Efeito da adição de fibras de coco em misturas cimentadas com agregados reciclados para subcamadas de pavimentos

Abstract

The increasing traffic on roads has required more resistant pavement underlays from a mechanical point of view. The use of cement mixtures is an alternative to meet this need, however, these materials may have defectssuch as reflection cracks. The use of fibers can be beneficial in reducing these cracks. Thus, the general objective of this research was to analyze the change in mechanical behavior, with the addition of coconut fibers, of cemented mixtures for use in pavement sublayers. The analyzed mixtures, in addition to containing soil and cement, were composed of recycled aggregates from construction and demolition wastewaste, to contribute with more sustainable solutions in the paving area. Mechanical tests were performed, such as Modulus of Resilience (MR), Resistance to Simple Compression (RCS) and Tensile Strength by Diametral Compression (RTCD). As a result, the cemented composites, with and without fibers, were analyzed and proved to be suitable for use in paving, considering the current specifications. The mixtures containing fibers and content of 7% of cement, by mass, presented a better mechanical behavior, considering the results of the MR tests. In general, the insertion of coconut fibers changed the mechanical behavior of the mixtures, giving ductility, which consequently should result in less reflection of cracks for the coating, in case they are used in pavement base layers. However, some aspects, such as the behavior of materials to fatigue and the investigation of possible environmental impacts, still need to be studied to verify the financial and environmental viability of the use of these materials.