Mechanical behavior of an assembly of wood–geopolymer

Mechanical behavior of an assembly of wood–geopolymer–earth bricks

Gouny, F. / Fouchal, F. / Pop, O. / Maillard, P. / Rossignol, S.

Graphical abstract Display Omitted Highlights ► Geopolymer binder gives good adhesion between wood and earth. ► Shear results are similar to thus obtained on fired brick with cement mortar masonry. ► The Brick nature has an important effect on the mechanical behavior of masonry samples. ► The binder penetrates inside the earth creating a new phase.

Abstract Timber frame construction with earth brick infill is a sustainable design that is promising in the building construction field. However, cracks form at the interfaces of the bricks and frame with temperature and humidity fluctuations. A geopolymer binder can create stronger bonds between these two materials than traditional mortar, potentially preventing crack formation. This study focuses on the pull-out and shear mechanical behavior of laboratory assemblies of wood, geomaterial binder and two different types of earth brick. The full-field displacements of double-shear test samples were also obtained by digital image correlation (DIC) to better describe and understand the mechanical behavior of the system. The results show that the geopolymer binder provides good adhesion of approximately 1.5MPa or 2MPa, depending on the type of brick. Failure localization is also different for each assembly, occurring inside the brick and binder or only inside the binder. This result is confirmed by DIC analysis. The microstructure of the brick has been correlated with the mechanical behavior of the assembly. First results show that the geopolymer binder can be used as a joint in wood and earth masonry.