Journal of Road Engineering最新文献

Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements, bridges, tunnels, and accessory structures. The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads. This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes: industrial solid waste, infrastructure solid waste, and municipal life solid waste. Industrial solid wastes suitable for road engineering generally include coal gangue, fly ash, blast furnace slag, silica fume, and steel slag, etc. Infrastructure solid wastes recycled in road engineering primarily consist of construction & demolition waste, reclaimed asphalt pavements, and recycled cement concrete. Furthermore, recent exploration has extended to the utilization of municipal life solid wastes, such as incinerated bottom ash, glass waste, electronics waste, plastic waste, and rubber waste in road engineering applications. These recycled solid wastes are categorized into solid waste aggregates, solid waste cements, and solid waste fillers, each playing distinct roles in road infrastructure. Roles of solid waste acting aggregates, cements, and fillers in road infrastructures were fully investigated, including their pozzolanic properties, integration effects to virgin materials, modification or enhancement solutions, engineering performances. Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development. However, challenges such as variability in material properties, environmental impact mitigation, secondary pollution to environment by leaching, and concerns regarding long-term performance need to be further addressed. Despite these challenges, the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship. This review delves into a bird’s-eye view of the utilization of recycled solid wastes in road engineering, highlighting advances, benefits, challenges, and future prospects.

Rigid-flexible composite pavement has gained significant popularity in recent decades. This paper provides a comprehensive review of the research progress concerning rigid-flexible composite pavement, aiming to promote its application and address key issues while identifying future directions. The design theory and methodology of rigid-flexible composite pavement are discussed, followed by a description of its structural and mechanical behavior characteristics. The load stress, temperature stress, and their interactive effects between the asphalt layer and the rigid base were analyzed. It is clarified that the asphalt layer serves a dual role as both a “functional layer” and a “structural layer”. Typical distresses of rigid-flexible composite pavement, which primarily occur in the asphalt layer, were discussed. These distresses include reflective cracking, top-down cracking, rutting, and compressive-shear failure. Generally, the integrity of the rigid base and the interlaminar bonding conditions significantly impact the performance and distress of the asphalt layer. The technology for enhancing the performance of rigid-flexible composite pavement is summarized in three aspects: asphalt layer properties, rigid base integrity, and interlaminar bonding condition. The study concludes that developing high-performance pavement materials based on their structural behaviors is an effective approach to improve the performance and durability of rigid-flexible composite pavement. The integrated design of structure and materials represents the future direction of road design.

Many industrial sectors exploit fossil sources to develop useful and necessary materials for our needs, such as bituminous paving materials. Bitumen, a key component of asphalt mixtures, is derived from oil refining and its properties are influenced by the crude oil source and refining process, resulting in a significant carbon footprint. With growing awareness of resource depletion and environmental concerns, pavement researchers are exploring sustainable alternatives to reduce dependence on fossil sources. This includes a rising trend in using renewable materials like biomasses to produce bio-based binders as substitutes for bitumen, aiming for a more sustainable approach. Biomasses, including vegetal and animal wastes, and waste cooking oils, as substitutes for crude oil in the production of bio-binders. Through thermochemical conversion (TCC), such as pyrolysis, biomasses can be converted into bio-char and bio-oils, which can replace fossil-based components in binders. Researchers have utilized these bio-products to reduce the dependency on fossil fuels in binders. However, there are no set minimum requirements for bio-components in bio-based binders. As the percentage of replaced bitumen increases, various types of binders are produced, including modified bitumen, extended bitumen, and alternative binders, where the fossil replacement is gradual. Overall rheological tests on bio-binders, reveal that those containing bio-char exhibit increased viscosity, stiffness, rutting resistance, and sometimes antioxidant properties. Conversely, bio-binders with bio-oils as bitumen substitutes show poorer performance at high temperatures but improved behavior at low temperatures. These results suggest that bio-binders could provide versatile solutions for various climatic and loading conditions in road construction. However, the development of pavement mixtures based on bio-binders has not been studied in depth and requires further attention to unlock its full potential. As sustainability considerations, including life cycle assessments (LCA) and life cycle cost analyses (LCC), are crucial aspects for future studies. It is essential not only to collect data on the performance characteristics of bio-binders but also to understand their environmental impact and recyclability. In-depth evaluations using methods such as LCA and LCC will provide valuable insights into the overall sustainability and long-term viability of these products.

Road transportation plays a crucial role in society and daily life, as the functioning and durability of roads can significantly impact a nation's economic development. In the whole life cycle of the road, the emergence of disease is unavoidable, so it is necessary to adopt relevant technical means to deal with the disease. This study comprehensively reviews the advancements in computer vision, artificial intelligence, and mobile robotics in the road domain and examines their progress and applications in road detection, diagnosis, and treatment, especially asphalt roads. Specifically, it analyzes the research progress in detecting and diagnosing surface and internal road distress and related techniques and algorithms are compared. In addition, also introduces various road governance technologies, including automated repairs, intelligent construction, and path planning for crack sealing. Despite their proven effectiveness in detecting road distress, analyzing diagnoses, and planning maintenance, these technologies still confront challenges in data collection, parameter optimization, model portability, system accuracy, robustness, and real-time performance. Consequently, the integration of multidisciplinary technologies is imperative to enable the development of an integrated approach that includes road detection, diagnosis, and treatment. This paper addresses the challenges of precise defect detection, condition assessment, and unmanned construction. At the same time, the efficiency of labor liberation and road maintenance is achieved, and the automation level of the road engineering industry is improved.

