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The present article deals with the optimization of additives used to improve penetration resistance of Himalayan soil and designing the pavement thickness. Eggshell powder, polypropylene fiber and sodium chloride were used as additives in a fine-grained soil for improvement in soil properties as a subgrade material. Optimization of additives was done using Taguchi method and MINITAB 21 software was employed for the analytical analysis of the responses obtained from the laboratory tests. The test results showed that the additives have potential for improvement in penetration resistance of fine-grained soil by 2.26 and 2.0 times that of untreated soil under unsoaked and soaked conditions respectively leading to considerable reduction in pavement thickness. The correlations given by the US Army Corps of Engineers and Indian Road Congress were used for determining the pavement thickness. Pavement thickness offered by US Army Corps of Engineers method is less and misleading to consider for pavement construction, whereas Indian Road Congress method has proved far better by offering rational lateral dimension for designing Indian rural hilly roads. [ABSTRACT FROM AUTHOR]

In road engineering, road construction requires a large amount of natural aggregate; its substitution with recycled construction-solid-waste aggregate not only saves resources but also reduces the burden on the environment. The main components of construction solid waste are concrete blocks and brick slag; the breakability of the latter can affect the performance of mixed recycled aggregate, which hinders the use of construction solid waste in road engineering applications. To analyze the applicability of recycled construction-solid-waste aggregate containing brick slag aggregate in the subgrade layer, the effect of brick aggregate content on the CBR (California bearing ratio) and crushing value of mixed recycled aggregates was evaluated based on laboratory tests, and the field compaction quality of the recycled aggregates was analyzed. The results show that the 9.5–19 mm mixed recycled aggregate samples were crushed to a higher degree during the compaction process. A brick aggregate content less than 40% had little effect on the performance of mixed recycled construction-solid-waste aggregate. It is recommended to use a 22 t road roller for five passes (two weak vibrations + two strong vibrations + one weak vibration) at a speed of 3 km/h in the main compaction stage of the subgrade filling. [ABSTRACT FROM AUTHOR]

This article presents a systematic review of the most cutting-edge research on precast pavement technology for the first time. Firstly, precast pavement is divided into two categories, precast cement concrete pavement and precast carpeted flexible pavement, according to the application of precast technology in pavement engineering. Subsequently, the structural characteristics, advantages, and disadvantages of various precast pavement systems are compared and analyzed; technical problems in precast pavement systems are explained; and future development directions are identified. In addition, the text specifically mentions the great contribution of precast carpeted flexible pavement technology in reducing the harmful effects of asphalt fumes on humans and the environment. This work will promote the application of prefabrication in road engineering and provide suggestions and references for subsequent research. [ABSTRACT FROM AUTHOR]

The objective of this research is to enhance the high-temperature antirutting and antiaging characteristics of bioasphalt. In this study, silica fume (SF) was selected to modify bioasphalt. The dosage of bio-oil in bioasphalt was 5%, and the dosage of SF was 2%, 4%, 6%, 8%, and 10% of bioasphalt. The high- and low-temperature characteristics, aging resistance, and temperature sensitivity of Bio + SF were evaluated by temperature sweep (TS), the multiple stress creep recovery (MSCR) test, the bending beam rheology (BBR) test, and the viscosity test. Meanwhile, the road behavior of the Bio + SF mixture was evaluated using the rutting test, low-temperature bending beam test, freeze–thaw splitting test, and fatigue test. The experimental results showed that the dosage of SF could enhance the high-temperature rutting resistance, aging resistance, and temperature stability of bioasphalt. The higher the dosage of SF, the more significant the enhancement effect. However, incorporating SF weakened bioasphalt's low-temperature cracking resistance properties. When the SF dosage was less than 8%, the low-temperature cracking resistance of Bio + SF was still superior to that of matrix asphalt. Compared with matrix asphalt mixtures, the dynamic stability, destructive strain, freeze–thaw splitting strength ratio, and fatigue life of 5%Bio + 8%SF mixtures increased by 38.4%, 49.1%, 5.9%, and 68.9%, respectively. This study demonstrates that the development of SF-modified bioasphalt could meet the technical requirements of highway engineering. Using SF and bio-oil could decrease the consumption of natural resources and positively reduce environmental pollution. [ABSTRACT FROM AUTHOR]

Growing concern over the combustion cost and environment has made road engineers and scientists to explore the possible use of locally available materials for the construction of roads. The present study evaluated the strength and durability characteristics of five sites having locally available silty soils using lime and cement–sand stabilization technique. The test results showed that the cement–sand stabilization technique using 6% cement and 5% local sand resulted in higher strength and durability as compared to lime stabilization. There is also a significant increase in the value of the soaked California bearing ratio (CBR). As unconfined compressive strength (UCS) attained the threshold strength as prescribed by IRC SP 72 2015 for the granular sub-base (GSB) layer, by the use of sand cement stabilization, this technique of stabilization for local silty soils could be used for GSB for low volume road (LVR) construction. As observed from microstructural results which were performed by analysing SEM images, sand cement stabilisation leads to CSH gel and agglomerate formation thereby increasing strength and durability properties. The cost analysis for the replaced stabilized GSB layer showed that using sand–cement stabilization, the estimated cost can be reduced by 56% of the total cost as compared to the conventional method. [ABSTRACT FROM AUTHOR]

To comprehensively and objectively evaluate the actual safety condition in road and bridge engineering construction, the road and bridge engineering construction safety risk evaluation index system is constructed combined with the factors induced by emergencies in the road and bridge engineering construction process. Aiming at the dynamic uncertainty of road and bridge construction safety risk, using Fuzzy Set Theory and an improved similar aggregation method to determine the prior probabilities and conditional probabilities of network nodes, and then selecting the transition probabilities of nodes through expert opinions and incident reports, leading to the development of a dynamic evaluation model for safety risks in road and bridge engineering construction based on Fuzzy Dynamic Bayesian Network, this model can make the construction safety risk prediction result accurately. Taking the Hebi City Provincial Highway 304 reconstruction project as an example for analysis, the results indicate that the model can accurately predict the probability of changes in safety risks in road and bridge engineering construction. Additionally, it can identify critical risk factors and provide crucial supporting information for decision-makers to optimize risk management strategies. [ABSTRACT FROM AUTHOR]

