Grouts for strengthening two- and three-leaf stone masonry, made with earthen mortars

Earth was used in the past to produce mortars either on its own or in combination with other materials (such as lime and sand). Earth mortars were used both in adobe and in stone masonry structures. This article aims to study stone masonries made with earth mortar and their strengthening by grouting. Six wallettes were constructed, in order to study the mechanical properties of the two- and three-leaf stone masonry before and after grouting. In parallel, several compositions of grouts, having different ratios of hydraulic lime (NHL5), earth and water, were designed and evaluated regarding their injectability properties (fluidity-penetrability, stability tests). Moreover, flexural and compressive strength tests were performed. Thus, this project led to the development of a number of suitable mixes that satisfy the performance criteria set for their design. The suitability of those mixes from the mechanical point of view was checked by injecting them to wallettes, subsequently tested in compression.