Bio-Composite Development for Acoustic Barriers
An innovative biocomposite material utilizing reclaimed material and Saskatchewan crop residue is under development. This material is intended to not only minimize the societal, environmental footprint by using sustainable or reclaimed material, but also provide good acoustic and vibration damping and possess semi-structural, construction strength. This value-added product is to be designed into an acoustic barrier in construction areas or along traffic corridors. By varying the combination of natural fibres, such as flax or hemp fibres, with reclaimed polymers, such as polypropylene and rubber, a resilient material with ultimate strengths ranging from 3 to 5 MPa with the capacity to attenuate acoustic noise by 20 dB have been manufactured and evaluated by University of Regina researchers. These properties of good acoustic and vibration damping capacity and high strength essentially are inversely related with increased fiber content. Basically, an increase in fiber content tends to increase the damping capacity yet decrease the strength. Generally, a compromise between these competing properties of strength and damping can be achieved with 30 to 50% fiber concentration of the biocomposite. To improve the structural strength, the manufacturing processes of compression moulding and extrusion combined with compression moulding have been compared with the latter providing improved strength characteristics. Also, fiber processing prior to manufacturing affects strength, density, water absorptive and acoustic absorptive. Fundamental engineering design can be applied to further improved structural integrity and enhance the acoustic damping properties of the material to create a functional acoustic barrier along a traffic corridor.