Asphalt Pavement Research Articles (Page 1)

The reuse of reclaimed asphalt pavement (RAP), sourced from the milling of existing pavements, offers an eco-friendly alternative to natural aggregates. It offers significant environmental benefits by reducing landfill waste and limiting the exploitation of natural resources. This study investigates the potential incorporation of fine RAP (FRAP) in the production of sand concrete, a particular type of concrete composed solely of fine aggregates. Firstly, five sand concrete mixtures were designed by partially or fully replacing natural sand with FRAP and were then assessed in terms of their mechanical characteristics and durability-related indicators. The results revealed that FRAP can be successfully used to produce sustainable sand concrete at replacement levels up to 50%, meeting all the mechanical performance requirements for pavement applications. The incorporation of FRAP also resulted in increased water absorption by immersion and higher sorptivity values. Yet, these values remained within the permissible limits for mixtures with 50% or less FRAP. Furthermore, given the critical role of elastic modulus in rigid pavement design, three predictive models were evaluated to estimate the elastic modulus of FRAP mixtures. The findings indicated that, when incorporating a correction factor reflecting aggregate quality, the ACI 318 model provided the highest accuracy, achieving a root mean square error of 1.5 GPa. The study confirmed the feasibility of reusing RAP in sand concrete, offering practical guidance for engineers to adopt this technique in pavement applications and encouraging greener construction practices.

The asphalt industry is increasingly urged to adopt sustainable practices by utilizing bio-based and recycled resources. This study evaluates the performance of warm mix asphalt (WMA) modified with chitosan derived from shrimp shell waste (SSPCH). Chemical characterization of modified bitumen was conducted using SEM and FTIR, while mechanical performance was assessed through Marshall stability, repeated load axial, indirect tensile strength (ITS), and semi-circular bending tests. Results identified an optimal SSPCH content of 6%. This modification significantly enhanced rutting resistance, reducing permanent strain by 38% compared to the control. The modified mixtures also met ASTM D4867 requirements, showing a 24.5% increase in ITS and a 23% improvement in Tensile Strength Ratio (TSR), indicating superior moisture damage resistance. The enhancement is attributed to SSPCH's physicochemical properties, which promote a stronger bitumen-aggregate bond. This research confirms SSPCH as a viable bio-additive for developing more durable and sustainable asphalt pavements.

Abstract This study investigated the environmental and performance benefits of using reclaimed asphalt pavement (RAP) in street construction, emphasizing its role in reducing greenhouse gas emissions and promoting sustainable practices. The performance of newly constructed asphalt layers by incorporating technological control, the functional parameters, and a life cycle assessment (LCA) of asphalt mixture production are evaluate. By combining natural aggregates, asphalt binder, and RAP, produced at lower temperatures than conventional mixes, the study demonstrated a 24.9% reduction in greenhouse gas emissions, along with decreased natural material consumption. Technological control focused on the degree of compaction (DC), whereas functional performance was assessed using the International Roughness Index (IRI) and macrotexture tests. Among the 26 streets analyzed, 69% met the National Department of Transportation Infrastructure (DNIT) standards, with IRI results ranging from regular to excellent. According to ASTM E1926-08, 65% of streets were suitable for speeds of 100–120 km h −1 , whereas only 4% supported speeds below 90 km h −1 . Macrotexture tests revealed that 62.5% of the pavements had a medium texture, ensuring safe traffic conditions. LCA highlighted the significant reduction in Global Warming Potential (GWP) achieved through RAP, as well as its economic advantages, such as lower energy demand and reduced reliance on virgin materials. These findings underscore RAP’s dual benefit: enhancing pavement sustainability while maintaining high-performance standards, making it a viable solution for eco-conscious infrastructure projects.

Hot recycling of reclaimed asphalt pavement (RAP) in new hot mix asphalt (HMA) including polymer-modified bitumen (PmB) is problematic because the SBS in the RAP would be degraded or absent. To avoid this issue, the use of highly modified asphalt (HiMA) with an increased SBS content has been recently proposed. In the present study the rheological and performance behaviour of a blend including 50% of HiMA and 50% of RAP bitumen was evaluated in comparison with a reference virgin PmB and a blend including 50% of PmB and 50% of RAP bitumen treated with an ordinary recycling agent. The blend of HiMA and RAP bitumen showed an excellent performance in terms of resistance to permanent deformation and fatigue behaviour, as the excess of SBS in the HiMA entailed a noticeably marked elasticity of the bituminous blend. However, ageing caused a significant decrease of the performance for the HiMA + RAP blend.

