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.

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Background: The negative impacts of the construction industry are compelling arguments for embracing technology that contributes to carbon footprint reduction and resources conservation. Toward the achievement of objective 9 of the Sustainable Development Goals, the development of new building’s materials like straw bale has advanced in the construction industry. As demonstrated in the literature, straw bale is an eco-friendly material that presents many advantages, like its contribution towards a circular economy. However, it has low compressive strength and displays high displacement under compression load. So far, no attempt has been made in order to enhance the strength of straw bales. Objective: This study aimed to develop alternative material to straw bale using chopped straw stems mixed with a binder (gum Arabic) and determine its stress-strain characteristic. Methods: The manufacturing process of the new material involved the use of chopped straw and gum Arabic to form straw blocks. Results: Results obtained show that the compressive strength of straw block (1.25MPa) is greater than the strength of straw bale (0.02MPa). Also, the average displacement recorded during compression load on straw blocks (29mm) was 2.8 times smaller than the displacement in straw bale (80mm). In terms of shape and size, straw blocks match with conventional materials like cement or compressed block. This will facilitate their use in construction compared to straw bales that require skilled laborers for pre-compression and plastering. Conclusion: The use of gum arabic helps in holding straw stems together and forms a compact material with improved strength compared to straw bale. Performance improvement of the characteristics of load-bearing straw bale walls can be addressed by using straw blocks.

The use of conventional building materials is facing two main challenges of excessive cost and large-scale depletion of the sources thus creating environmental problems. These challenges demand that alternative building materials be explored that are not only affordable but are also environmentally friendly. In this regard and inspired by the global need for sustainable development, earth(soil) is re-emerging as the grand eco-material for building construction due to its availability, environmental/cultural appropriateness, structural adequacy, familiarity to the local people, "breathability", health benefits, amongst others. This paper presents results of experimental work in Kenya aimed at utilizing earth in formal housing constructions with a view to alleviating the severe housing shortage in the country. Studies were conducted on structural performance of various types and blends of earth material, from which a suitable blend was selected and used to construct a model two-storey rammed earth building. The model house had load-bearing walls of rammed earth, and a hollow-pot reinforced concrete slab containing light-weight stabilized soil blocks. The rammed earth two-storey model house was tested for vertical load resistance using sacks of sand. Results obtained from this study indicate that certain blends of local earth materials had higher stabilized block strengths than the standard dressed stones which are normally used in construction in Kenya. Further, the model ecohouse was able to resist applied vertical loading with minimal deflections within the standard requirements. The model house has been in use as an office building for over four years with negligible deterioration in terms of material erosion or cracking or deflections.