Yuhong Wang

• Doctor of Philosophy
• Professor at The Hong Kong Polytechnic University

Contrary to the conventional linear viscoelastic analysis, asphalt binder’s response in the non-linear viscoelastic (NLVE) domain can potentially reveal more complex aspects of its micromorphology. This research aimed at investigating the evolution of the NLVE and micromorphological properties of styrene–butadiene–styrene (SBS)-modified asphalt bin...

Tire-pavement noise is a major contributor to traffic noise pollution, impacting human health and well-being. The advent of 3D printing and prefabrication technologies makes it feasible to economically produce delicate concrete pavement textures for noise mitigation. However, relationships between the noise and texture characteristics (e.g., cavity...

This study aims to investigate the effects of styrene-butadiene-styrene (SBS) polymer structure on the physicochemical and performance-related properties of modified asphalt binders, with the consideration of two other influencing factors: polymer content and aging condition. The factorial experimental design involves three types of SBS polymers (d...

This study aims to investigate the effects of styrene-butadiene-styrene (SBS) polymer structure on the physico-chemical and performance-related properties of modified asphalt binders, with the consideration of two other influencing factors: polymer content and aging condition. The factorial experimental design involves three types of SBS polymers (...

Intelligent reflecting surface (IRS) is considered a promising solution to manipulate the radio frequency transmission environment in the sixth-generation (6 G) wireless systems. However, little attention was received by IRS-aided localization techniques. Among range-free wireless localization strategies, received signal strength indicator (RSSI) f...

River restoration or improvement is widely practiced in cities around the world to promote sustainable urban development. However, post-project evaluation is not commonly performed, and even less evaluated is the social impacts of river restoration. Based on three recently restored river channels in Hong Kong, this study evaluated water quality, bi...

The intelligent transportation system (ITS) is committed to ensuring safe and effective next-generation traffic throughout a city. However, such efficient operation on urban traffic networks needs the support of big traffic data, especially Turning Movement Counts (TMC) at intersections. Generally, TMC data are more challenging to collect due to la...

Reducing greenhouse gas emissions has turned into a pillar of climate change mitigation. Truck platooning is proposed as a strategy to lower emissions from vehicles on roads. However, the potential interactive impacts of this technology on road infrastructure emissions remain unclear. Here, we evaluate the decarbonization effects of truck platoonin...

Urban greenspace is an effective approach to reducing urban heat island (UHI) effects and providing comfort to the nearby occupants. In this study, a multiscale evaluation of the cooling effect of different types of greenspaces was conducted. Studies were conducted among four typical urban communities in two densely urbanized cities - Hong Kong and...

River systems worldwide are severely degraded due to diverse threats. River restoration aiming to reverse negative impacts has become a priority strategy for enhancing social benefits and river ecosystems in urban development. River restoration projects provide multiple ecosystem services to human beings, and social benefits derived from cultural s...

Polyurethane (PU) is a synthetic polymeric material with excellent mechanical properties and chemical designability. An in-depth understanding of the synergetic effect between polyurethane and asphalt binder is needed to produce durable PU-modified asphalt paving materials. This study focuses on the physicochemical changes, the states of in situ sy...

The urban heat island (UHI) phenomenon is becoming increasingly severe due to unprecedented urbanization and global warming paces. The increasing heat stress threatens the environment, the health of residents, and also the city the walkability. However, greenspace can generate a cooling effect to mitigate the UHI. To gain a better understanding of...

Asphalt binder is prone to aging in usage conditions. Although aging an asphalt binder using a pressure aging vessel (PAV) is a popular method to simulate the long-term aging of the binder, questions have been raised about the accuracy of this method. This research is focused on (i) examining the detailed physicochemical aging processes of asphalt...

Due to increasing precipitation intensity, rising sea level, and land development, urban flooding has become a major issue in many places around the world. This research aims to develop underground storage tanks (USTs) using fiber-reinforced polymer (FRP) materials for stormwater detention, storage, and reuse. The USTs are intended to be placed und...

Urban flooding has become one of the major issues in many cities around the world, due to rising sea level, increasing precipitation intensity, and land development. This research aims at the development of underground storage tanks (USTs) using fiber-reinforced plastic (FRP) materials for stormwater detention, storage, and reuse. The USTs are prop...

The oxidative aging of asphalt binder affects the long-term performance of flexible pavement. Apart from the intrinsic property of asphalt binder, binder aging in an asphalt mixture is also affected by the mixture’s oxygen transport efficiency, which can be characterized by the oxygen diffusion coefficient. In this study, the diffusion coefficients...

