the tree suffers from insect attack, leaving few trees sound enough to harvest. So instead of becoming commercial lumber, black locust winds up as fence posts, firewood, and railroad ties. Except for one fleeting moment of historical greatness, that's the way it has always been.
You see, a variety of black locust, caringly cultivated in the late 18th century in New Jersey and New York-especially Long Island-earned renown. The tree's straight, branchless trunk proved perfect for shipmasts. Even today in the area, you can still find examples of those once sought after "shipmast locusts."
We built our house in 1977
and there was an old black locust stump cut off flush with the ground
that had been there what appeared to be a long time. It is still there
and looks just like it did 37 years ago. My father and I build fence with
black locust posts in the early 1950s and it was so hard that we held
the fence staples with pliers to drive them into the posts. Some of those
post are still standing and have outlasted the fence that was attached
to them. So much for steel vs locust
In Coloma CA the 12" by
12" corner fence post, at the bridge end of the levee on the Gallagher
Ranch, (now state park) was hand hewn and placed by my Daddy's (Melvin
Francis Gallagher) father and grandfather in the mid 1800's. It is untreated
Black Locust and is still intact today. Dad said that it was the only
thing Locust was good for. It is so wonderful to be able to touch something
that so many generations before have also touched.
Splinters? Not a problem: contact surfaces were finely sanded and polished to minimize the risk. Durability? Again, no problem in an age of new wood products designed to prolong the life of lumber exposed to the elements or in direct contact with the wet ground.
Yet there was a problem few recognized at the time. Widespread use of chemical preservatives in lumber for outdoor construction posed a health risk to those in direct contact with it. Most wood marketed for play structures, decks and patios, picnic tables, waterfront docks, and walkways was factory pressure-treated with a preservative compound containing high levels of cancer-causing arsenic.
By 2002, chromated copper arsenate (CCA), by far the most popular preservative in pressure-treated lumber, had become a high-profile environmental news story, mainly through concerns voiced by groups of parents and community leaders suddenly aware of a new public health threat. Tests found arsenic present at alarming levels on contact surfaces of play structures and decks as well as in the surrounding soil. Public concern for the safety of children exposed to arsenic while playing was matched by concern for workers who handle this lumber regularly and inhale its dust from saw cuts and sanding. More than a few carpenters used it only reluctantly, and then only with masks and other protective clothing.
After years of testing, risk assessment, and reevaluation of CCA, the U.S. Environmental Protection Agency (EPA) announced in December 2003 that it will no longer permit CCA products to be used for residential and public space construction. The agency stopped short of offering help in solving clean-up issues for tainted sites or local dumps saddled with discarded CCA-treated lumber.
Well before the EPA decision, Leathers and Associates, designers of so many wooden playground structures over the years, voluntarily discontinued use of CCA-treated lumber in its construction projects, turning instead to other, apparently less toxic, chemical treatments and to plastic wood compounds.
Pursuing alternatives to pressure-treated lumber now seems not just a worthy goal, but an imperative.
The lumber industry uses a pressure-treatment process in which chemicals are carried into the wood by a liquid under intense pressure. Whether the compound is creosote (as in railroad ties and telephone poles) or CCA and its modern relatives, the chemical works by killing the organisms that attack the wood. The lumber of choice for pressure treatment is southern yellow pine, as it absorbs the chemicals better than other woods. Chances are, if you built a deck or porch on your house any time between 1974 and 2004 and bought the wood for it from a standard lumberyard, you used yellow pine treated with CCA.
In addition to the health risks associated with direct contact with CCA-treated lumber, there are disposal problems. The reason arsenic turned up in soil tests near the playground structures in Ithaca and elsewhere is that it leached into the soil, something that has certainly occurred and will continue to occur in landfill sites. Burning CCA-treated lumber is discouraged, as arsenic concentration in the resulting ash would make it extremely toxic and expensive to remove. Just how to deal with the looming problem of CCA waste is now a topic for discussion in state and federal environmental agencies across the country.