The huge demand for sand and gravel resources in road engineering construction leads to excessive consumption of resources and environmental damage. Recycling waste concrete and industrial solid waste as a road material is a promising alternative. In order to explore the application of these solid wastes in the road base, this paper studies the effect of adding lithium slag activated by an alkaline activator, fly ash (FA) and a combination of the two on the compressive strength, splitting strength and shrinkage performance of recycled cement-stabilized macadam mixture (RCSM). The optimum content of recycled aggregate (RA), alkali-activated lithium slag (AALS) and FA in composite-improved RCSM was optimized using a response surface method (Box–Behnken), and the microscopic characteristics of the mixture were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the optimum dosage of AALS, FA and RA determined by the response surface method is 15%, 10% and 40%, respectively. Compared with the cement-stabilized macadam mixture (CSM) with 40% RA, the 28 d compressive strength and 28 d splitting strength of the composite-improved RCSM are increased by 26.8% and 22.9%, respectively, and the dry shrinkage coefficient and average temperature shrinkage coefficient are decreased by 25.8% and 14.8%, respectively. Microscopic tests show that AALS and FA participate in the hydration reaction, generate more hydrated silicate (C-S-H) and ettringite (AFt), refine pores, effectively improve the performance of the internal interface transition zone of the mixture, make the microstructure of the mixture denser, and improve the strength and shrinkage performance of RCSM. This study provides technical support for the reuse of resources and the sustainable development of road construction. [ABSTRACT FROM AUTHOR]

Aggregate particles migrate and rearrange their spatial positions during the compaction process. To analyze the migration law, an accurate method to track migration of particles is proposed using discrete-element simulation and experimental verification. First, the coarse aggregates were generated based on realistic aggregate shapes using a three-dimensional (3D) Blu-Ray scanner. Subsequently, the fine aggregates, ranging from 0.075 to 2.36 mm, and asphalt mastic were replaced with balls with a radius of 0.7 mm. Then the three-dimensional dynamic compaction models of asphalt mixture were established using the Superpave gyratory compaction method and Marshall impact compaction method. Next, the migration tracking test of particles was developed adopting particle marking, step-by-step compaction, and CT scanning. Finally, the accuracy and efficiency of the virtual models were validated using the experimental data from the migration tracking test. The results indicate that the established compaction models can accurately track the aggregates particles and measure the migration indexes. The compaction methods have a great influence on the migration behavior. The displacement of the particles for the Superpave gyratory compaction method is greater than that for the Marshall method, and the displacement is multidirectional, whereas the displacement of particles for the Marshall impact compaction method mainly are vertical. [ABSTRACT FROM AUTHOR]

The use of natural river silt treated as a 'waste material' has become the focus of research in the Yellow River flooded area, especially in the field of highway engineering. It is therefore of great significance to study the deformation and stiffness degradation of Yellow River silt (YRS) under long-term cyclic loads. To this end, a series of undrained cyclic triaxial tests on YRS for a large number of cycles (10 000) was carried out using a triaxial apparatus and the effects of confining pressure and cyclic stress ratio on the resilient strain of the YRS were explored. The critical cyclic stress and the critical cyclic stress ratio between the plastic shakedown state and incremental collapse state of the YRS were determined, and the modulus-softening behaviour of the YRS was assessed. The results of this study not only provide theoretical support for the long-term engineering performance of YRS, but also provide theoretical guidance for the cyclic response of all similar types of subgrade soils. [ABSTRACT FROM AUTHOR]

The as-built roughness, or smoothness obtained during pavement construction, plays an important role in road engineering since it serves as an indicator for both the level of service provided to users and the overall standard of construction quality. Being able to predict as-built roughness is therefore important for supporting pavement design and management decision making. An as-built IRI prediction model for asphalt overlays based on profile transformation was proposed in a previous study. The model, used as basis for this work, was developed for the case of wheeled pavers without automatic screed levelling. This study presents further development of the base prediction model, including the use of an automatic screed control system through a long-distance averaging mobile reference. Formulation of linear systems that constitute the model are presented for the case of a wheeled paver using contactless acoustic sensors set-up over a floating levelling beam attached to the paver. To calibrate the model, longitudinal profile data from the Long-Term Pavement Performance SPS-5 experiment was used, obtaining a mean error of 0.17 m/km for the predicted IRI. The results obtained demonstrate the potential of the proposed approach as a modelling alternative. [ABSTRACT FROM AUTHOR]

In this study, the variation of shear strength behavior and particle breakage (after shearing), as a function of moisture state and compaction level, is investigated for recycled concrete aggregate blended with recycled clay masonry. Recycled masonry was blended with concrete aggregate in percentages ranging from 0% to 30% by total weight. Tests include; basic engineering characteristics (particle size, modified compaction, hydraulic conductivity, and California Bearing Ratio, CBR) as well as unconsolidated undrained static triaxial testing. In triaxial tests, moisture levels ranged from 60% to 100% of optimum moisture content, but compaction levels ranged from 90% to 98% of maximum dry density. The hydraulic conductivity for blends is approximately 2x10-6 cm/s, which indicates a relatively low hydraulic conductivity. Results show a proportional linear relationship between the shear strength of blends and the level of compaction. Despite this, both apparent cohesion and shear strength exhibited reverse linear trends. As expected, more compaction effort resulted in more particle breakage. Strict control should be performed over the compaction process to achieve the required compaction level which resulting in pavement materials being stiffer. [ABSTRACT FROM AUTHOR]

