Journal of Road Engineering最新文献

The American Association of State Highway and Transportation Officials Mechanistic-Empirical Pavement Design Guide (AASHTO M-E) offers an opportunity to design more economical and sustainable high-volume rigid pavements compared to conventional design guidelines. It is achieved through optimizing pavement structural and thickness design under specified climate and traffic conditions using advanced M-E principles, thereby minimizing economic costs and environmental impact. However, the implementation of AASHTO M-E design for low-volume concrete pavements using AASHTOWare Pavement ME Design (Pavement ME) software is often overly conservative. This is because Pavement ME specifies the minimum design thickness of concrete slab as 152.4 ​mm (6 in.). This paper introduces a novel extension of the AASHTO M-E framework for the design of low-volume joint plain concrete pavements (JPCPs) without modification of Pavement ME. It utilizes multi-gene genetic programming (MGGP)-based computational models to obtain rapid solutions for JPCP damage accumulation and long-term performance analyses. The developed MGGP models simulate the fatigue damage and differential energy accumulations. This permits the prediction of transverse cracking and joint faulting for a wide range of design input parameters and axle spectrum. The developed MGGP-based models match Pavement ME-predicted cracking and faulting for rigid pavements with conventional concrete slab thicknesses and enable rational extrapolation of performance prediction for thinner JPCPs. This paper demonstrates how the developed computational model enables sustainable low-volume pavement design using optimized ME solutions for Pittsburgh, PA, conditions.

The inherent self-healing ability of asphalt is insufficient and fails to timely repair the cracks due to the combined effect of temperature variation, air oxidation, ultraviolet exposure and traffic loading. Rejuvenator encapsulation based on self-healing asphalt is a green sustainable preventive maintenance technology for asphalt pavement. During the last decade, rejuvenator encapsulation for asphalt self-healing has been a research hotspot and calcium alginate hydrogels encapsulating rejuvenator is a promising self-healing technology. Hence, this review sheds light on the recent advances of calcium alginate hydrogels encapsulating asphalt rejuvenator including self-healing capsules and fibers. The synthesis methods of calcium alginate capsules and fibers containing rejuvenator were elaborately introduced, and their surface morphology, interior structure, mechanical strength, thermal stability, rejuvenator content, distribution and survival in asphalt materials were systematically analyzed. Besides, the effect of capsules and fiber on the mechanical property and pavement performance of asphalt concrete were explored. Additionally, a comprehensive review about the effect of calcium alginate capsules and fibers on self-healing ability of asphalt materials were presented, and the rejuvenator release mechanism and release ratio of them in asphalt mixtures were expounded. In a nutshell, this review aims at highlighting the current research achievements on alginate capsules and fibers containing rejuvenator in asphalt materials, and inspiring enhanced self-healing methods for smart and sustainable maintenance of asphalt pavement.

Accurate prediction of performance decay law is an important basis for long-term planning of maintenance strategy. The statistical regression prediction model is the most widely employed method to calculate pavement performance due to its advantages such as the small amount of calculation and good accuracy, but the traditional prediction model seems not applicable to the high maintenance level areas with excellent pavement conditions. In this paper, the service life and the cumulative number of the axle load were determined as the independent variables of prediction models of pavement performance. The pavement condition index (PCI) and rutting depth index (RDI) were selected as maintenance decision control indexes to establish the unified prediction model of PCI and RDI respectively by applying the cosine deterioration equation. Results reveal that the deterioration law of PCI presents an anti-S type or concave type and the deterioration law of RDI shows an obvious concave type. The prediction model proposed in this study added the pavement maintenance standard factor d, which brings the model parameter α (reflecting the road life) and the deterioration equations are more applicable than the traditional standard equations. It is found that the fitting effects of PCI and RDI prediction models with different traffic grades are relatively similar to the actual service state of the pavements.

