No abstract

Inclusion of fibres in soil blocks has been shown to enhance strength development. This study investigates the effect of aspect ratio of coconut, bagasse and oil palm fibres on the mechanical properties of soil blocks. Experiments were conducted on soil blocks with fibre aspect ratios (25-125) to determine the compressive and tensile strength of the blocks. Blocks with coconut and oil palm fibres showed increasing strength with increase aspect ratio, while bagasse fibres showed an initial increase followed by a decline at higher aspect ratio. The study concludes that generally longer aspect ratios produce better mechanical properties of soil blocks.

Several studies have focused on improving the properties of soil blocks/bricks due to perceived and real strength and durability limitations. A review of 56 published studies is presented on the effect of stabilization on the performance characteristics of soil blocks. The review found that few studies have been conducted on durability properties of enhanced soil blocks as compared with physico-mechanical properties. Fibre-enhanced soil blocks tended to have peak performance with an optimal content that achieved maximum performance. The maximum performance improvement was generally less than a doubling of the strength of the soil without the fibres. Binders showed a continual improvement with greater concentrations, so much greater improvements can be obtained if the economic and social costs can be justified. Both fibres and binders have variable performance on water absorption with both reductions and increases possible. Generally, both fibre and binder inclusion in soil blocks enhance the performance characteristics of the blocks. Binders are typically more effective on a mass-fraction basis.However the supply of fibres is usually at a lower cost and a reduced environmental impact, and therefore may have a better performance on a per-cost or per-impact basis.