There have been immense research studies conducted on asphalt mixture design and the corresponding pavement performances. However, the flowability and workability of asphalt mixtures have not been well understood, which has a significant effect on the subsequent mixture performances. To quantitatively evaluate the mixing flowability of asphalt mixture and deepen the understanding of evolution mechanism of its strength composition, six types of asphalt binders were tested for their viscosities and the corresponding asphalt mixtures were prepared in this study. Their flowing behavior during the mixing process was tested at different mixing rates and temperatures using a modified Marshall mixing equipment. It was found that the higher the mixing temperature and the smaller the mixing rate, the less mixing power was consumed and the easier asphalt mixture was to mix. Moreover, the flowing behavior of asphalt mixtures can be well described by the Bingham model. Further, a new parameter termed as mixing workability index was introduced to evaluate the mixing difficulty of asphalt mixtures, and it was found that the asphalt binder types have a significant effect on mixture workability. [ABSTRACT FROM AUTHOR]

To establish the rutting prediction model of asphalt pavement under layered variable modulus, the deviation of permanent deformation prediction of asphalt pavement caused by dynamic modulus change was corrected. Based on the asphalt mixture dynamic modulus test and laboratory triaxial dynamic creep test, the correlation between the asphalt mixture dynamic modulus ( | E ∗ | ) and its high-temperature deformation resistance was verified. Abaqus finite element software was used to analyze the dynamic modulus and vertical compressive stress of asphalt pavement with depth and temperature at different times, and the correction factor (m) of vertical compressive stress of each sub layer under different dynamic modulus was proposed. According to the idea of `sub layer deformation superposition', a rutting prediction model of layered variable modulus asphalt pavement was established by using SPSS software regression analysis, which included temperature, asphalt layer thickness, vertical compressive stress, correction factor, load action times and other factors. The results showed that the established rutting prediction model can more accurately predict the permanent deformation of asphalt pavement, improve the rutting prediction accuracy of middle and lower layers by 6. 03% and 10. 34%, respectively, and improve the overall asphalt layer by 5. 19%. [ABSTRACT FROM AUTHOR]

The gussasphalt mixture has excellent water tightness, coordinated deformation ability and durability, while the epoxy asphalt mixture has extremely outstanding strength and heavy load on high temperature resistance. In order to realize the integration of the advantages of the two mixtures, the epoxy gussas-phalt mixture is proposed. The mechanical properties and 170 °C viscosity tests of epoxy resin and hot mixed epoxy asphalt from three sources were carried out; based on the mix proportion design of hot mixed epoxy gussasphalt mixture, the fluidity, Marshall, penetration, rutting, bending and fatigue performance tests of the mixture with mixing time of 45 min and 135 min were carried out. The results show that the mechanical properties of the three epoxy resins and the hot mixed epoxy asphalt are basically the same, and the viscosity is up to 1 Pa ⋅ s at 170 °C for more than 3 h; the performance of mixture attenuates greatly with the increase of mixing time; the type of epoxy asphalt has no significant effect on the performance indexes except flow value and ultimate flexural strain. When mixing for 45 min, the performance of XB epoxy gussasphalt mixture is the best, the fluidity is less than 5 s, and the constructability fluidity maintenance time is more than 135 min. The Marshall stability exceeds 48 kN, the rutting dynamic stability reaches 18 945 times/mm, the penetration increment is only 0.1 mm, and the ultimate flexural strain at - 10 °C exceeds 3 000 µε. The impact toughness of fatigue performance index reached 3 517 N ⋅ mm, and its performance was far higher than that of conventional gussasphalt mixture, and many indexes were also higher than that of epoxy asphalt mixture, and the cost is also relatively low. The hot mixed epoxy gussasphalt mixture has the advantages of both the gussasphalt mixture and the hot mixed epoxy asphalt, which can effectively improve the high-temperature strength of the gussasphalt mixture, and is of great significance to improve the quality and durability of steel bridge pavement in China. [ABSTRACT FROM AUTHOR]

In order to explore the applicability of environment -friendly polyurethane (EPU) in modified asphalt, the EPU modified asphalt was prepared by in - situ polymerization with polycarbonate diol ( PCDL ) as the soft segment and diphenylmethane diisocyanate (MDI) and butanediol (BDO) as the hard segment. FTIR test was used to analyze the chemical composition of EPU modified asphalt. The penetration, softening point, ductility, and viscosity were used to evaluate the physical properties of the modified asphalt. The compatibility of modified asphalt was evaluated by softening point difference. Dynamic shear rheological test was used to investigate the high temperature rheological properties of modified asphalt. Differential scanning calorimetry and bending rheometer experiments were used to investigate the creep mechanism of modified asphalt at low temperature. The results show that EPU molecules react with asphalt molecules in asphalt to form transaction structures. The addition of EPU can effectively improve the physical properties and high temperature properties of asphalt, and the compatibility is good. EPU has a lower glass transition temperature, so EPU also shows excellent improvement effect on the low-temperature performance of asphalt. This study can provide a new idea for the production of EPU modified asphalt. [ABSTRACT FROM AUTHOR]

To effectively utilize waste mask materials in road engineering and minimize resource waste, the melt-blown fabric (MBF) of waste masks was utilized to modify the virgin bitumen. The preparation process of MBF-modified bitumen was investigated, and the physical and rheological properties of bitumen were measured. Subsequently, the blending mechanism during preparation and the dispersion morphology of the modifier were explored. Finally, the pavement performance of the mixture was investigated, and a radar chart analysis was performed to quantitatively assess the effects of MBF modification. Results suggested that the recommended preparation process of shear time, shear rate, and shear temperature was 170 °C, 4000 r/min, and 15 min, respectively. MBF enhanced the high-temperature stability of the binder and weakened the temperature susceptibility. The modification was primarily a physical process. No network structure and agglomeration formed in the bitumen after modification. The addition of MBF significantly improved the resistance of the asphalt mixture to a high-temperature deformation and water damage but harmed its low-temperature crack resistance. The comprehensive assessment results of 0% ( f 1 ), 1% ( f 2 ), 3% ( f 3 ), and 5% ( f 4 ) MBF to improve the properties of the mixture were in the following order: f 3 > f 4 > f 2 > f 1 , where the impact of 3% MBF was the most significant, followed by 5% and 1% MBF. [ABSTRACT FROM AUTHOR]