The application of reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) on asphalt pavement can reduce the asphalt paving cost, conserve energy and protect the environment. However, the use of high contents of RAP and RAS in asphalt pavement may lead to durability issues, especially the fatigue cracking and thermal cracking. It is necessary to conduct a series of analyses on asphalt mixtures containing high RAP and RAS, and seek methods to enhance their long-term performance. This paper provides a comprehensive over-view of the long-term performance of recycled asphalt mixtures containing high contents of RAP and RAS. The findings in this research show that rutting resistance of high recycled asphalt mixtures is not a concern, whereas their resistance to fatigue and thermal cracking is not conclusive. Recycling agents can be used to improve the thermal cracking resistance of high recycled asphalt mixtures. An optimum decision on recycling agents will improve the durability properties of high recycled asphalt mixtures. It is recommended that to use a balanced mixture design approach with testing of the blended asphalt binders will provide better understanding of long-term performance of recycled asphalt mixtures containing high RAP and RAS.

This study aims to quantify the susceptibility of granular materials used in pavements to changes in moisture content and propose a correlation model to incorporate this susceptibility into seasonal analyses. The fines content and the percentage of fractured coarse aggregates were identified as direct indicators of the resilient modulus susceptibility to changes in water content. The results showed that the percentage of fractured coarse aggregates particles (FR) has a more significant impact on the resilient modulus (Er) of crushed granular materials used in pavement construction than the combined indicator of the fines content and sample volumetrics (n_f). Crushed granular materials with a higher percentage of fractured coarse aggregates are relatively insensitive to changes in the degree of saturation, but become more sensitive as the fine fraction porosity decreases. An adjusted model was proposed based on the existing formulation, but considers a complex parameter to describe and adjust the sensitivity of base granular materials to variations in moisture content with respect to fabrication characteristics, fines content and volumetric properties. The model shows that the variation of Er values is below ±10% for fully crushed granular materials. However, it reaches approximately ±12% for materials with 75% of crushed coarse aggregates and +40% and −25% for materials with FR ​= ​50%. This model could help select good aggregates characteristics and adjust grain-size distribution for environments where significant moisture content variations can occur in the pavement system, such as in the Province of Quebec (Canada). As it is based on parameters that can be easily determined or estimated, it also represents a valuable tool for detailed design and analysis that can consider material characteristics.

This paper reviews works on the dynamic analysis of flexible and rigid pavements under moving vehicles on the basis of continuum-based plane strain models and linear theories. The purpose of this review is to provide information about the existing works on the subject, critically discuss them and make suggestions for further research. The reviewed papers are presented on the basis of the various models for pavement-vehicle systems and the various methods for dynamically analyzing these systems. Flexible pavements are modeled by a homogeneous or layered half-plane with isotropic or anisotropic and linear elastic, viscoelastic or poroelastic material behavior. Rigid pavements are modeled by a beam or plate on a homogeneous or layered half-plane with material properties like the ones for flexible pavements. The vehicles are modeled as concentrated or distributed over a finite area loads moving with constant or time dependent speed. The above pavement-vehicle models are dynamically analyzed by analytical, analytical/numerical or purely numerical methods working in the time or frequency domain. Representative examples are presented to illustrate the models and methods of analysis, demonstrate their merits and assess the effects of the various parameters on pavement response. The paper closes with conclusions and suggestions for further research in the area. The significance of this research effort has to do with the presentation of the existing literature on the subject in a critical and easy to understand way with the aid of representative examples and the identification of new research areas.

E-ticketing, which has been promoted by the Federal Highway Administration (FHWA) “every day counts” (EDC) initiative, utilizes software applications to digitally track and store information regarding highway construction materials paid by state transportation agencies (STAs) by weight in unit bid contract structures. STAs often face implementation barriers such as institutional inertia, or the resistance by stakeholders to adopt changes from the status quo, including new technologies. The purpose of this paper is to determine the progression of STA e-ticketing policy adoption, specifically with a focus on asphalt paving operations, due to the COVID-19 pandemic. To accomplish this research effort, previous FHWA data, National Cooperative Highway Research Program (NCHRP) data, and other literatures are reviewed to determine an implementation baseline. Additional data is collected from the American Association of State Highway and Transportation Officials Committee on Construction to gain current feedback from STAs and their highway contractor partners after the COVID-19 pandemic. Additionally, a case study featuring the Kentucky Transportation Cabinet (KYTC), the Kentucky Association of Highway Contractors (KAHC), and the Plantmix Asphalt Industry of Kentucky (PAIKY) is performed to provide more in-depth analysis. The major finding includes a statistically significant result indicating increased implementation of e-ticketing for asphalt operations within the last two years, along with noting benefits including employee safety, task loading, and project documentation along with concerns regarding cellular connectivity and procurement responsibilities. These findings indicate the importance of STAs investing in partnership with contractors to improve stakeholder buy-in before proceeding towards e-ticketing adoption.

In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs, this study presents an intelligent strategy for extracting road cracks. This methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of images. The study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously. A convolutional neural network is utilized to extract cracks from the panoramic sequence image. The extracted sequence image is then aligned with the laser point cloud, enabling the assignment of RGB information to the vehicle-mounted three dimensional (3D) point cloud and location information to the two dimensional (2D) panoramic image. Additionally, a threshold value is set based on the crack elevation change to extract the aligned roadway point cloud. The three-dimensional data pertaining to the cracks can be acquired. The experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road cracks. The utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road cracks. This approach exhibits superior accuracy when compared to conventional methods. Moreover, it facilitates rapid and accurate identification and localization of road cracks, thereby playing a crucial role in ensuring road maintenance and traffic safety. Consequently, this technique finds extensive application in the domains of intelligent transportation and urbanization development. The technology exhibits significant promise for use in the domains of intelligent transportation and city development.