Emprego de agregados minerais de Mato Grosso em pavimentos flexíveis de concreto asfáltico

Abstract

The importance of studying the use of aggregates in paving supported by advances in improving techniques and processes in the design and execution of road construction, conservation and maintenance works. In addition, it aims to increase the technical framework. This work initially characterizes the stone materials of limestone and sandstone origin and determines the granulometric compositions and the traces of the asphalt mixtures in order to evaluate the mechanical behavior of the mixtures with CAP 60/85 polymer binder through the tensile strength tests and resilience. Regarding the characterization of the aggregates, an expressive result related to absorption, where the limestone presents only 0.3% and the sandstone 1.0%. After characterizing the aggregates, the binder content of the design mixture is 5.10% for limestone and 6.35% for sandstone, representing the impact of absorption on the consumption of binder. The resulting 3.35% void volume of the limestone and 4.56% in the sandstone; bitumen / voids ratio 79.05% (limestone) and 77.42% (sandstone) are reflections of the absorption characteristic that expresses the difference between the two groups of aggregates. The stability of the mixtures is above the minimum of 500 kgf, 2057.2 kgf (limestone) and 2138.0 kgf (sandstone) which reflect in a comparative way the proximity of the shape index between the two stone groups, being the crushed stone 1 of sandstone closer to cubicity (0.84) than limestone (0.78). The small difference in result also found in creep, where the displacement is 3.35 mm for limestone and 3.53 mm for sandstone. The tensile strength of the mixtures is not in accordance with the DNER-ES 385/99 standard, where sandstone and limestone reached 23.6 kgf / cm² and 19.4 kgf / cm², respectively, outside the range of 7.0 - 12.0 kgf / cm². Although the resilience modulus is very high in both groups, their RT values help in the MR / RT ratio of limestone and sandstone, 3377.5 MPa and 2701.7 MPa respectively, which are close to mixtures from other studies. This shows that the two groups (sandstone and limestone) have a good fatigue life, with emphasis on the sandstone that has the best indicator. Even with the results of this study, complementary work still needed to defer the application of mixtures with polymers with sedimentary aggregates.