The long-term service of semi-rigid base asphalt pavements often leads to the formation of interlayer voids, a distress mode that is more severe than conventional debonding. This study employed a continuous-discrete coupled model to systematically investigate the influence of void width, void height, and material modulus on pavement mechanical behavior. The results indicate that increasing the void width markedly elevates interlayer shear stress and induces a transverse tensile stress zone at the bottom of the overlying layer, promoting simultaneous crack propagation in both transverse and upward directions. Conversely, as void height increases, the interlayer shear stress and the tensile stress zone diminish, allowing the pavement structure to settle into a new, relatively stable equilibrium state. Additionally, increasing the modulus of the lower surface layer effectively reduces both transverse tensile and shear stresses, thereby mitigating further void deterioration. These findings elucidate the complex mechanical responses induced by interlayer voids and offer theoretical guidance for improving structural design and prolonging the service life of asphalt pavements.

Cold recycling is a proven alternative to traditional remove-and-replace maintenance and rehabilitation strategies. However, implementation by road agencies across the United States has been limited, which can be attributed to a number of reasons. One primary reason is believed to be that cold recycling strategies do not readily fit current agency flexible pavement management frameworks, which have been established around remove-and-replace maintenance and rehabilitation strategies, or fit the traditional definitions for routine, preventative and corrective maintenance, and minor and major rehabilitation. These frameworks, and the decision processes associated with them, need to be updated to better accommodate new strategies, in conjunction with traditional strategies, to make the best use of available resources to cost-effectively and more sustainably extend the life of pavement networks and improve the overall condition of the network. This paper summarizes developments in cold recycling, identifies barriers to implementing cold recycling in agencies, and suggests a roadmap framework for updating policies and procedures to make better use of cold recycling. When designed and built appropriately, cold recycling strategies can be more cost-effective and more sustainable than traditional remove-and-replace strategies. Optimizing the recycling depth to remove distresses and provide the required structural support for the asphalt concrete surfacing for a given set of traffic, climate, environmental, and resilience criteria is critical for a successful outcome. Attempting to align recycle depths within maintenance and rehabilitation categories that are specific to traditional remove-and-replace strategies will yield less-than-optimal results and the potential for significant benefits will not be realized.

Investigating rupture behavior and healing efficacy of self-healing microcapsules in asphalt pavements through multiscale simulations

Environmental and Economic Assessment of Roller Compacted Geopolymer Concrete with Reclaimed Asphalt Pavement

Development of Structural Condition Models for Asphalt Pavements Based on Surface Distresses: an Iranian Case Study

De-icing property of composite superhydrophobic coatings with various microwave absorbing materials on asphalt pavement

Characterization on thermal fatigue damage in asphalt pavement under cyclic temperature variations

Thermal modeling and optimization of a self-heating tack coat for asphalt pavement under radiative heating

The integration of nanomaterials in asphalt modification has emerged as a promising approach to enhance the performance of asphalt pavements, particularly under high-temperature conditions. Nanomaterials, due to their unique properties such as high surface area, exceptional mechanical strength, and thermal stability, offer significant improvements in the rheological properties, durability, and resistance to deformation of asphalt binders. This research reviewed the application of various nanomaterials, including nano silica, nano alumina, nano titanium, nano zinc, and carbon nanotubes in asphalt modification. The incorporation of these nanomaterials into asphalt mixtures has shown potential to increase the stiffness and high-temperature performance, thereby reducing rutting potential and improving the overall lifespan of the pavement. The mechanisms by which nanomaterials enhance the thermal and mechanical properties of asphalt were explored. Furthermore, the challenges associated with their implementation were examined, as effective utilization is hindered by agglomeration, inconsistent dispersion, and dosage sensitivity, compounded by the absence of standardized guidelines and the variability in reported contents. The findings indicate that while nanomaterials hold considerable potential for improving high-temperature asphalt performance, further research is needed to optimize their use and fully realize their benefits in large-scale applications.

Boosting semi-flexible asphalt pavement sustainability and performance with rice husk biochar particle

A review of the near-infrared reflective coatings for cooling asphalt pavements in permafrost regions

A new method for predicting carbon emissions of paver during construction of asphalt pavement layer based on deep learning and MOVES-NONROAD model

Structural control and performance evaluation of polyurethane-based solid–solid phase change materials for thermal regulation of asphalt pavements in high-temperature climate conditions

Characterization and mitigation of air-coupled GPR antenna vibration during traffic-speed estimation of asphalt pavement dielectric constant

Effects of clogging on void characteristics and sound absorption properties of porous asphalt pavements

The evolution of three-dimensional characteristics of asphalt pavement texture top topography with contact depth