Appropriate design in linear construction depends on many factors, including detailed geological conditions. One of the biggest problems are unrecognized erosion forms, in particular karst ones, which have a huge impact on the design and subsequent operation of roads. For this purpose, in addition to conventional methods such as drilling or geotechnical probing, which are point-based, non-invasive spatial geophysical methods are used. This article presents an example of the use of geoelectrical surveys, Electrical Resistivity Tomography (ERT) for the recognition of karst zones for linear investments. The article describes ERT investigations, which to some extent allows to identify dangerous karst phenomena occurring in the Lublin Upland (Poland), which are of great importance at the design stage of roads and in their further safe operation. Non-invasive geophysical research has been verified and confirmed by traditional geotechnical research, which confirms the effectiveness of their use. The Electrical Resistivity Tomography was used as a method providing a broader spectrum of knowledge on the spatial arrangement of soil layers in the subgrade of the planned road investments. It also enabled a more accurate, more detailed interpretation of geotechnical studies. The described geophysical investigations opens wide possibilities for their application to researchers. In the future, non-invasive methods have a chance to become as reliable as geotechnical methods, but this requires a lot of research to improve the effectiveness and accuracy of the interpretation of the obtained results. [ABSTRACT FROM AUTHOR]

"Traffication: How cars destroy nature & what we can do about it" by Donald P.F. and "A clouded leopard in the middle of the road: New thinking about roads, people, and wildlife" by D. Jones are two books that highlight the negative impacts of road networks on nature and human welfare. The books provide evidence-based analysis and practical solutions to mitigate the effects of road traffic. They emphasize the neglected topic of road ecology and its detrimental effects on biodiversity and human health. The books also discuss the ecological consequences of roadkill, the role of roads as barriers and facilitators for species movement, and the pollution generated by traffic. The authors suggest engineering solutions, legislation, and conservation-minded responses to address the issue of traffication. [Extracted from the article]

The document titled "Reviewers" expresses gratitude to the dedicated reviewers who have contributed to the success of the Journal of Cold Regions Engineering. The reviewers' timely and critical reviews are acknowledged as crucial to the journal's impact and decision-making process. The document lists the names and affiliations of the reviewers who have reviewed manuscripts submitted to the journal during a specific period. [Extracted from the article]

Asphalt pavements represent the great majority of roads worldwide. However, the bitumen physico-chemical properties change due to ageing processes during both the production and service life of the asphalt mixes. In recent years, a completely new trend has been observed in the road engineering industry oriented to extending the service life of roads, bringing direct economic, ecological and social benefits. This work presents the possibility of inhibiting ageing of road bitumen by using polyaniline nanofibers (PANI_NFs) as well as enhancing its rheological properties examined with Linear Amplitude Sweep (LAS) as well as Multiple Stress Creep and Recovery (MSCR) tests. These results show that the application of PANI_NFs maintains the primary penetration value of bitumen short-term and long-term aged road bitumen at 88 % and 52 %, respectively. Moreover, bitumen modification with PANI_NFs reduces the softening temperature increase by 33 % and 24 %, respectively, and the viscosity increase of road asphalt by 50 % and 25 %, respectively. PANI_NFs also stabilised the bitumen surface adhesion force, determined with AFM, consequently confirming the enhanced resistance to ageing processes. In addition, changes in the carbonyl index, sulphoxide index and aromaticity of bitumen demonstrated that PANI_NFs inhibit oxidation and aromatisation reactions of its components. The tests indicated a 4-fold decrease in the degree of bitumen component oxidation after short-term ageing and a 33 % decrease after long-term ageing. FTIR analysis also showed a reduction in the degree of bitumen component aromatisation process of 79 % and 76 % for short-term and long-term ageing, respectively. The LAS and MSCR test results also showed that PANI_NFs had a beneficial impact on the resistance of the bitumen to fatigue and rutting. Overall, the study results suggest that PANI_NFs consitute a promising modifier for bitumen in terms of ageing inhibition and performance characteristics. • Polyaniline nanofibers effectively inhibit the bitumen ageing process. • Polyaniline nanofibers inhibit the oxidation reactions of bitumen hydrocarbons. • Polyaniline nanofibers inhibit the aromatisation process of bitumen components. • Polyaniline nanofibers enhance the rutting and fatigue resistance of bitumen. [ABSTRACT FROM AUTHOR]

Steel slag has been investigated as a potential aggregate for pavement-wearing courses in road engineering. The volume stability, resistance to high and low temperatures, and water stability for asphalt mixtures containing steel slag have been widely studied. As for the skid resistance, previous studies have primarily focused on the initial performance. The relationship between the steel slag's appearance morphology and skid resistance during the wearing process remains to be further explored. It is essential to undertake a comparative study on the long-term skid resistance of steel slag and conventional aggregates to address the differences. This research picked two steel slags and two types of conventional aggregates (granite and limestone) as research samples. The chosen aggregate samples underwent various degrees of wear treatment with the Los Angeles abrasion machine, and their angularity was examined utilizing an aggregate image measurement system (AIMS). Based on the polishing pre-treatment, the micro-texture of the aggregates was observed with the assistance of a laser confocal microscope, and its correlation with skid resistance was determined. British pendulum number (BPN) tests were also conducted and analyzed at various polishing durations. The results show that steel slag has a low abrasion rate and higher initial angularity and abrasion resistance compared to natural stones. The micro-texture analysis demonstrates that steel slags have a coarser roughness, more contact points, and more durable abrasion resistance. Additionally, the fluctuations in BPN further prove that steel slag has superior initial and sustained skid resistance. Overall, steel slag can be a promising alternative for pavement-wearing course aggregate due to its superior long-term skid resistance. [ABSTRACT FROM AUTHOR]

