Mechanical analysis of fiber reinforced adobe

Abstract

The south-east of the kingdom of Morocco, including the Tinejdad region at the south-east, has a remarkable earthen architecture. It is built by combining two techniques, that of rammed earth and that of adobe. This work is carried out with the aim of preserving and developing this ancestral know-how. The study is initially a characterization of the soil used for earthen construction in the region; the grain size and plasticity of the soil showed that it was not very clayey and moderately plastic (clayey sand) and it was suitable for earthen construction. The characterization also concerned the fibers traditionally used, namely wheat straw and barley straw. Secondly, the study focuses on the influence of different fibers, those mentioned above as well as sawdust and the crushing of barley straw on the mechanical characteristics of adobe in relation to its compressive strength and bending strength. Several fiber mass ratios were studied, and an improvement in compressive strength and bending strength was observed for the different fibers. The fibers have also provided a great improvement in the ductility of the adobe and a decrease in the modulus of elasticity. The optimal mass ratio of the fibers was 2% for the different fibers studied.