A procedure to assess suitability of plaster to protect vernacular earthen architecture

As part of a working definition of a new code of practice, a methodology is being defined to determine the suitability of plasters manufactured on-site to protect earthen wall of vernacular architecture buildings. Given the diversity of raw earth construction methods, ranging from massive earth to stone masonry with earth mortars, and the variability of the materials used, it was proposed two on-site testing: a shrinkage test followed by a shear test. These tests, as well as additional tests, were performed on an earthen wall using two different earth plasters. This first testing campaign has permitted to validate the on-site shrinkage test but not the on-site shear test. A future testing campaign will explore the influence of various parameters on the shear test.