With CCA no longer available for most construction and consumers still hungry for rot- and insect-resistant lumber, new EPA-approved chemical combinations have been developed for pressure treatment. Chief among these new compounds is ACQ or copper quat, a mixture of copper and a quaternary ammonium compound. As in CCA-treated lumber, ACQ acts as a biocide, though the chemicals are not as powerful and therefore not as effective as CCA. Quat is a fairly common compound found in disinfectants and cleaners. The EPA so far has no reason to question use of ACQ-treated lumber in most construction where the wood is in contact with the elements or in ground contact, but because it is toxic to marine life, ACQ is not recommended for freshwater or marine use. Finally, both the EPA and the lumber industry recommend that builders use the same precautions in handling the new material as they did with CCA (that is, wear protective gear and wash hands frequently).
ACQ pressure-treated southern yellow pine is now the industry standard for outdoor construction. Lacking arsenic, it is unquestionably a safer product than the old CCA and is more easily disposed of in landfills. Still, it is highly corrosive, as carpenters know who have ignored the recommendations and chosen not to use double-dipped galvanized or stainless steel nails and screws, only to see them eaten away. Anecdotal evidence of rashes and respiratory problems among builders and lumberyard workers tends to underscore the point that, as one yard worker in Auburn, New York, put it, “You have to know that, if they’re using so many chemicals to change the nature of the wood, you’d better be careful messing with it.”
The building materials industry has developed a recycled plastic lumber that effectively replaces pressure-treated wood in all but structural applications, but although it resembles wood, many people object to it because it just isn’t the real thing. Alternative organic treatments can prolong the life of lumber used in outdoor construction, but none can equal the durability of pressure-treated wood.
Generally lost in the industry’s pursuit of new materials to replace CCA pressure-treated lumber is serious consideration of alternative, untreated wood – wood with naturally occurring density, strength, and resistance to rot. American chestnut (sadly all but gone from northeastern forests), cedar, cypress, and redwood are all examples of tough trees with naturally rot-resistant woods. Cedar and chestnut, for example, for many years provided the lumber of choice for ground-contact construction in the Northeast. Some cedar fence posts sunk in the ground two generations ago are still serving their purpose today. Native cedar is available in some locales, but West Coast cedar and redwood are expensive substitutes.
Dave Gell of Trumansburg, in the Finger Lakes region of New York, has what he is confident is a better idea, an alternative to pressure-treated lumber that appeals to the naturalist and forest lover in all of us. A logger, woodworker, and environmentalist, Gell has for many years worked with black locust (Robinia pseudoacacia), seeking to persuade people that this fast-growing, sturdy, and naturally rot-resistant tree has most, if not all, of the characteristics we look for in construction typically made with pressure-treated lumber.
A pioneer species, black locust quickly takes advantage of disturbances such as fire and abandoned farm fields. It grows well in a variety of soil types but prospers best in drained limestone soil, making it ideal for most of New York state outside of the Adirondacks. Farmers in eighteenth-century New York brought black locust trees north for fence posts, windbreaks, and erosion control along streams, and the trees quickly established themselves throughout, now often in pure stands.
According to Rene H. Germain, a forester and an associate professor at the State University of New York College of Environmental Science and Forestry in Syracuse, black locust is a tree to take seriously. “Few, if any, trees come close to its wood property ratings in bending strength, compression, hardness, stiffness, and resistance to decay,” he said. “The only other northeastern species with rot-resistant characteristics that come close are the eastern redcedar and northern white-cedar. However, both rate poorly in bending strength, compression, hardness, and stiffness. Bottom line: no northeastern tree comes close to black locust for ground construction.”
The species’ durability comes largely from flavonoids and condensed tannins, chemicals that are produced naturally in the growth process and protect the tree from rot. Black locust lumber also shows a high degree of resistance to termite and carpenter ant infestations. Living trees, however, can be plagued by two pests in particular. Best known of these pests is the locust leaf-miner (Odontata dorsalis), which feeds on leaf tissue, turning the tree crown brown. In years of abundance, leaf-miners can defoliate trees, but they are generally not considered lethal. The black locust’s most dangerous enemy is the black locust borer (Megacyllene robiniae), the larvae of which tunnel their way into the wood, weakening the tree, and eventually exposing it to the ravages of a fungus transmitted by the borer. Germain sees the borer as “the biggest obstacle facing black locust management. It is not a trivial problem.”