Growing concerns on excessive urban heat call for better approaches to modeling urban thermal environment and developing effective mitigation strategies. A hybrid model integrating the geographically weighted regression (GWR) and deep neural network (DNN) was developed to estimate land surface temperature (LST). This model was compared with three o...

Fatigue performance evaluation on asphalt mixture provides an essential reference for asphalt mixture design and pavement structure design. Laboratory fatigue test has been widely used by researchers and engineers to assess the fatigue performance of asphalt mixture, due to its low cost, high efficiency, and strong operability. To ensure performanc...

Walkable cities are critically important for promoting the well-being of urban residents and reducing air pollution and greenhouse gas (GHG) emissions. The walkability of a city is affected by its thermal environment. To gain a better understanding on how the urban thermal environment affects walkability, this study investigated the relationships b...

Multilabel classification (MLC) is a challenging task in real-world applications, such as project document classification which led us to conduct this research. In the past decade, deep neural networks (DNNs) have been explored in MLC due to their flexibility in dealing with annotated data. However, DNN-based MLC still suffers many problems. Two cr...

The realistic structure of bitumen at the microscopic level, although of great value to researchers and practitioners, has not been thoroughly and quantitatively examined. This study characterized twelve bitumen samples of various origins and aging states by fraction analysis, scanning transmission electron microscope (STEM), and gel permeation chr...

Although various rating systems have been developed to promote sustainable development in roadway construction, sustainability evaluation from the perspective of safeguarding workers’ health is currently lacking. Three approaches were used in the study to identify and prioritize key health hazards to workers in roadway construction, including bibli...

Asphalt binder is a widely used engineering material. It is essentially a nanomaterial with colloidal particles suspended in an oily medium. As asphalt binder ages, the colloidal particles are subject to fundamental physicochemical changes such as agglomeration, which is translated into dramatic engineering property changes of the asphalt binder. I...

Accurate localization is a critically important issue for autonomous vehicles as it is closely related to the safety and efficiency of autonomous driving. However, current technologies for autonomous vehicle localization face many challenges. To provide accurate and robust localization services to autonomous vehicles, we propose a novel solution by...

Tests on asphalt binder are typically performed in its linear viscoelastic (LVE) range. In this research, the rheological properties of neat and styrene–butadiene-styrene (SBS)-modified asphalt binders were examined from 0.01% to 1000% at a high usage temperature, and focus was placed on their non-linear viscoelastic (NLVE) behaviours. Experimental...

Numerous studies have been conducted to evaluate the property variations of asphalt binders from different sources and their property evolutions during the aging process. Most existing studies, however, are focused on asphalt binder properties at the macroscopic level. The fundamental mechanisms that drive the property variations and evolutions are...

Substantial amount of resources is consumed by pavement systems, which have resulted considerable environmental impacts. Understanding the environmental impacts would provide opportunity for reducing resource consumption and informing decision-makers in the process of designing sustainable pavement. There is a lacking of comprehensive and comparati...

River restoration projects are widely implemented around the world. Such projects are usually complicated endeavors. Engineering, environmental, and social impacts must be considered under various constraints. Gaining lessons from existing projects would be valuable in new project planning. However, because such projects vary greatly in objectives...

This research analyzes the fatigue behaviours of asphalt mixture under haversine wave and two more realistic loading waveforms induced by the single axle and tandem axles, based on the pseudo-strain-based approaches. It is found that the fatigue lives of asphalt mixture under the single-axle wave are higher than those under the haversine wave, whil...

One of popular models to describe mechanical behavior of asphalt binder is the Generalized Maxwell Model (GMM), which is analogized as a large number of springs and dashpots connected in a parallel fashion. Theoretically, the continuous relaxation spectrum of GMM of a particular asphalt binder is unique and reflects its fundamental physicochemical...

Asphalt binder is a widely used engineering material. It is essentially a nanomaterial with colloidal particles suspended in an oily medium. As asphalt binder ages, the colloidal particles are subject to fundamental physicochemical changes such as agglomeration, which is translated into dramatic engineering property changes of the asphalt binder. I...

Different groups of people are exposed to respirable particles in recycling asphalt pavement materials. In evaluating the health issues of such particles posed to construction workers, existing studies mainly focus on respirable crystalline silica but rarely address the organic fractions. In this study, respirable particles in reclaimed asphalt pav...

Textures of concrete pavements not only provide essential functions for vehicles but also affect the durability of pavements. The development of 3D printing and prefabrication technologies enables the manufacturing of intricate surface textures at the industrial scale. Such textures can provide excellent functions such as high skid resistance and l...

