Regionalised Life Cycle Assessment of Bio-Based Materials in Construction; the Case of Hemp Shiv Treated with Sol-Gel Coatings

Ben Amor,Pierre Blanchet,Mohammad Davoud Heidari,Michael Lawrence

doi:10.3390/ma12182987

Abstract

Interest in intrinsically low-energy construction materials is becoming mainstream, and bio-based materials form a key part of that group of materials. The goal of this study was to analyse the environmental impact of applying a sol-gel coating on hemp shiv, in order to improve the durability of this innovative bio-based material, using a regionalised LCA model, taking into account regional specific peculiarities. This study analysed the environmental performance of using bio-based materials in the building envelope compared with traditional synthetic construction materials, and compared the impact of a regionalised approach with a global approach. The carbon footprint of treated hemp shiv in a wall with a U-value of 0.15 W/m2.K was compared to untreated hempcrete and a reference cavity wall with the same U-value. Considering the environmental damage caused by the production of hemp shiv, nitrogen fertiliser was the hotspot. The LCA results showed that, using innovative bio-based materials in construction, treated hemp shiv with sol-gel can decrease the carbon footprint of a building envelope through carbon sequestration. Using the more accurate site-specific information in life cycle inventory and impact assessment methods will result in more consistent and site-appropriate environmental results for decision-making.

Highlights

The construction sector has a vast environmental impact and, this sector is responsible for producing a huge amount of CO2 emissions, for example, the building sector accounts for around40% of the total emissions in the UK [1]
Innovative bio-based materials such as hemp shiv are being developed for use in construction, with the goal of being more environmentally friendly during their life cycle
The second step of an Life cycle assessment (LCA) study is a life cycle inventory (LCI), where data for all processes are collected according to the functional unit (FU)

Summary

Introduction

The construction sector has a vast environmental impact and, this sector is responsible for producing a huge amount of CO2 emissions, for example, the building sector accounts for around40% of the total emissions in the UK [1]. Choosing materials with a high impact on the environment and energy consumption would increase the total environmental loads of a building. Innovative bio-based materials (materials produced from biomass) such as hemp shiv are being developed for use in construction, with the goal of being more environmentally friendly during their life cycle. Since hemp shiv has a highly porous structure, in the very first minutes of exposure it can absorb a large amount of water [2]. This hydrophilic nature of hemp shiv makes it potentially a less durable material because of the risk of colonial fungal growth

Objectives

Methods

Results