title: The influence of the type of lime on the hygric behaviour and bio-receptivity of hemp lime composites used for rendering applications in sustainable new construction and repair works.
abstract: The benefits of using sustainable building materials are linked not only to the adoption of manufacturing processes that entail reduced pollution, CO2 emissions and energy consumption, but also to the onset of improved performance in the building. In particular, hemp-lime composite shows low shrinkage and high thermal and acoustic insulating properties. However, this material also shows a great ability to absorb water, an aspect that can turn out to be negative for the long-term durability of the building. For this reason, the hygric properties of hemp-based composites need to be studied to ensure the correct use of this material in construction and repair works. The water absorption, drying and transpirability of hemp composites made with aerial (in the form of dry powder and putty) and hydraulic limes were investigated here and related to the microbial growth induced by the water movements within the material. Results show that hemp-natural hydraulic lime mixes exhibit the highest transpirability and drying rate, the lowest water absorption by immersion and capillary uptake and the least intense microbial attack and chromatic change. A microscopical study of the hemp shives also related their great ability to absorb water to the near-irreversible swelling of their structure under dry-wet conditions.
authors.affiliation: School of Geography and the Environment, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom.
authors.forename: Anna
authors.initials: A
authors.lastname: Arizzi
authors.affiliation: CANNABRIC, Cañada Ojeda, 8 E-18500 Guadíx, Granada, Spain.
authors.forename: Monika
authors.initials: M
authors.lastname: Brümmer
authors.affiliation: Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18002, Granada, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Martín-Sanchez
authors.affiliation: Departamento de Mineralogía y Petrología, Universidad de Granada, Avda. Fuentenueva s/n, 18002, Granada, Spain.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cultrone
authors.affiliation: School of Geography and the Environment, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom.
authors.forename: Heather
authors.initials: H
authors.lastname: Viles
mesh_terms: D000704:Analysis of Variance; D017610:Calcium Compounds / Q000737:chemistry; D002188:Cannabis / Q000737:chemistry*; D003247:Conservation of Natural Resources; D003252:Construction Materials / Q000382:microbiology; D059013:Microbial Consortia / Q000502:physiology; D010087:Oxides / Q000737:chemistry; D010539:Permeability; D014867:Water / Q000737:chemistry
chemical_list: D017610:Calcium Compounds; D010087:Oxides; D014867:Water; C016538:lime