LIME AND HEMP CONCRETE LCA: A DYNAMIC APPROACH OF GHG EMISSIONS AND CAPTURE

Author(s): T. Lecompte, A Levasseur, D Maxime
Paper category: Proceedings
Book title: Proceedings of the 2nd International Conference
on Bio-Based Building Materials
Editor(s): Sofiane AMZIANE, Mohammed SONEBI and Karine CHARLET
ISBN:
e-ISBN: 978-2-35158-192-6
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 533-541
Total Pages: 8
Language : English

Abstract: Lime and hemp concretes are well known and studied as low-impact materials for building.
During the last two decades, a few studies have shown their interest in terms of environmental
impacts such as embodied energy, air pollution or GHG emissions. On the other hand, new
carbon footprint calculation methods were proposed to assess the value of temporarily storing
carbon in long-lived products such as building structures and insulation. This is an important
aspect for bio-based materials, as they capture and store carbon. From an environmental point
of view, it would be of interest that GHG emissions due to cultivation, manufacturing,
transportation, construction, demolition and end-of-life could be compensated by the beneficial
effect of a long-term carbon storage. The principal aim of this study is to evaluate the long-term
effect on climate change of using LHC in building. GHG emissions and uptakes were assessed
using a dynamic life cycle assessment approach for several scenarios: 1) different cultivation
practices for hemp (in the French context, surveys of 2014-2015 provided by the Cetiom), and
2) different mixes and formulations for the LHC, i.e. two classical ones: sprayed and cast LHC,
and a more innovative one: compacted LHC. Whatever the formulation, a woody structural
frame is necessary, composed of local timber wood (less than 100km from construction site). To
take into account the emission dynamics, plants growing (trees and hemp) and carbonation of
lime into the walls were considered. Optimum scenarios were compared, by taking the minimum
and maximum impact for each mixes (different cultivation practices, transportation of lime and
hemp, end-of-life scenarios). As a result, some LHC with high hemp/lime ratio, low-impact crop
practices, and a proper end-of-life scenario could be a solution to stock carbon and keep a
positive effect on climate, even on the long-term (more than 100 years).

Online publication :2017
Publication type :full_text
Public price (Euros) : 0.00