Physicochemical and mineralogical characterization of earth for building in North West Italy

A mineralogical and morphological investigation was conducted on unstabilised sun-dried adobes (UBs) taken from rural constructions in Asti (North West Italy) that date the nineteenth century. Since not all soils can be used for housing material, an evaluation and a characterization of their constituents play important roles in developing efficient and durable adobe building materials. A particle size distribution, XRD, TG–DTA, SEM–EDAX analysis and porosimetry were carried out to characterize the constituent materials of UBs and to compare them with several other soils collected in the Asti and Alba areas. More than fifty different soils have been sampled from neighbouring outcrops and quarries around the rural constructions. The most significant samples, with a granularity close to the UBs grain size distribution, were selected and their mineralogical composition compared with the adobe composition. The comparison allowed the original sites of the UB raw earth to be identified.