The SMA mixtures are characterized by a high void ratio, which favors binder draindown. In order to avoid this effect, fibers are added to the mixture, which in this case came from Curauá da Amazônia (Ananas erectifolius). The final composition studied resulted in 75% coarse aggregate, 15% fine aggregate, 10% filler, 0.3% of the Curauá fiber residue, and CAP contents equal to 6.50% and 6.88% for the formulations with SMA-Crushed Stone (reference) and SMA-construction and demolition waste (alternative), respectively. The results showed for the Tensile Strength that the composites with CDW reached higher results. The Resilient Modulus values presented small variations for the set of compositions in all loading levels at a temperature of 25°C. However, at a temperature of 40°C, the aforementioned parameter presented decreases in both researched formulations. In general, at all levels examined, higher results were observed for the alternative mixture (SMA-CDW). It is noteworthy the highest results of this parameter when comparing the compositions with the Curauá fiber residue and the formulations mentioned in the literature, with the presence of other types of fibers. Regarding the increase in temperature, there was a decrease in results for both mechanical parameters (TS, DM), but with lower losses for the SMA-RCD composition.

Este trabalho avalia o comportamento mecânico do concreto asfáltico embebido em grafite natural (CA-GRAFP) de um aparelho de flexão de 4 pontos. Os modelos experimentais apresentaram frequências de 0,1 Hz, 0,2 Hz, 0,5 Hz, 1 Hz, 2 Hz, 5 Hz, 10 Hz e 20 Hz e temperaturas de 0 ° C a 40 ° C em incrementos de 5 ° C conforme EN 12697 -26. O objetivo foi avaliar o uso de grafite natural na substituição de uma carga tradicional, bem como avaliar as propriedades relacionadas à rigidez resultante de inúmeras combinações de carga. Os resultados mostraram que as amostras de concreto asfáltico embebido em grafite (CA-GRAFP) tiveram um aumento no seu módulo elástico quando comparado ao concreto asfáltico de referência (CA-REF) à medida que a frequência e a temperatura aumentaram.

Relevant mechanical parameters of asphalt composites, such as the dynamic modulus and phase angle, are obtained by means of four-point bending tests. It is a dynamic test based on the application of sinusoidal load pulses and sinusoidal displacement response. A sinusoidal response can be difficult to record due to different issues, such as noise during an experiment. In strain-controlled tests with the application of a low-load amplitude with asphalt mixtures at high temperatures composed with calcined clay, which is the case of the test carried out in this study, a relationship was observed between the apparent noise recorded and the frequencies of the beam's natural vibration. This outcome led to the conclusion that these imperfections are not a result of failures in the procedure, but of the natural behavior of the beam. This conclusion can assist in the filtering of information to obtain better results.

Soil stabilization for use in pavement sublayers has been established in Geotechnical En-gineering as an option for pavement construction. In this context, certain alternative materials stand out, such as coal and biochar, which are able to fulfill this function when added to the soil, being the object of study in the present research. These products originated from char-coal furnaces and biomass carbonization under low oxygen atmosphere. In the present study we evaluated the natural soil and compositions according to the four-point bending test, for simulating vehicle tire-loads on the pavement. For this purpose, we molded prismatic speci-mens with natural soil (NS) typical of the Amazon region, with natural soil-10% charcoal (SCH) and soil-10% biochar (SBC). It was verified that the soil-biochar mixture (SBC) pre-sented better results, culminating in higher values of complex modulus when compared to the natural soil (NS) and soil-charcoal mixtures (SCH). Regarding the phase angle parameter and the analyzed set (NS, SCH e SBC), values close to zero were observed. Therefore, this article presents the possibility of using alternative materials for executing road systems with better performance.