A holistic sustainability overview of hemp as building and highway construction materials

The construction sector, responsible for over one-third of global carbon emissions, is increasingly focusing on hemp-based construction materials to alleviate the environmental impact in the built environment; however, the lack of information and streamlined processes hinder widespread adoption. By conducting a comprehensive review of state-of-the-art research, this study explores the vast potential of hemp-based materials across the built environment, encompassing building and transportation applications. In this study, the material properties and application of hemp lime concrete for buildings, along with hemp fibre in asphalt for highways, are discussed, and crucial research gaps and technical challenges are identified. Employing a holistic sustainability approach, the material evaluation considers economic, social, and environmental factors. Notable hemp construction projects are presented as case studies, emphasising their environmental carbon credentials. Furthermore, technoeconomic challenges are scrutinised, and effective solutions are proposed. Beyond its role as a wall material, hempcrete's significant application as building insulation material is highlighted due to its exceptional hygrothermal properties. The material also shows promise in enhancing asphalt mix for pavement construction. Evidence from life cycle analysis supports the claim that hempcrete can be considered a carbon-negative material. Moreover, the findings indicate that the hempcrete industry has the potential to yield various macroeconomic and socio-economic advantages, including job creation, enhancing energy access, alleviating cost of energy, and improved societal health and well-being.