Waste cooking oil (WCO) can be recycled cleanly as the rejuvenating agent for aged asphalt, boosting the utilization of reclaimed asphalt pavement materials in road engineering. However, the sensitivity of asphalt rejuvenated by WCO to secondary aging is unknown, which has an impact on its durability in practical engineering. The objective of this work is to explore the aging behaviors of asphalt binders rejuvenated by different chemical fractions of WCO. The performance of different fractions of WCO before and after aging treatment was evaluated. The sensitivity to aging was discussed for rejuvenated binders with WCO's fractions as rejuvenating agents including the differences in aging resistance between them and the virgin binder. The experimental results indicate that the aging resistance of WCO's fractions depends mainly on their carbon chain length. The sensitivity of rejuvenated asphalt to aging depends strongly on the aging resistance of WCO's fractions. Additionally, it is found that the resistance of rejuvenated binders to aging is better than that of the virgin binder because the WCO's fractions are less volatile than the original light components of the virgin binder. Therefore, substances with strong fluidity and weak volatility in WCO are the optimal candidates for rejuvenating agents of aged asphalt considering both the rejuvenation effect and the resistance to aging. The findings of the research contribute to the sustainability of road engineering. • The aging behaviors of asphalt rejuvenated by waste cooking oil (WCO) were explored. • The performance of different fractions of WCO before and after aging was evaluated. • The aging resistance of rejuvenated asphalt is better than that of the virgin binder. • The sensitivity of WCO rejuvenated asphalt to secondary aging depends strongly on the anti-aging ability of WCO's fractions. [ABSTRACT FROM AUTHOR]

In road engineering on clay foundation, the subgrade clay is often anisotropically overconsolidated, and the drainage boundary is commonly partially drained. Considering that few laboratory studies focused on the traffic-induced cyclic behaviors of anisotropically overconsolidated clay, and investigated intensively the differences in deformation between undrained and partially drained conditions, this study performs a series of one-way cyclic tests on the overconsolidated clay with various consolidation stress ratios (K) under different drainage conditions. The emphasis is put on the comparison of undrained and partially drained tests in terms of the permanent axial strain and its accumulated rate, resilient modulus and damping ratio. Test results indicate that the relative magnitude of permanent axial strain and its accumulated rate between the two drainage conditions is highly related to cycle number, K and CSR, with decreasing K and increasing CSR exacerbating the difference. The resilient modulus of partially drained tests is greater than that in undrained tests overall, while the relative relationship of degradation index between the two drainage conditions is reversed. In addition, the increase of consolidation-induced anisotropy degree promotes the strain development and improves the resilient stiffness, which should be noted for the traffic-induced deformation of subgrade clay. Based on the shakedown theory, the allowable cyclic stress ratio is determined as 0.44, and it is affected little by K or drainage condition. Finally, prediction models of permanent axial strain and resilient modulus are established for the anisotropically overconsolidated clay under both drainage conditions, where the deformation prediction is found to be related to the shakedown behavior. It is recommended that the prediction and control of subgrade clay settlement in engineering practice should take into account the in-situ consolidation sate and drainage condition. • Drainage condition has great and complex influences on cyclic behaviors of anisotropically overconsolidated clay. • The increase of consolidation anisotropy aggravates deformation difference between two drainage conditions. • The increase of consolidation anisotropy increases permanent strain and resilient stiffness, decreases damping ratio. • The allowable cyclic stress ratio is affected little by consolidation anisotropy or drainage condition. • Prediction models of permanent strain and resilient modulus are established. [ABSTRACT FROM AUTHOR]

Creation of road and railway routes in general and also design of vertical alignment in particular constitute an significant engineering problem. The vertical alignment of roads, and especially of railways, is of great importance for passenger comfort under high-speed driving conditions. This requires alignment smoothness to a greater extent. In practice, the dominant tendency is to consider vertical arcs as parabolic curves (quadratic or cubic). Other solutions have been also proposed and analyzed in the literature, thus providing an alternative approach to traditional methods. This paper describes a design method of vertical arcs using the so-called general transition curves. These curves describe the entire curvilinear transition between two straight lines using a single equation, and the curvature at the contact points with the straight lines is zero, which is of great practical significance in the light of vehicle motion dynamics. As a result, relevant research shows that general transition curves, compared to other curves, provide a more favorable distribution of lateral changes of acceleration. The paper deals not only with appropriate design procedures of a general nature, but also specific procedures of fitting vertical arcs to preset points. The methods for designing vertical arcs constitute a useful extension of available methods, and offer a valuable tool for engineers and designers of road and railway routes. • a new approach to the design of vertical arcs was presented • the proposed approach is based on the use of so-called general transition curves • these curves are the original design tool and describe the entire transition between two straight lines with one equation • the proposed approach is algorithmic and can be very useful in computer-aided design [ABSTRACT FROM AUTHOR]