Although a large number of river restoration projects have been implemented around the world, quantitative outcomes of the projects are often not well documented. The main purpose of this study is to assess changes in water quality of two completed river restoration projects, which convert heavily channelized streams into more natural conditions us...

Fatigue cracking is one of the main distress modes of highway asphalt pavements. In laboratory fatigue tests, haversine or sinusoidal loading waves are commonly applied to characterize the fatigue performance of asphalt mixture samples. The strain wave in field asphalt layer under a moving axle load, however, is noticeably different from the havers...

In this study, dynamic moduli of asphalt mixtures under uniaxial compression (UC), indirect tension (IDT) and four-point bending (4PB) loading modes were tested and incorporated in the MEPDG procedure to predict the pavement responses. The field responses from a full-scale asphalt pavement were used to evaluate the prediction accuracies of three ty...

Deteriorating water quality leads to the freshwater biodiversity crisis. The interrelationships among water quality parameters and the relationships between these parameters and taxa groups are complicated in affecting biodiversity. Never-theless, due to the limited types of Internet of Things (IoT) sensors available on the market, a large number o...

The effects of six heat mitigation strategies on thermal environment, thermal comfort, and walkability are evaluated. Thermal environment is simulated using a micro-scale computational fluid dynamic (CFD) model—ENVI-met. Thermal comfort is quantified with the Universal Thermal Climate Index (UTCI), which is linked to walkability through agent-based...

The master curves of complex shear modulus |G∗(ω)| and phase angle δ(ω) of asphalt binder provide its important rheological information. Although many studies have been performed to develop prediction models of |G∗(ω)|, the determination methods often focus on fitting them with experimental data of the modulus. The intrinsic relationships between |...

The world is experiencing a rapid loss in the biodiversity of pollinator insects. Habitat segmentation caused by infrastructures is one of the contributing factors. To improve the habitat connectivity of pollinator insects, it is proposed in this study to build green corridors for pollinators over linear infrastructures such as highways. In the con...

As global biodiversity is being lost at an alarming rate, urban green infrastructures can potentially play a beneficial role in biodiversity conservation. Such infrastructures are produced and managed by practitioners. Analogous to engineering inspection, the ecological performance of such infrastructures also needs to be evaluated: not only for as...

The world is experiencing a rapid loss in the biodiversity of pollinator insects. Habitat segmentation caused by infrastructures is one of the contributing factors. To improve the habitat connectivity of pollinator insects, it is proposed in this study to build green corridors for pollinators over linear infrastructures such as highways. In the con...

Over the years, different hypotheses and speculations have been developed on asphaltenes, but their presence in asphalt has never been directly observed. In this study, asphaltenes in nine types of asphalt that vary in crude oil source and aging states are examined through scanning transmission electron microscopy (STEM) and atomic force microscopy...

Global warming is an increasingly serious issue faced by human beings. As one of the largest contributors to global CO2 emissions, the construction industry plays a significant role in combating global warming and achieving sustainable development. This study aimed to compare the CO2 emissions in the construction industry around the world and analy...

Associations between polymer morphology and the properties of polymer-modified asphalt (PMA) have been widely reported. Fluorescence microscopy (FM) plays a key role in analyzing the morphology of polymers in PMA. However, two-dimensional (2D) fluorescence images may not reveal the true nature of polymer phase in PMA, because the image is a project...

Gel permeation chromatography (GPC) is commonly used to study the aging and rejuvenation behaviours of asphalt binders, as the sizes of molecules and microstructures in asphalt binders change in such processes. The filtration procedure in preparing GPC specimens, however, may filter out some large-size microstructures in asphalt, making the measure...

The surface temperature distribution of buildings and infrastructures is a key piece of information in the analysis of built environments especially in urban areas. It not only helps understand and model the thermal performance of buildings, but also reveal the thermal environments exposed by pedestrians. The information may further help improve th...

The microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanos...

Urban heat island (UHI) effect is a remarkable phenomenon in urban climate. This study analyzed the patterns of land surface temperature (LST) and land use/land cover (LULC) in Hong Kong. Geographical Information System (GIS) and statistical methods were used for analysis. The results indicate that LST is significantly affected by LULC types. The o...

Effective use of massive construction site images and videos requires an efficient storage and retrieval method. However, significant portions of the image regions contain little useful information to project engineers and managers. To reduce resource waste in data storage and retrieval, we developed a new semantic region detection approach using t...

Styrene-butadiene block copolymer (SBS) is a widely used as a modifier for improving asphalt binder properties. However, due to the lack of understanding on binder property changes during aging and sample preparation, quality control and quality assurance (QC/QA) measures are seldom applied to SBS modified asphalt binders in pavement mixtures. In t...

