Jute fabric as a reinforcement for rammed earth structures

This paper reports the results of an experimental campaign that aims at evaluating the capability of a composite made of jute fabric and stabilized earth matrix to act as a reinforcement of earth structures, and the analytical models able to interpret the results. Preliminary studies carried out in order to test adequate reinforcement systems for earthen structures, demonstrated that jute fabric applied with a stabilized earth plaster, among other natural fibers or systems, is able to develop exceptional adhesion and adequate stiffness. However, the collapse mechanisms observed seems to favor the rupture of reinforcement rather than the crisis of adhesion usually observed when dealing with artificial FRC reinforcements. It was necessary to step back to the theories of adhesion to plan the experimental analysis of the jute reinforcement for rammed earth structures. The poor material, the fact that adhesive and support are almost the same material (differing only for grain size, density and a small amount of gypsum), the difficulty in measuring fabric properties, strength and, most of all, local deformation and fracture energy in earthen materials, induced to define a specific procedure. The uncertainties connected to the determination of mechanical parameters were overcome both using statistical approach and numerical analysis of data, and reducing the number of parameters necessary to the analysis, that is turning to simple adhesion models.