Potential of fibre reinforced and cement stabilized fibre reinforced soil blocks as sustainable building units

The alarming pollution level and its consequences on the environment owing to the use of conventional building materials have resulted in a renewed interest in earth-based materials for construction. The soil used in the production of earth blocks requires a specific composition of granular and clay soil, which is of limited availability. This study attempts to use locally available granular soil with limited fines content for block making and investigates the choice of reinforcing soil blocks for optimal performance with minimum cement content. Natural fibres– areca, coir and flax were selected for reinforcing the soil blocks, and 2.5% cement was used for stabilizing the blocks. Fibre reinforcement improved the mechanical properties of the soil blocks, but their durability was limited. Coir-reinforced soil blocks showed an increase of 3.56 times in strength compared to unreinforced soil blocks at the optimum fibre content of 1%. Similarly, coir-reinforced cement stabilized blocks showed nearly 1.70 times strength improvement when compared to unreinforced cement-stabilized blocks. A minimal addition of 2.5% cement improved the durability properties like erosion resistance, linear shrinkage, water absorption and abrasion resistance of the blocks. Flax fibre-reinforced blocks showed better durability properties. The minimum quantity of cement improved both mechanical and durability properties qualifying the blocks for indoor and outdoor construction use, as observed from wallette tests.