Measurement and study of the evolution of effective thermal conductivity within the straw material

Written by esba

The eco-materials increasingly used in construction are generally valued through the coupling between their mechanical and thermal properties. While thermal properties may be the primary characteristics in the case of insulation panels inserted into structures, the coupling of thermal conductivity and mechanical strength is inseparable in the case of materials used in the structure of the building. In all cases, the thermal conductivity of the material is inversely related to its density once it is in place.
Straw building projects tend to change the role of straw bales from that of a simple insulator to that of a supporting and insulating element.

The objective of this service is to characterise changes in the thermal conductivity of straw bales according to their state of compaction. The client is the company Bois et Paille. The approach consists of :

  • Receiving compacted bales at different densities, determining their density and water content
  • Measuring the effective thermal conductivity of each bundle in at least two orthogonal directions
  • Understand the relationships between the effective thermal conductivity and the densities of the bundles as a whole.

Author: Eddy FRUCHARD


About the author


The European Straw Building Association is an independent European association, devoid of any profit making motive. The object of the Association is to promote and develop the use of straw, as a sustainable way of building in all the senses of the term “sustainable”: renewable, ecological, healthy, energy and climate efficient, social and economic.
The Association is a federation composed of organisations and people particularly concerned with the use of straw in buildings.