Hot-mix asphalt pavement recycling is widely practiced for its economic and environmental benefits. Existing studies are mainly focused on the engineering properties of reclaimed asphalt pavement (RAP) materials, without considering their impacts on the generated asphalt fumes—a widely recognized environmental hazard. The effects of using RAP on as...

Climatological reports demonstrate a clear trend of more frequent occurrence of extreme weathers. Flooding caused by heavy rains severely affects highway pavement performance in many coastal regions. As the trend of climate change continues, highway pavements in these regions will become more vulnerable to flooding. At present, however, pavement de...

This study examines the influence of different ageing conditions on the commonly interested chemical properties of asphalt binders, including the oxygenated functional groups and Corbett fractions. Three ageing conditions were applied to five types of asphalt binders, which were tested at different time points during the ageing processes. Changes i...

In order to improve the water absorbency of natural silk and extend its applications in wider areas, silk fibroin (SF)-based fibers were prepared by coaxial wet spinning. Using a custom-made wet spinning device with coaxial spinneret, continuous core–sheath fibers were finally obtained by adjusting the core dope into iota-carrageenan/polyacrylamide...

Conventional pavement, namely concrete and asphalt pavements, usually necessitate considerable energy inputs during construction. Due to increasing road coverage in cities and the impervious feature of conventional pavements, the heat island effect is becoming increasingly severe. Many environmental problems have appeared. Permeable pavements have...

High-temperature rheological properties of asphalt binders are important in asphalt mixture production and compaction. In this study, the high-temperature rheological properties of asphalt binders with polymeric, warm-mix, and rubber particulate additives were examined at different temperatures, shear rates, and shear modes. Most of the tests were...

Asphalt fumes generated in pavement construction have been extensively studied from the perspective of occupational health. In this paper, they are examined from the perspective of material and construction. Asphalt binders from different sources were used to create standard mixtures. An asphalt fume generation and collection system was designed an...

Permeable pavements facilitate the infiltration and percolation of stormwater and are therefore increasingly used to mitigate the growing risk of urban flooding. Although extensive research has been conducted on the hydraulic and mechanical properties of Porous Asphalt (PA), the durability is still a main obstacle inhibiting the widespread applicat...

The dynamic modulus (E*) of asphalt mixtures is an important parameter in pavement design and analysis. Although the E* values of freshly prepared hot-mix asphalt (HMA) mixtures can be conveniently determined through laboratory tests, the E* values of field pavements continuously evolve as asphalt binder ages, and hence are difficult to determine....

In asphalt pavement recycling, rejuvenators are often used to improve the engineering properties of asphalt binders in old pavements. A key question interested by practitioners is if the rejuvenators simply dilute the microstructures formed in aged asphalt binders or dissolve them. The latter is clearly preferred in effective asphalt pavement recyc...

To fully understand the filler reinforcement mechanism in asphalt mastic, molecular dynamic (MD) simulation was adopted to explore the effect of mineral filler on the structural, thermodynamic and mechanical properties of asphalt mastic. An asphalt/silica nanoparticle composite system that consisted of silica nanoparticles and a 12-components combi...

Soils containing rich soluble salts are widely available. Their behaviors as pavement subgrade depend on the types and compositions of the salts, local climate, and hydrogeological conditions. In this study, various amounts of Portland cement, lime, and their combinations were used to treat a chloride-dominant saline soil. The engineering propertie...

Reliable assessment of asphalt binder aging is important for material selection and the prediction of asphalt property changes in field pavements. The apparent property changes of asphalt binder with aging, however, are affected by aging conditions. In this study, three aging treatment methods were applied to five types of asphalt binders, and the...

Workers involved in asphalt pavement construction are exposed to asphalt fumes. The adverse health effects of asphalt fumes have long been recognized; however, there is still a lack of consistent and systematic approaches to measurement, assessment, and mitigation of asphalt fume exposures. This study reviewed the current status of research and pra...

Produced with fine crumb rubber (CR) particles and at demanding conditions, Terminal Blend (TB) asphalt binder is an alternative approach to incorporating CR from scrap tires into asphalt binders. It offers the advantages of convenient transportation, storage, and usage at asphalt mixture plants. In the study as presented in this paper, Sasobit® an...

The oxidative aging of asphalt binder in asphalt mixture is a key factor that affects the long-term durability of asphalt pavement. The aging susceptibility of an asphalt mixture is dependent on oxygen transport and consumption in the mixture. In this study, an apparatus was developed to measure oxygen diffusion and consumption in compacted asphalt...