One variant of Robinia, the rectissima or shipmast locust, is of particular interest to Dave Gell, who describes it as a “super-tree – everything the common black locust has, only more.” A native of Virginia, the tall and rigidly straight shipmast locust was imported to Long Island and the Hudson Valley. From there it has since spread to locations in central New York, notably the Finger Lakes region. The tree was not, in fact, used for ship masts but for ribs and planking, where the hardness of the wood gave it an advantage even over traditional oak. Commonly reaching 100 feet, its size and straightness make it an excellent timber tree, yielding more useable board feet than standard black locust.
Gell started the Black Locust Initiative (BLI) in 1996 in response to a local teacher’s proposal that schoolchildren learn skills in arithmetic, graphing, biology, and general ecology principles through hands-on work in the woods. Since then, the BLI has established regular programs and workshops that introduce people of all ages to forestry and forest management techniques, with black locust as the focal point.
Pacing around a paper-crowded table outside his modest home in the middle of a dense woodlot, Gell ticked off the main reasons he has become interested in promoting shipmast locust as a tree ripe for timber management:
a fast grower, gaining more than 4 feet in height per year on good sites.
One idea Gell is actively pursuing these days is turning acres of conifer plantations in the Finger Lakes into nurseries for shipmast locust and other hardwood species. The plantations were created in the late 1920s and early 1930s as part of a state-government plan to reclaim old agricultural land for timber production and watershed protection. Now the rows of mature spruce and pine stand largely abandoned, not worth the cost of harvesting. As nursery sites for fast-growing trees like shipmast locust and catalpa, mixed with slower hardwoods like red oak and white oak, Gell believes these plantation could evolve into healthy, diverse forests with trees of different growth stages that are harvested in a sort of crop rotation. He calls this approach to growing and managing timber “progressive forestry,” and he spent part of 2004 working with a group of students on just such a nursery site in the Finger Lakes. Funding for this pioneer project came from a Sustainable Agricultural Research and Education grant from the U.S. Department of Agriculture.
“The biomass is already there, and thermal and moisture issues have already been solved for good growing conditions on healthy soil,” Gell explains. “It’s a low-value timber site at the moment, so a cost-benefit analysis favors using these forests as nursery places for a more valuable timber tree.”
But Gell is not concerned with timber industry economics in any numbers-crunching sense. Rather, the economic calculus of the BLI focuses more on the value of environmental stewardship and community needs. The BLI has even developed an invoice for their projects that contains a bottom line for “green accounting,” a measure of environmental benefits offsetting the dollar value of the work done.
To Gell, his most important work is reaching out to children who will be future stewards of the forests. BLI board member Carl Leopold, son of pioneering ecologist Aldo Leopold and himself a passionate environmentalist, has been an admirer of Gell’s for many years. “The big promise of the initiative is that it reaches kids, and they get just taken away by the great fun of it all,” he said. “Dave Gell has a lot of support from the schools in the community, and it’s just great that the kids can learn in such a constructive and ecologically sensitive environment.”
“You might have a kid in the fourth grade who plants a black locust with his class,” Gell mused. “In 30 years it’s going to be a 70-foot timber tree. He can say later, when he’s a member of the school board or a parent of school-aged kids, that he planted that tree that they can now use to build a playground. It’s a tree that can bridge the generations.”
It’s also a tree that may eventually provide a natural alternative to toxic pressure-treated lumber. Whether or not it will be grown in industrial quantities has yet to be seen, but the first steps toward that goal have been taken.
Eben McLane is a New
Hampshire native who currently lives and writes in the Finger Lakes region
of New York. Source
Contact : firstname.lastname@example.org
Copyright : © acacia-robinier 2009 www.acacia-robinier.be
Le robinier ou faux acacia du nom de Jean Robin, botaniste et arboriste du roi Henri IV, présent en France et susceptible de remplacer les bois exotiques d'importation. Il est imputrescible, la présence d'une sorte d'antiseptique naturel, le “robinetin”, qui lui permet de résister aux attaques des parasites (insectes et champignons). Classe de risque sans aucun traitement chimique : 4. AKATZ
Le robinier peut être produit en forêt cultivée, même dans les sols sablonneux. Sa croissance est très rapide puisqu'il est exploitable en bois d'oeuvre une vingtaine d'années après sa plantation. Les coupes d'éclaircies peuvent fournir des piquets et du bois de chauffage.
