Influence of vegetable fibers on drying process and stability in water of clay-sawdust wood brick

The composite subjected to our study is obtained by mixing the clay and the sawdust. The sawdust has an important intrinsic porosity, because of presence of capillaries. Clay is a fine mineral, used as binder. The mixture of these components of nature with very different characteristics, led to a material which properties will be variable according to the voluminal concentrations of each component. Clay is used in the form of fine, with a granulometric size overall lower than 1 mm. It is a clay of the type kaolinic, plastic, containing illite and quartz. The sawdust, being used as reinforcement material, is used in its natural form (without treatment). It is presented mainly in granular and powdery forms, but it also contains short fibers. The results of the study show the water absorption coefficient of bricks drops when one of them incorporates 5 to 15% sawdust; it increases beyond 15%. These results also show that the bricks containing the clay and the sawdust have evaporation rates and withdrawal lower than those of bricks without sawdust. Moreover, after 4 days of total immersion of bricks, the results show that the composites clay-sawdust of wood is more resistant to water compared to the bricks without sawdust which dissolve completely. All these results make it possible to conclude that the sawdust influences indeed absorption rate, drying process and the conduct in the water of compressed ground bricks reinforced with the sawdust.