Three-Leaf Stone Masonry Strengthened by Injecting Cement Grouts

Abstract
In a large number of monuments and buildings belonging to urban nuclei, the walls are made of the so-called three-leaf stone masonry (i.e., two stone masonry “face” walls with a gap between them filled with low quality mortar and small pieces of stone). In this paper, the effect of injecting cement-based grouts in such walls is experimentally investigated on wallets subjected either to vertical or to diagonal compression. A drastic improvement of mechanical characteristics is observed thanks to the homogenization of the three-leaf masonry after the injection of the grout.