Nickel–iron slag, a byproduct of industrial processes in China with an annual production exceeding 400,000 tons, is considered an industrial waste material. This study focuses on the rational utilization of nickel–iron slag by investigating its mechanical properties and road performance as a roadbed fill material. Initially, a detailed analysis of the grading curve of pure nickel–iron slag was conducted, leading to the proposal of various modification schemes for nickel–iron slag. Subsequently, static triaxial tests were performed on nickel–iron slag-clay mixtures to explore the impact of different factors on the stress–strain curve of nickel–iron slag-modified soil. Utilizing these discoveries, a formula for the molar Coulomb shear strength of nickel–iron slag-modified soil was derived. In addition, a numerical simulation study of a nickel–iron slag-reinforced embankment was conducted, integrating field tests. This aimed to investigate the variations in the compression layer sedimentation-thickness ratio and settlement factor of nickel–iron slag-modified soil reinforced embankment under different filling heights and slope rates. The results informed the development of a prediction model for the settlement ratio of nickel–iron slag-modified soil-reinforced embankment. Key findings indicate that pure nickel–iron slag exhibits poorly graded gravel sand characteristics, and optimal gradation is achieved when clay doping ranges from 30% to 40%. As the clay content increases, the stress–strain curve of nickel–iron slag-clay transitions from strain-hardening to strain-softening. Furthermore, the stress–strain curve of nickel–iron slag-cement-clay exhibits strain-softening, and the shear strength fitting formula demonstrates high computational accuracy with a small error range. Numerical simulations reveal that the sink-thickness ratio and settlement factor are minimally affected by the slope rate. The sink-thickness ratio increases with the elevation of filling height, while the settlement factor fluctuates within a small range. The proposed sink-thickness ratio prediction model exhibits high accuracy and strong generalization capabilities. This comprehensive study provides valuable insights into the efficient utilization of nickel–iron slag in construction and road engineering. • Nickel–iron slag, a major industrial waste in China, can be efficiently repurposed for roadbed fill material. • Optimal gradation is achieved with 30%–40% clay doping, impacting the stress–strain curve of nickel–iron slag. • Study unveils formula for molar Coulomb strength of nickel–iron slag. • Numerical simulations reveal minimal impact of slope rate on sink-thickness ratio in reinforced embankments. • Accurate prediction model for settlement in nickel–iron slag-modified soil. [ABSTRACT FROM AUTHOR]

The huge amount of red mud has brought great challenges to the sustainability of global economic development. Red mud, a solid waste, causes resource wastage and environmental pollution, even endangering human health. A technology used to overcome such a situation involves broad-scale recycling of red mud in road engineering. In this study, Bayer red mud is utilized as a high-performance grouting material for semi-flexible pavement (SFP). A series of sensitivity analyses are performed using macroscale testing to determine the optimal amount of red mud and water-cement ratio for red mud-based cementitious materials (RCM) grouting material. This includes alkali-activated "red mud-slag powder" binary cementitious material (RSCM) and non-alkali-activated "red mud-cement" cementitious material (RCCM). Additionally, the hydration process and products of RCM are analyzed using microscale testing, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The results of the analysis indicate that red mud has significant potential for recycling as SFP materials to achieve the goal of high fluidity and early strength. The workability and early strength of RCCM are even higher than those of cement, indicating that part of the cement can be replaced by red mud. Moreover, the macroscale conclusions of RCM can be confirmed by microscale testing. These low-carbon grouting materials offer the added advantages of recycling waste that would otherwise be destined for landfill, along with reducing the carbon footprint and economic impact associated with cement production. [ABSTRACT FROM AUTHOR]

Accurately monitoring micro-level strain within pavements poses a significant challenge in contemporary road engineering, limiting the effectiveness of early-stage pavement health diagnostics. Addressing this critical gap, this study introduces an innovative ultra-low detection limit sensor, specifically designed for intricate pavement health monitoring. It pivots on the unique structural design of a well-ordered 3D conductive network, where the self-assembly effect of microsphere arrays ingeniously mitigates the prevalent issue of nanofiller agglomeration within polymer matrices. The study highlights the significant role of carbon nanotubes (CNTs) length in shaping the structure of conductive networks, revealing that while longer CNTs lead to less uniform microsphere assemblies, they significantly enhance the bridging effect crucial for conductive pathways. To balance these traits, surface chemical modifications were strategically applied, effectively enhancing microsphere organization and dispersion, thereby elevating the conductive and sensing performance. The optimized sensor stands out for the ultra-low detection limit of 0.0005% (5 uε), significantly surpassing those of current strain sensors. Moreover, it exhibits remarkable sensitivity, evidenced by a gauge factor of 13.2, along with swift response and recovery times of 19 ms and 26 ms respectively, and impressive durability, enduring over 100,000 loading-unloading cycles. Field tests under diverse vehicular loads and speeds further validate the sensor's accuracy in capturing dynamic responses within pavement structures, a key factor in proactive pavement maintenance and management. Hence, this advancement shows promise in contributing to the development of safer and more resilient road networks, playing a beneficial role in the significant progress of intelligent transportation and sustainable infrastructure management. • An ultra-low detection limit sensor was developed for pavement health monitoring. • Self-assembled conductive microsphere array was proposed to enhance performance. • Surface chemical modification was strategically applied to enhance the conductive network. • New sensor significantly outperforms traditional methods in detecting micro-level strain. • Demonstrated effectiveness in real-world tests under varying vehicular loads and speeds. [ABSTRACT FROM AUTHOR]

The application of machine learning techniques in pavement health monitoring based on computer vision has greatly improved the accuracy and efficiency in the detection of pavement distress levels and categories. However, a persistent challenge in this field is the issue of sample imbalance, primarily arising from the scarcity of cracked pavement images, which hampers their effectiveness in road maintenance engineering. To address this issue and enhance the fast and stable generation of high-quality crack images for engineering purposes, this study proposes two frameworks based on Generative Adversarial Networks (GAN): Multi-Stage GAN-v1 and Multi-Stage GAN-v2. These frameworks break down the complex task of directly generating high-quality images into a series of incremental steps, gradually increasing the image resolution from initially generated low-precision images. Both versions, v1 and v2, consist of multiple sequentially connected generation units, with each unit utilizing the Wasserstein Generative Adversarial Network-Gradient Penalty (WGAN-GP). Furthermore, v2 has the additional capability of generating pavement crack images of specified types and simultaneously providing crack segmentation labels. This feature significantly enhances the practical applicability of the generated data in engineering contexts. In a comprehensive case study, the evaluation results clearly illustrate the superior image generation quality from the two proposed frameworks. Moreover, the results from ablation experiments, involving the training of nine state-of-the-art crack semantic segmentation and object detection networks using both generated images and real images, demonstrate the effective utility of these generated images for training pavement distress detection networks. [ABSTRACT FROM AUTHOR]

