Structural Performance of Straw Block Assemblies under Compression Load

Background: In recent decades, the enduring interest and continued development of straw bale as a walling material are based on its beneficial properties. Straw bale is a biomaterial that contributes greatly to carbon footprint reduction and offers excellent thermal insulation. It is proved that plastered straw bale assemblies have good mechanical properties and can be used for the construction of a single storey building. It is known that straw bale presents high displacement in the assemblies; thus, pre-compression is a major step that helps to push down straw bale so as to avoid future structural failure in the wall. There is no clue yet if this method is structurally beneficial than to stabilized single straw bales before assembling them into a structural panel. Objective: This paper presents the structural performance of straw block assemblies under compression loads. Method: Straw blocks and mortar were used to construct plastered and un-plastered wall panels, which were tested under uniformly distributed compression load till failure. Results: The results obtained show that plastered straw block assemblies can support at least 286 KN/m2, which is higher than the minimum slab load 18.25KN/m2, including imposed load for a residential house. In addition, the strength of plastered straw block assemblies plastered with cement-gum mortar, 0.3 N/ mm2 is greater than the strength of a single storey building (0.19N/mm2). Furthermore, results indicate that un-plastered and plastered straw block assemblies perform better than un-plastered and plastered straw bale assemblies. Plastered straw block assemblies support up to 52KN while plastered straw bale assemblies support only 41.1KN. Conclusion: Under compression load, straw block assemblies have a load carrying capacity greater than the minimum slab load. Therefore, Straw block can be used for the construction of a single storey building.