Autre particularité : le robinier fait partie d'une catégorie de plantes intégrée à la famille des légumineuses, lesquelles sont dotées d'un système de symbiose racinaire avec nodules utilisant l'azote de l'air. C'est ce qui permet aux Hongrois de cultiver à bon compte des légumes dans les interlignes. Le robinier présente aussi une exceptionnelle capacité à absorber le Co2.
Cet arbre, importé d'Amérique du Nord en France au XVII è siècle et très apprécié jusqu’au Second Empire pour ses qualités physiques et sa durabilité naturelle, s’étend sur près de 18.500 hectares en Aquitaine, dont 8.600 ha en Gironde. Son bois, aujourd’hui issu de forêts “cultivées”, n’était jusqu’alors réservé qu’à la confection de piquets de vignes.
Naturellement résistant aux agressions extérieures, le robinier appartient à la catégorie des bois durs. Il résiste aux attaques des insectes destructeurs, aux champignons parasitaires les plus fréquents dans nos climats tempérés, aux intempéries et s’affirme comme un matériau particulièrement adapté aux ouvrages extérieurs soumis à des humidifications fréquentes ou permanentes.
Ses qualités fonctionnelles (antidérapant, jamais
brûlant après exposition au soleil, sécuritaire pour les
enfants en cas de choc et facilement réparable au besoin) et esthétiques
(le bois de robinier prend une jolie teinte brune aux reflets dorés comparable
au teck), ses avantages économiques incontestables, son aspect noble
et naturel, lui confèrent à la fois simplicité et élégance.
Avec des caractéristiques équivalentes, il constitue ainsi une
réelle alternative à l’utilisation des bois tropicaux les
plus prisés, aussi bien adapté aux équipements extérieurs
collectifs qu’au confort douillet des aménagements de jardins particuliers.
salon bois et habitat 2010 liste des exposants de l exposition bois et habitat en belgique horaires bois et habitat namur parking boiset habiat
acasia acaccia aquasia accacia acassia robinnier robiner robinia robynier akac akacz akatz akasia akacia bardage cèdre bardage alternative au cèdre en bardage mural ganivelles en robinier tornado ursus grillage pour clotures en acier galvanisé cloture ecologique
English: black locust
German: falsche Akazie
French: robinier, faux acacia
Russian: belaya akatsiya
Dalle en bois 50cm 50 cm dalles en bois de robinier 60 60 cm
caillebotis cailleboti calieboti cailleboti dalle prefabriqueé préfabriqée
en robinier, dalle 50 50 en robinier pour terrasse sur plots , terrasse avec
dalles d'acacia 50 50 cm
Due to its natural durability, Robinia can be used for outdoor purposes - including fences - without any special chemical treatment. It is common that vertical pales simply planed or decorated with shaping are fixed onto a metal or wood frame. Planking timbers with planed surface but unedged also are used frequently to construct fences. There are other various options for fences from Robinia wood.
Robinia is hard and wear-resistant wood therefore is especially suitable to manufacture parquet. It is used to manufacture grooved parquet, which has to be surfaced and varnished after inlaying. At the same time it is used to make the covering layer for the two- and three-layered prefabricated parquet. The prefabricated parquet can be used immediately after inlaying because in the manufacturing procedure it is ground to ready and varnish is applied in some layers. Due to its dark colour the steamed Robinia wood provides very special appearance to the product.
Landscaping materials and Playground equipment
It is very popular in the landscape architecture, too. It is used for short supporting wall, bordering the planting beds and pavement in the gardens.
Playground toys are made of wood preferably. An important advantage of Robinia is its long durability without any chemical treatment. Rods and support elements in the playground can be manufactured from material shaped to cylinder-shape but the natural forms are also very popular.
Sawnwood, friezes, slats
Goods from sawmills: unedged and edged sawn goods, semi-prefabricated parquet and furniture products, e.g. parquet friezes and slats. There are drying chambers in most of the sawmills. In certain places the Robinia wood is treated with steam. As an effect of the steaming - depending on intensity and time - the Robinia wood gets dark brown or very dark brown.
Vineprop and -sticks, pole, stake
Since it widely is used in Europe Robinia wood has been applied mainly for making vineprops and stakes. It can easily be split with cleaving-axe and other equipment. When sticks are fixed in the soil next to the vine-plants and contact with the soil they are durable for 25-45 years without any chemical treatment. Today the vine-props and sticks are made with sawing machine.
