A plant fibre traditionally used by ancient Egyptians to make rope and sailcloth is now finding uses as a component in structural building materials.

Image: Na9234

Kenaf (Hibiscus cannabinus), a versatile, quick-maturing, fibrous plant of the jute family, was first planted in Egypt about 3,000 years ago. It now grows on four continents, and researchers at Malaysia’s Universiti Teknologi MARA (UiTM) are finding a host of new cutting-edge applications, including soundproofing, thermal insulation and a sturdy, low-maintenance plastic-wood composite that forms a strong structural building material.

Historical uses for kenaf range from rope and sailcloth on ancient Nile boats to clothing, heart-friendly cooking oils and, starting last year, interior door panels in some Ford vehicles.

Now civil engineering researchers at UiTM have added kenaf fibre to masonry to create sand-cement kenaf blocks, which offer better sound and thermal insulating properties than standard concrete blocks. Since Malaysian tropical buildings feature single-wall construction, insulation that does not add an extra layer is more practical. A bonus is that where traditional insulations use inorganic fibres that are known to be harmful to human health, natural kenaf fibre appears to be a safer additive.

In another project, a second UiTM team has developed a kenaf-based wood-plastic composite (WPC), for structural uses such as joists and rafters. Their product promises low maintenance, durability and resistance to termites and other insect attacks.

The researchers say that fibre from the fast-growing kenaf plant shows excellent promise as a replacement for traditional sawdust fillers, which are becoming scarcer and more costly. What’s more, when kenaf is mixed with a plastic binder in higher proportions than sawdust, the resulting material is as strong or stronger than current sawdust-based structural products, while using less plastic binder. This makes it a more cost-effective and environmentally sustainable product.

The researchers recommend further testing to confirm the mechanical properties of this product. But based on the strength of testing to-date, they believe the data reinforces the case for commercializing WPCs with higher kenaf content.

 

 

For further information contact:

Sand-cement kenaf blocks
Kartini Kamaruddin
Faculty of Civil Engineering
Universiti Teknologi MARA
Malaysia
Email: ce_kartini2002@yahoo.com

Wood-plastic composite

Aruan Effendy Mohd Ghazali
Faculty of Civil Engineering
Universiti Teknologi MARA
Malaysia
Email: aruan624@salam.uitm.edu.my