This study investigated the incorporation of soybean oil, first in the ranking of Brazil production, in a partial substitution to two types of asphalt binder (pure and with Styrene–Butadiene–Styrene – SBS) in order to produce warm-mix asphalt (WMA). The oil was incorporated into two conditions: new and waste, and the mix was obtained with 1%, 2% and 3% of soybean oil. The samples were analysed using the tests of penetration index, softening point, rotational viscosity, performance grade (PG), and multiple stress creep and recovery (MSCR). The results show that the addition of 1% content of new and waste soybean oil improved physical and rheological characteristics of asphalt binders. The decrease in mixing and compaction temperature was obtained in 2.7°C average for 1% of waste oil with pure asphalt binder and 3.4°C average for a 1% of new oil with asphalt binder with SBS, considering only the criterion of the viscosity curve.

The global engineering plastics market has been growing as it replaces materials such as glass and metal. It can be used in a wide variety of products and technologies in other sectors of the economy such as energy generation, automotive, maritime, construction, electronics, packaging, and others. However, this increase in global use presented problems with respect to the increase in plastic waste generation. The existence and destination of plastic waste in the soil and hydric resources has been recognised as an emerging issue in preserving the environment. In this research, Micronized Polyethylene Terephthalate (micronized PET) was used as an additive for asphalt mixtures. The polymer was mixed in amounts of 4%, 5%, and 6% by weight with an asphalt binder base and mechanical tests were performed. Two SUPERPAVE mix design methods were performed. The first one was made with pure binder and the optimum binder content was determined and the specimens were analysed according to the following parameters: Resilient Modulus (RM), Lottman, and Indirect Tensile Strength (ITS). A second mix design procedure was performed with the optimum PET content according to the best results obtained in the first one, and analysed according RM, ITS, Lottman, Fatigue, and Flow Number tests. The results show significant improvements on mechanical properties of the asphalt mixtures with micronized PET compared with asphalt mixtures without additive.

The increase in living standards and social and economic development over the past three decades has increased the demand of waste discarded in the environment. In the last five years due to the widespread application of polyethylene terephthalate (PET) waste, improper disposal has become a serious problem in the maintenance of an environmental balance. Some additives have been developed during the last decades in order to improve the mechanical properties of asphalt binder according the rheological properties. This research aims to evaluate the implementation of PET in a modified binder. PET was mixed with the percentage of 4, 5, and 6 wt% within a binder. It was found that progressive addition PET increased pulp consistency and improved its elastic response. Addition of PET showed promise in antiaging action, as the higher oxidation levels decrease modified binders.

Stone Matrix Asphalt (SMA) is a gap-graded mixture which requires high contents of asphalt binder. To prevent draindown, natural or synthetic fibres and polymer-modified asphalt binders are conventionally used in SMA. Banana agribusiness is one of the major sources of post-harvest residue in Brazil. Amongst those residues, fibres extracted from the pseudostem of the banana plant are resistant and used in diverse purposes. The present study assesses the incorporation of fibres from the pseudostem of the banana plant in an SMA mixture. The fibre contents and lengths capable to prevent binder draindown were evaluated from draindown tests. Mechanical properties of an SMA mixture stabilised with different banana fibre lengths were analysed through the tests of Marshall stability, modified Lottman, Indirect Tensile Strength and Cantabro. The results indicated that the fibres studied are a viable alternative for SMA, stabilising draindown and improving its mechanical performance, especially at the length of 20 mm.