For vine-prop and hydraulic construction purposes the thick rods and posts can be applied without any special processing.
Sanded poles, poles without sapwood and turned poles are mainly used in landscape architecture but at other construction fields as well.
avivés en robinier grumes plots non sechés brut de sciage,bois d'oeuvre,clayonnage,construction de berges,bords d'etangs ,platelage,plattellage,platellage
Wood is used for heating and cooking since the ancient time. Today a lot of houses and apartments are heated with wood. The popular fireplaces provide nice warm as well as very good atmosphere. Robinia gives firewood of very good quality: it can easily be split and burst into flame. It is prepared in one-meter long pieces or split to size putting into the fireplace. For practical transport unit packages of Robinia firewood are made.
En raison de sa durabilité naturelle, Robinia peuvent être utilisés pour fins de plein air - y compris les clôtures - sans aucun traitement chimique. Il est courant que vertical pâlit rabotés ou simplement décorées avec façonnage sont fixés sur une ossature de bois ou de métal. Planches de bois rabotés de surface mais aussi unedged sont fréquemment utilisés pour construire des clôtures. Il existe d'autres options différentes pour les clôtures de bois Robinia.
Robinia est dur et résistant à l'usure du bois est donc particulièrement adapté pour la fabrication de parquet. Il est utilisé pour la fabrication des rainures du parquet, qui doit être refait surface après la marqueterie et vernis. En même temps, il est utilisé pour faire la couche de recouvrement pour les deux ou trois couches préfabriquées parquet. Le parquet préfabriqués peuvent être utilisées immédiatement après l'insertion parce que dans le procédé de fabrication, il est prêt à terre et de vernis est appliquée dans certaines couches. Grâce à sa couleur foncée et de la vapeur Robinia bois offre très spéciale à l'apparence du produit.
L'aménagement paysager des matériaux et équipements
Il est très populaire dans l'architecture de paysage, aussi. Il est utilisé pour de courtes mur de soutènement, en bordure de la chaussée et les lits de plantation dans les jardins.
Aire de jeux jouets sont faits de bois de préférence. Un avantage important de Robinia est sa longue durée de vie sans traitement chimique. Cylindres et les éléments de soutien, dans l'aire de jeu peut être fabriqué à partir d'un matériau en forme de la bouteille en forme de formes naturelles, mais le sont aussi très populaires.
Bois de sciage, frises, des becs
Les marchandises en provenance des scieries: unedged et tranchant sciage, semi-préfabriqués parquet et des meubles des produits, par exemple, frises de parquet et lamelles. Il ya des chambres de séchage dans la plupart des scieries. En certains endroits Robinia le bois est traité à la vapeur. Comme un effet de la vapeur - en fonction de l'intensité et de temps - le Robinia bois est brun foncé ou brun très foncé.
Vineprop et de bâtons, de pôle, participation
Comme il est largement utilisé en Europe Robinia bois a été appliquée essentiellement pour la fabrication vineprops et des enjeux. Il peut être facilement partagés avec clivage-hache et d'autres équipements. Lorsque les bâtons sont fixés dans le sol à côté de la vigne, les plantes et le contact avec le sol, ils sont durables pour les 25-45 ans, sans aucun traitement chimique. Aujourd'hui, la vigne, les accessoires et les bâtonnets sont fabriqués avec des machines de sciage.
Pour la vigne et la proposition de construction hydraulique de l'épaisseur des tiges et des postes peut être appliqué sans un traitement spécial.
Poncé poteaux, des poteaux sans aubier et se pôles sont principalement utilisés dans l'architecture de paysage, mais à la construction d'autres domaines.
Bois de chauffage
Le bois est utilisé pour le chauffage et la cuisine depuis l'ancien temps. Aujourd'hui, beaucoup de maisons et d'appartements sont chauffés au bois. Le populaire cheminées fournir agréable ainsi que de très bonne ambiance. Robinia donne bois de chauffage de très bonne qualité: il peut facilement être divisé et pris feu. Il est préparé dans un mètre de long ou de séparation de pièces à mettre en taille de la cheminée. Pour des raisons pratiques de transport de paquets de bois de chauffage Robinia sont faites.
Bacs à fleurs et jardinières
Bois ronds tournés
Avivés brut de sciageRobinier: Le meilleur bois de coeur d'une production transparente.