Bio-based and nature-inspired solutions have been investigated recently to develop sustainable, resilient, and durable construction including but not limited to roadway infrastructures. This paper reviews state-of-the-art studies on self-healing, self-cleaning and self-rejuvenating asphalt, and concrete construction. This review draws three conclusions. (1) Self-healing construction materials have the potential to significantly extend the service life of construction elements. Urban and industrial wastes such as food waste, biomass, metals have been used to create self-healing construction materials that are more environmentally friendly. (2) Self-cleaning construction materials not only remove pollution by repelling water on their superhydrophobic surface, but also cut building and infrastructure maintenance costs, while improving cities' air quality by degrading pollutants such as NO_x. Pavement engineers have exploited self-cleaning characteristic to facilitate the de-icing of pavements and lengthening the service life of pavements. (3) Self-rejuvenating materials including bio-oils can revitalize materials and delay aging; bio-oils can also be used to make bio-binders, thereby reducing the need for petroleum-based binders. The optimum concentration of bio-oil for asphalt modification depends on the chemical structure of oils. Still, regardless of dosage, self-rejuvenating binders improve asphalt workability and performance at low temperatures and increase the resistance of the asphalt mix to fatigue and cracking. This review also identified critical research gaps, including (1) the lack of a reliable, unified, and standard method to accurately measure construction materials’ self-healing, self-cleaning and self-rejuvenating properties; (2) the lack of long-term field performance data to conduct comprehensive life cycle assessment and life cycle analysis; (3) the lack of accurate technoeconomic analysis to facilitate market entry of abovementioned solutions. Addressing these gaps and determining contribution of nature-inspired and bio-based technologies to a carbon neutral economy along with issuing carbon certificates can facilitate the widespread application of these technologies while promoting resource conservation and sustainability.

Magnesium phosphate cement (MPC) cementitious material is a phosphate cement-based material with strength formed by a serious of acid-base neutralization reactions among magnesium oxide, phosphate retarder and water, which has a high early strength and a broad application prospect in the field of pavement rehabilitation. This review collects and organizes the latest progress in the field of research on the influencing factors of mechanical properties of magnesium phosphate cementitious materials worldwide in recent years, and discusses the possibilities of application in airport engineering.

The type of phosphate has a great influence on the reaction products, and the strength of the reaction products of ammonium salt is higher. Borax is the most commonly used retarder, and the retarding effect is related to the ratio of boron to magnesium. However, borax retarders have an adverse effect on the strength of MPC. In terms of the influence of mineral admixtures on the properties of MPC, fly ash, silica fume and metakaolin, as common mineral admixtures, have a positive influence on the mechanical properties of MPC, but the mechanism and degree of the influence of the three materials on the strength of MPC are slightly different; Aggregates can also improve the volume stability and mechanical properties of MPC by forming skeleton structure and slowing down the exothermic reaction. In fiber reinforced MPC matrix, steel fiber is the most widely used and the bonding performance between special-shaped steel fiber and MPC matrix is higher than that of straight fiber; basalt fiber has also been proved to be used to improve the mechanical properties of MPC system.

Asphalt binder is inevitably aged by ultraviolet (UV) light during its service period. UV ageing can significantly decrease the technical properties of asphalt binder. The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs, such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance. Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing, and the UV light parameters effect on the ageing rate of asphalt binder. However, the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions, and the UV ageing mechanism of asphalt binder is not very clear. Therefore, it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders. This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders. With the increase of UV ageing time, the UV ageing of asphalt binder develops gradually from the surface to inner part. There are various methods, such as low-penetration grade asphalt, less air void ratio, UV stabilizers and UV light absorbers, that can improve the UV ageing resistance of asphalt binders. A new theory of sensitive wavelengths of asphalt UV ageing is proposed, which can enrich the basic theory of asphalt UV ageing. Depending on this theory, different wavelengths of UV light have different ageing effects on asphalt binder. The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed, and may have better improvement effect on the anti-UV ageing performance of asphalt binder.

With the continuous development of bridge and tunnel construction technologies, large-scale sea-crossing bridges and tunnels have gradually become the preferred choice for regional traffic. The construction technology of Hong Kong-Zhuhai-Macau Bridge (HZMB), one of the most representative sea-crossing passageways, is instructive for the construction of other large sea-crossing infrastructures. At present, the pavement design method of sea-crossing passageways lacks pertinence as it still refers to specifications for design of common pavement. Therefore, it is necessary to consider the bridge and tunnel pavement of HZMB as a typical example to analyze key technical problems encountered in its design, construction and operation. Novel solutions for material selection and structural design built upon the analysis of such critical problems should thus follow up. Based on comprehensive literature research, it can be found that environmental variability, tunnel closure, structural differential settlement and expansion deformation are the key technical problems faced by pavement of sea-crossing passageways. In view of the environmental variability, the steel deck-paving material and structure design of GMA-10 + SMA-13 is innovatively proposed. As for the closure of immersed tube tunnel, warm-mix flame retardant asphalt mixture is used to control pavement design through key indexes such as temperature and limit oxygen index. Regarding the deformation of immersed pipe joints, BJ200 asphalt seamless expansion joint material is introduced, which effectively satisfies the multi-directional deformation between pipe joints and ensures the smoothness of the road surface and driving comfort. For segmental joints, double-layer waterproof-coiled material is used to effectively prevent reflective cracks while ensuring the continuity of asphalt concrete pavement. Therefore, this paper provides a panel of ideas and methods for the pavement design of the same type of sea-crossing passageways.

