Eco-Friendly Use of Guinea Corn Straw as Building Material in Construction for Sustainable Development

Abstract

Globally, million tonnes of straws are produced annually from farms as agricultural wastes. Walls made from plastered straw bale blocks are known to have low thermal conductivity and provide insulation for houses when used in building construction. In this study, the use of guinea corn straw encapsulated in cement mortar to produce masonry units for construction of building was carried out.The baled straws were manually compressed and tightly bound with twine purposely to avoid looseness, thus increasing the density of bale. Construction of wooden moulds of inner sizes of 150mm x 200mm x 400mm for straw brick blocks was adopted catering for mortar thickness of 50mm as cover for adequate protection of the baled straw encased. The average compressive strength of mortar used was determined, the density and strength of the resulting masonry units were also determined. A prototype building of plan dimension 5000 mm x 3000 mm was constructed with the use of straw brick blocks. The average compressive strength of the mortar was 11.11N/mm², the density and strength of the straw bale block was found to be 62.86 kg/m³ and 1.87N/mm² respectively. These values meet the minimum specification outlined in BS5628-1:1992 for masonry unit standard for building construction. The cost of producing a square meter of wall with straw block was compared with that of the conventional sandcrete block. The comparison showed that the use of straw block in wall construction reduced the cost of producing blocks by almost 35%.

Keywords: straw bale, straw block, compressive strength