Permafrost in the Qinghai-Tibet Plateau (QTP) accounts for a total area of 1.05 × 106 km2. Many highway engineerings have been through the permafrost regions of the QTP, including the Qingkang Highway (QKH), Qinghai-Tibet Highway (QTH), and Gonghe-Yushu expressway (GYE), and the Qinghai-Tibet expressway (QTE) will be constructed in the future. Under the action of roadbed construction and global warming, permafrost under roadbed is degraded and causes serious pavement damage. Although many useful cooling measures have been applied to prevent permafrost degradation, their application presents significant challenges on account of the stronger endothermic action of asphalt pavement. This paper summarizes the working principle of existing cooling measures, and ascertains the relationship between pavement damage and ground temperature distribution of permafrost under roadbed. Based on the relationship, geotemperature distribution criteria and requirements for the cooling measures are proposed, and some suitable composite structures and measures are suggested. The results reported in this paper can provide a valuable guidance for the design and construction of the QTE in the future. • Relationship between temperature distribution and damage characteristics is revealed. • Geotemperature distribution criteria for the cooling measures are established. • Some composite measures are proposed for roadbed in permafrost regions of the QTP. [ABSTRACT FROM AUTHOR]

The study of microscopic processes in modified asphalt is crucial for road engineering but has been challenged by difficulties and means limitations. The phase field model, on the other hand, can accurately simulate and track the evolution of the microscopic phase state of modified asphalt with respect to time, and by simulating the interactions and distribution of different asphalt components, we can predict the asphalt microscopic processes under different conditions. This paper reviews the application of phase field theory to microscopic phase separation, self-healing and fracture behavior of asphalt, and concludes with a brief summary and outlook on the current problems in the application of phase field theory to modified asphalt. • The phase field theory can accurately model and track the evolution of the microscopic phase state of modified bitumen over time, providing insight into the phase separation process. • Allen-Cahn kinetics and Navier-Stokes equations coupled with evolving phase field variables are used to simulate the self-healing process of asphalt. • The interactions and distribution of different components of asphalt are modeled by phase field theory to predict the fracture properties of asphalt under different conditions. [ABSTRACT FROM AUTHOR]

Volatile organic compound (VOC) emissions are becoming an increasingly significant issue because of the increasing demand for bitumen in road engineering. This study attempted to develop a type of fume-suppressed bitumen with good comprehensive performance. Initially, 1, 2, and 3% organic montmorillonite and 2, 3, and 4% waxy warm-mix agents were utilised to modify bitumen. Subsequently, the fume suppression and physical and construction performances of the modified bitumen were evaluated, and the modified bitumen with the best comprehensive performance was determined. On this basis, constant- and variable-temperature heating modes were designed to verify the fuel suppression performance of the modified bitumen thoroughly. Finally, the modification mechanism of modified bitumen was investigated via atomic force microscopy. The results indicate that the modifier had the greatest impact on the ductility of the modified bitumen in terms of its physical performance. Although waxy warm mixed agents increase VOC emissions, organic montmorillonite can inhibit this effect. The modified bitumen, composed of 2% organic montmorillonite and 2% waxy warm mix agent, has the best comprehensive performance, with a 40.6% emission reduction rate under constant temperature heating mode and 46.4–28% range from 200 ℃ to 120 ℃ under another mode. The waxy warm mix agents and organic montmorillonite-modified bitumen developed into continuous and dispersed phase systems, respectively, leading to variations in the modified bitumen's physical performance and VOC emission capacity. In contrast, the composite-modified bitumen exhibited a two-phase structure with the surface morphology of an 'egg tray'. This unique structure enhances the heating surface area and facilitates heat conduction, improving the bitumen performance during construction. [Display omitted] • Consideration was given to the VOC emission reduction effect caused by the decrease in viscosity of bitumen. • The efficacy of fume suppression asphalt was verified in two heating modes. • A fume suppression asphalt with commendable comprehensive performance was designed. [ABSTRACT FROM AUTHOR]

Waste sludge is a typical solid waste generated during construction excavation, which needs innocuity treatment and resource utilization. The development of geopolymer pavement base material using waste sludge is an economic and environmental method to realize the utilization of waste sludge. This manuscript aims to develop a geopolymer pavement base material using waste sludge and further evaluate its water stability under water soaking environment. The geopolymer specimens with different slag and waste sludge contents were prepared. The optimum mix proportion of geopolymer was determined by analyzing the effect of slag content on the ultimate compressive strength (UCS) and elastic modulus. The CO 2 emissions and energy consumption of geopolymer was analyzed. The water stability of the geopolymer was further evaluated by analyzing the effects of soaking time on the density, wave velocity, mechanical properties and pore structure. The results show that the geopolymer with 50% slag content has the largest UCS and excellent strength development characteristics. The UCS of geopolymer pavement base material reaches 48.4 MPa and the CO 2 emissions and energy consumption were reduced by 58.34% and 88.16% compared to C40 ordinary concrete. The results also show that the density, longitudinal wave velocity and porosity remain stable as soaking time increases. During the soaking process, the proportion of gel pores and transition pores decreases, while the proportion of capillary pores and air pores increases. The UCS of geopolymer pavement base material remains above 40 MPa after soaking for 90 days, showing excellent water stability. The geopolymer pavement base material has the potential application prospect in road engineering and emission reduction, which provides a feasible and cost-effective method for the utilization of waste sludge. • The geopolymer pavement base material were developed using water sludge. • The optimal mix proportion of geopolymer prepared by water sludge was proposed. • The geopolymer prepared by water sludge has excellent strength development. • The geopolymer maintains high integrity and mechanical properties after soaking. [ABSTRACT FROM AUTHOR]

