Sustainable building material is still a hot topic in industry and research. As our world’s population continues to grow, sustainability will become even more critical in coming years. Let’s take a look at one of the more promising sustainable building materials – engineered bamboo.
What Is Engineered Bamboo?
Engineered bamboo is simply bamboo culm that has been processed and mixed with a laminated composite. Bamboo culm is the ringed stem of the bamboo plant. The process and end result are very similar to glue-laminated timber products.
What Are the Benefits and Drawbacks?
Engineered bamboo seems to have many of the same advantages as natural bamboo. Its rapidly renewable, cost-effective, and ecologically friendly thanks to its faster growth rate.
In many ways, natural bamboo is similar to timber. The strength and capabilities make it perfect for replacing timber. Since it has four times the carbon density of spruce forests, it is much more compactly grown than timber. This reduces the space needed to produce. It is considered to be highly resistant to mildew and fungi.
However natural bamboo has some drawbacks. The engineering data is lacking and building codes need to be developed. This has limited its use to cosmetic only, not structural.
It’s also limited in its variability. It isn’t as uniform as timber. That makes it harder to market as a reliable product. The round shape of the bamboo culm makes it hard to make connections and joints.
Engineered bamboo is designed to retain many of the same advantages of natural bamboo while mitigating the drawbacks.
It has the same strength and sustainability of bamboo but is engineered to have less variability than natural bamboo. By turning natural bamboo into more standardized sections, a more reliable and sellable product is available.
What Are Its Uses?
Engineered Bamboo has many applications in construction. Two products have been developed so far: bamboo scrimber and laminated bamboo sheets.
Bamboo scrimber, also called strand woven or parallel strand bamboo, is created by saturating crushed fiber bunders in resin and press them into a dense block.
This procedure is highly efficient. It uses about 80% of the raw bamboo.
Because the bamboo fibers are separated but not cut, the longitudinal direction retains the same properties as natural bamboo. The resin holds together the fiber bundles, which mimics the strength of the natural bamboo in the latitudinal direction.
This is typically used outdoors – as deck flooring or as a skin for buildings. The product is described as looking similar to mahogany. However, research has been looking into using bamboo scrimber as a structural material. In 2009, Wei et al. built a 2 story house using scrimber to demonstrate its success as a structural material.
The other product, laminated bamboo sheets, is significantly less efficient to produce. Only 30% of the raw material is used.
To make laminated bamboo sheets, the bamboo culm is first split, planed, and processed (bleached or caramelized). This is where 70% of the natural bamboo is lost. Next, the processed culm is laminated and pressed to form the board product.
The board product is glued together with the board product fibers going in different and random directions. This process is similar to how plywood is produced. The different directions of the bamboo fibers allows for increased strength in all directions.
This product is limited to indoors use and furniture surface applications. Just like with bamboo scrimber, structural uses are being researched and developed.