Mechanical behavior of structural elements in rammed earth reinforced with jute fabric

Starting from the awareness that the mechanical characteristics of raw earth are sufficient for structural use, two arches and one wall 1:3 scale models in rammed earth were made. The two arches, one with only earth and one with earth mixed with gypsum powder and the wall were subjected to mechanical tests. Preliminarily tests were performed in order to asses mineralogical geotechnical and mechanical earth's characteristics. The three earthen structural elements were subjected to monotonically increasing load up to incipient collapse. Subsequently the same damaged elements were strengthened with jute fabric and tested again in order to verify the reinforcing ability of the fabric. The strengthened arches and the reinforced wall showed a load-bearing capacity respectively 3 times and 1,5 times higher than that of unreinforced structures. In order to set up a numerical method for the prediction of the mechanical response of such structures a FEM analysis was performed using the code ADINA. The prediction provided by the numerical results are in good agreement with the experimental ones. The biocompatible reinforcement made with vegetable fiber and earthen matrix showed that it is possible to significantly increase both bearing capacity and ductility of these structural elements and can therefore also be used for seismic retrofitting. Due to lack of available space, in what follows only the results of mechanical and numerical tests on the wall are reported.