Numerical modeling of a hemp-lime blocks wall subject to horizontal in-plane loads

Hemp-lime is one of the nature-based solutions developed since the early 2000s to reduce the huge environmental impact of the building sector; it is produced mixing lime with hemp shives produced by the scutching of industrial hemp plants. The production of such material determines the recovery and enhancement of by-products of agricultural cultivation in accordance with the principles of circular economy. Hemp-lime is a carbon negative material mainly due to the utilization of vegetal aggregates and to the carbonation reaction, characteristic of lime, through which carbon dioxide sequestration takes place. In this research, the behavior of a wall built in prefabricated hemp-lime blocks has been investigated focusing on the mortar joints and on the determination of their eventual seismic and wind bracing contribution in a building. Starting from the determination of mechanical properties of the blocks, a finite element numerical analysis of the hemp-lime wall system has been developed. The results show that mortar joints exert a stiffening action in a hemp-lime system as opposite to other building techniques where joints are generally weak parts. Although the mechanical properties of the hemp-lime wall are generally less performing than those offered by a traditional wall (brick, stone) the bracing effect is appreciable for residential buildings in moderate seismicity areas due to the reduction of stress states in the load-bearing elements as frame or pillars.