Evaluation of air lime and clayish earth mortars for earthen wall renders

An experimental rammed earth wall was made and characterized in exterior environmental conditions. Two mortars were prepared with an air lime and a mixture of sands, with volumetric proportions of 1:2 and 1:3 (air lime:sand). A clayish earth was applied on mortars as partial substitutions of the air lime or of the finest sand. Mortars were characterized and samples of mortars and applied on ceramic brick were prepared. For each volumetric proportion, mortars without earth and the ones with earth that presented the best workability were applied as renders on panels on the wall. The mortar samples and the renders on the wall were characterized at 90 days of age. Results obtained with the characterization of the rammed earth wall, the fresh mortars and its application on the bricks and on the wall are discussed. Differences between the mortars are highlighted while their compatibility with traditional rammed earth wall is verified.