Characterisation of Hemp Shiv and its Effect on the Compressive Strength of Hemp Concrete

Hemp concrete is a promising product that has a wide range of properties and diversification. It is a sustainable material, with good thermal and acoustic properties. Being plant-based material, it has also the ability to absorb carbon dioxide, leading to significant reduction in carbon footprint. This paper investigates the role of hemp aggregate by characterising the hemp aggregate and testing the compressive strength of hemp concrete. The characterisation of hemp aggregate included testing its grading, water absorption and bulk density. Factors that affect the mechanical behaviour of hemp concrete were investigated, including water to lime (W/L) ratio, binder to hemp (B/H) ratio, pre-saturation of hemp and degree of compaction. Statistical models were derived to determine the significance of each factor and their interactions. Characterisation of hemp revealed that majority of hemp shiv retained between 1.18 to 3.35 mm sieve. The water absorption of hemp was approximately 300% after 48 h and bulk density was around 95.4 kg/m³. Models suggest that W/L and B/H were the most significant parameters affecting the compressive strength of hemp concrete.