Análise do uso das fibras do pseudocaule da bananeira em misturas asfálticas SMA.

Abstract

Stone Matrix Asphalt (SMA) is an asphalt mixture that optimizes stone-to-stone contact due to its large coarse aggregate fraction, increasing the shear strength of the pavement surface layer and consequently its structural performance. Synthetic fibers and polymer modified asphalt binders are generally used to prevent draindown due to high contents of binder employed in this type of mixture. The agribusiness of banana, which has a great importance in the Brazilian and Northeastern economies, is one of the major generators of post-harvest rejects, highlighting the false stem of the plant from which can be extracted fibers considered of good quality for application in diverse purposes. The aim of the present research was to analyze the feasibility of incorporating Pacovan banana false stem fiber (cultivar most produced in the country, mainly in the Northeast region) in SMA mixtures and evaluate the influence of these fibers length on the performance of the mixture. For this purpose, draindown tests were performed to identify the ideal banana fiber content in order to decrease binder draindown and evaluate the influence of fiber length on this parameter. Afterwards, tests were performed to determine the mechanical properties of the binder (stability Marshall, modified Lottman, tensile strength, Cantabro, resilience modulus, controlled stress fatigue, dynamic modulus and flow number) using the optimal fiber content obtained and varying the length of the fiber. In general, the results indicated that the fiber from the false stem of Pacovan banana plant may be a viable alternative for SMA, both for the stabilizing capacity of draindown and for improvements in the mechanical properties of the mixture. The length of 20mm provided the best performance of SMA.