Prospective Materials for Building Construction in Hot Countries: The Case of Straw Blocks

The use of plant-based materials represents a significant shift in construction practices, contributing to the achievement of Sustainable Development Goals 9 and 11. However, materials such as straw bales typically exhibit low compressive strength and significant displacement under compressive loads. To date, limited efforts have been made to improve the performance of straw bales. This study aimed to develop an alternative material, known as straw blocks, and assess their potential as a viable building material.

The manufacturing process of straw blocks involved preparing the binder and producing the blocks from straw. The water resistance, thermal resistance, and compressive strength of the blocks were measured, along with the structural performance of the straw block walls.

The average compressive strength and thermal conductivity were recorded as 1.25 MPa and 0.06 W/m·K, respectively. The initial rate of water absorption ranged from 0.10 to 0.22 g/in²/min. Furthermore, plastered straw block assemblies withstood a uniformly distributed load of 286 kN/m².

The recorded compressive strength of straw block is 62 times greater than the published compressive strength of straw bale (0.02MPa). Although the value seems insignificant, the load-carrying capacity of a plastered straw block wall is higher than the minimum slab load, which is 18.2 kN/m² for residential buildings.

According to the data above, the straw block is a conducive and promising building material for climate change adaptation. The small thermal conductivity obtained will improve the overall indoor thermal comfort. Straw block can be used for the construction of one-storey buildings and partition walls in multi-storey buildings.