To understand the research status of asphalt pavement texture, the related achievements and progress of pavement surface texture were systematically sorted out from three aspects: the characterization of pavement surface texture, the texture measurement and evaluation, and the relationship between texture and the skid resistance. Based on the statistical geometric characteristics, the spectral characteristics, the fractal characteristics and the multifractal characteristics, the characteristics of pavement texture were discussed. The test methods of pavement texture were divided into two categories: direct measurement methods and indirect measurement methods. The advantages and disadvantages of each measurement method were summarized. The effects of macro-texture and micro-texture on asphalt pavement were discussed, respectively. The relationship between texture and skid resistance was studied. This review shows that multifractal theory should be further studied from the aspect of road engineering. High-precision non-contact integrated detection technology should be further studied to meet the needs of complex testing environments. The method of finite element numerical simulation has potential for the analysis of pavement skid resistance. In addition, methods such as big data analysis, neural network, and deep learning should be studied to achieve the intelligent perception and management of the whole state of skid resistance prediction.

The conventional flexible pavements have been constructed such that the stiffness of the layer reduces with depth. The crust thickness becomes significantly high for heavy traffic corridors resulting in the consumption of large quantities of construction materials and also increasing environmental pollution. Inverted pavements with the aggregate interlayer (AIL) or stress absorbing membrane interlayer (SAMI) are considered to be one of the alternatives for thick conventional flexible pavements for heavy traffic corridors. The AIL or SAMI is placed between a stiff cement-treated base and asphalt concrete layer to function as crack relief layers. This change in the composition alters the behaviour of inverted pavements compared to the conventional flexible pavements. On the other hand, wide-base tires are being increasingly preferred by trucking industries due to increased fuel economy and cargo capacity. However, the effect of wide-base tires on the performance of inverted pavements is yet to be investigated. In this study, the 3D finite element (FE) models of inverted pavements considering different crack relief layers were developed, and load from dual-wheel and wide-base tires were applied. The stress-strain evolution in the various layers of inverted pavements was investigated and discussed in this study. The results indicated the higher stress and strains due to wide base tires compared to the dual-wheel assembly. Further, pavement with SAMI was found to result in lower stress and strains in the asphalt concrete layer compared to AIL pavements.

In recent years, various information and communication technology (ICT) devices measuring three-dimensional (3D) point cloud data have been developed and widely used for the application of pavement surface investigation. However, ICT devices have generally been developed not only for measuring road surface profiles but for various geo-reference point clouds. In this background, the validation of surface profiles acquired with ICT devices fulfils an important role in proving the reliability of measurement result composed by point clouds. This study proposes a wavelet transform agreement (WTA) which involves a normalization factor of profile amplitude for further improvement in the wavelet-based coherence technique. The WTA analysis allows evaluating similarity/dissimilarity of two profiles considering both the location and wavelength simultaneously. For this purpose, a terrestrial laser scanner (TLS), a mobile mapping system (MMS), and an unmanned aerial vehicle (UAV) are employed to prove the advantage of WTA in practical applications. As a result, the advantages of WTA analysis are clearly recognized in the optimization for the measurement interval of TLS, the multi-line measurement of MMS for ride quality improvement of a pavement, and the efficient operation of UAV in terms of the flight altitude. This paper also shows the identification of aging development for surface roughness over time in terms of locations and wavelengths. These findings help not only to guarantee the accuracy of profile measurements but to realize the sophisticated way of using 3D point clouds acquired with ICT devices. The outcomes of this study contribute to the increase of productivity for pavement works with improving the quality of surface profile measurement.