This research delves into the realm of asphalt technology, exploring the potential of nano-additives to enhance traditional asphalt binder properties. Focusing on Nano-Titanium Dioxide (NT), Nano-Aluminum Oxide (NA), and Nano-Silica Oxide (NS), this study investigates the effects of incorporating these nanomaterials at varying dosages, ranging from 0% to 8%, on the asphalt binder’s performance. This study employs a series of experimental tests, including consistency, storage stability, rotational viscosity, mass loss due to aging, and rheological properties, to assess the impact of nano-additives on asphalt binder characteristics. The findings indicate a substantial improvement in the consistency of the asphalt binder with the addition of nanomaterials, particularly NS, which shows a 41% reduction in penetration at an 8% content and a notable increase in the softening point. The storage stability tests reveal that NS-modified asphalt exhibits superior stability compared to NT and NA, with a significantly lower ΔT increase. Furthermore, the investigation into rotational viscosity suggests that NS, despite increasing the binder’s viscosity, does not exceed the AASHTO M320 threshold, ensuring the binder’s workability. Aging tests demonstrate that NT, at lower concentrations, acts as an effective anti-aging agent, whereas NA and NS tend to increase the mass loss, impacting thermal stability. This study concludes that while each nanomaterial uniquely influences the asphalt binder’s properties, NS stands out in terms of enhancing the high-temperature performance and storage stability. Optimal dosages of 6% for NT and NA and 4% for NS are recommended based on the Overall Desirability analysis. This research bridges the gap between traditional asphalt materials and modern requirements, highlighting the transformative impact of nano-additives in advancing asphalt pavement technology.

Asphalt mixtures exhibit deterioration in properties due to several factors; one of these factors is the moisture damage. Many kinds of research have focused on this matter in Iraq; however, up to now, the pavement is suffering from moisture failure due to the penetration of surface water. Asphalt concrete is modified in this research by adding anti-stripping agent and polymer to withstand the moisture damage that occurs in the pavements. Key factors to enhance the mixtures to withstand the damages due to moisture are aggregate–binder cohesion and adhesion. Therefore, the aim of this research is to evaluate the effect of the addition of the anti-stripping agent and the polymer on the moisture susceptibility of asphalt concrete mixtures before and after conditioning. Indirect tensile strength test, Marshall test, and double punching shear test are used to satisfy the evaluation of the mixture properties. The anti-stripping agents that are used were WetFix with styrene butadiene styrene (SBS) polymer with different percentages. It is found that the modified asphalt mixture has good mixture properties in terms of Marshall stability, retained Marshall stability, and better resistance of moisture and stripping. It has been found that the addition of 0.5% WetFix and 3% SBS polymer maximizes the properties among other percentages. It is also observed that the mixing technique of modifiers is important to the resulting performance of asphalt mixtures.

Sustainable pavements are pavements that meet the requirements of present generation without influencing the capability of the future generation to meet their needs. One of the problems of the warm mix asphalt is that it has low resistance to moisture damage; therefore, the aim of this research paper is to study the possibility of producing more durable warm mixes against the moisture damage with the use of recycled concrete aggregate (RCA) which has not been studied before. Six replacement rates (0, 20, 40, 60, 80, and 100%) for the coarse version aggregate (VA) with RCA were studied. The Marshall mix design method was used to determine the optimum asphalt cement content for each replacement rate. Thereafter, specimens with the optimum asphalt cement content were prepared and tested in the indirect tension test to evaluate their moisture susceptibility. The results revealed that the mixes with higher percentage of RCA possess higher optimum asphalt content. Moreover, an improvement of 13 and 28% in Marshall stability and tensile strength ratio (TSR), respectively, was obtained in case that the VA was entirely replaced by the RCA.

Recently, interest in the use of projectiles in research on recycling waste materials for construction applications has grown. Using recycled materials for the construction of asphalt concrete pavement, in the meantime, has become a topic of research due to its significant benefits, such as cost savings and reduced environmental impacts. This study reports on comprehensive experimental research conducted using a typical mechanical milling waste, iron filing waste (IFW), as an alternative fine aggregate for warm mix asphalt (WMA) for pavement wearing surface applications. A type of IFW from a local machine workshop was used to replace the conventional fine aggregate, fine natural sand (FNS), at percentages of 25%, 50% 75%, and 100% by the weight of FNS of the size passing sieve No. 50. Experimental tests were conducted on the mixes to compare their Marshall properties, resilient moduli, rutting and fatigue resistance, and moisture susceptibility. Finally, a performance analysis was carried out using the VESYS 5W software on the constructed pavement using the IFW mixes. Both the experiment and the modeling work demonstrated that IFW can be an effective alternative resource for replacing natural fine aggregate in WMA concrete and provided details on the optimum rate based on the comprehensive data obtained first hand.

Rapid worldwide urbanization and drastic population growth have increased the demand for new road construction, which will cause a substantial amount of natural resources such as aggregates to be consumed. The use of recycled concrete aggregate could be one of the possible ways to offset the aggregate shortage problem and reduce environmental pollution. This paper reports an experimental study of unbound granular material using recycled concrete aggregate for pavement subbase construction. Five percentages of recycled concrete aggregate obtained from two different sources with an originally designed compressive strength of 20–30 MPa as well as 31–40 MPa at three particle size levels, i.e., coarse, fine, and extra fine, were tested for their properties, i.e., the optimum moisture content density, Californian bearing ratio, and resilient modulus. A characterization of the resilient modulus of the mixes under complex stress conditions was performed. The characterized modulus model was used in the nonlinear analysis of the pavement structure under traffic loading using KENALYER software. Consequently, the two critical responses, i.e., the tensile strain at the bottom of the asphalt layer and the vertical compressive strain at the top of the subgrade, were computed and compared for the pavement structures with varying types and percentages of recycled concrete aggregate used in the subbase layer.