Solar pavement can convert sunlight shining on the pavement surface into clean electricity through photovoltaic panels, thereby transforming the energy structure of road transportation. In order to balance the light transmittance and anti-skid resistance of the solar pavement surface, this study proposed a concentrated photovoltaic panel (CPP) structure for pavement. The panel structure was optimized, and a laboratory model was developed. The mechanical properties and durability of the panel were tested by the multi-functional material test system (MTS) and the model mobile load simulator 3 (MMLS3). Furthermore, the electrical performance was evaluated by an outdoor test, followed by an economic evaluation. The results show that the optimal structural dimensions of the CPP for pavement are 540 mm long × 540 mm in length × 144.62 mm in thickness. The maximum flexural tensile strength of its anti-skid concentrated panel is 61.67 MPa, satisfying the requirements of the traffic load. After 1.35 million cycles of loading, the surface of the anti-skid concentrated panel is free of cracks and deformation and has no obvious wear, exhibiting good transmittance durability and excellent wear resistance. In addition, the overall structure of the panel counteracts the light loss effect of the material and improves the light concentration performance, providing a gain effect on the power generation of the panel, especially in the case of high irradiance. The return on investment (ROI) of CPP for pavement is 54.42%, with cost recovery in 9.87 years. The levelized cost of energy is 0.67 CNY/kWh, indicating significant economic benefits. At the same time, 1539.3 kg/m2 of CO 2 emissions can be avoided during the operation cycle, and the environmental benefits are also considerable. This study can provide a reference for the promotion and application of photovoltaic power generation technology in road engineering. • The structure design scheme of concentrated photovoltaic panels for pavement is proposed. • The optimal dimensions of CPSP for traffic loading are determined. • The mechanical performance, transmittance durability, and power generation performance of CPPs are tested and evaluated. • The levelized cost of electricity generated from CPP is 0.67 CNY/kWh. [ABSTRACT FROM AUTHOR]

It has been proved that nanosilica can improve the mechanical properties of cement soil, however, the static and dynamic properties of nanosilica modified cement soil and dispersion method study of nanosilica in cement soil were few, thereby investigated by unconfined compression test and dynamic triaxial test in this study. A series of unconfined compression test results indicated that the dispersion method of nanosilica is of importance in the strength of nanosilica modified cement soil (NCS), and soaking in water for 24 h is the optimal dispersion method among designed methods. Unconfined compressive strength (UCS) increases with increasing nanosilica content in the range of 0 to 0.4%, and then reduces gradually while nanosilica content is beyond 0.4%. The optimal nanosilica content can be seen as 0.4%, and the corresponding UCS at the curing age of 7 d is 960 kPa, which increases by 47.2% comparing to the specimen without nanosilica. Dynamic triaxial test reveals that the variation of the cumulative plastic axial strain and dynamic elastic modulus versus nanosilica content are same and opposite to UCS respectively, and the minimum of the cumulative plastic axial strain and maximum of dynamic elastic modulus are obtained while nanosilica content is 0.4%, which reduces by 48.1% and increases by 69.8% respectively comparing to the specimen without nanosilica. Finally, a simple and practical prediction model is developed to capture the evolution of the cumulative plastic axial strain with cycle number, and its simulation effect is validated by dynamic triaxial test results. It is believed that this paper finds an efficient dispersion method of nanosilica in cement soil, and provides the dynamic properties of nanosilica modified cement soil, which can promote practical application of nanosilica in road engineering. [Display omitted] • Soaking in water for 24 h can efficiently increase the dispersion extent of nanosilica in cement soil. • 0.4% is the optimal content of nanosilica to modify cement soil, which can achieve the best strength improvement. • The proposed model has the satisfactory capability to simulate the cumulative strain behavior under cycle load. [ABSTRACT FROM AUTHOR]

In the seasonal frozen regions, the bridge expansion joint concrete (BEJC) is susceptible to damage during its service life, not only from vehicular loads but also from chloride salt erosion and the effects of freeze-thaw cycles. This study investigates the basic physical and mechanical properties of BEJC under different curing conditions. A rapid chloride permeability test was conducted to comparatively analyze the concrete's chloride ion penetration resistance. The microscopic crack width on the concrete bond surface is evaluated to assess the concrete bond performance under different loading durations. Additionally, the study explores the coupled effect of wheel loads and single-sided salt freeze-thaw cycles (WL-SFT) on the freeze-thaw resistance of BEJC, delving into factors such as spalling mass, water absorption rate, and pore structure characteristics (including air content, specific surface area, spacing coefficient) and connectivity. The results indicate that for specimens subjected to loading at 1–14 days and 3–14 days, the average crack widths on the bond surface are 14.36 µm and 10.09 µm, respectively, representing 5.27 times and 3.70 times those of unloaded specimens. The bond strength also decreases by 34.8% and 14.2%, respectively, compared to unloaded specimens. The increase in crack width leads to a reduction in bond strength, highlighting the importance of bond strength as a consideration for the actual opening time of roads in engineering projects. Furthermore, due to its smaller and more stable pore structure, the study suggests that WL-SFT almost does not damage standard curing (SC) concrete; however, it slightly disrupts the pore structure of natural curing (NC) concrete. In comparison, WL-SFT leads to the generation of more microcracks in both the surface and deeper layers of low-temperature curing (LC) concrete, resulting in the destruction of its pore structure and connectivity. • The changes in crack at the bonding surface after the application of wheel loads were investigated at the microscopic level. • The study investigated the combined impact of wheel loads and single-sided salt freeze-thaw cycles. • The surface pore structure and connectivity of the concrete were analyzed. • The extent of concrete damage was quantified by measuring the free chloride ion content at different depths of concrete. [ABSTRACT FROM AUTHOR]

To address issues related to the limited improvement in the performance of phase-change material (PCMs) modified asphalt and the unclear underlying mechanisms, this study developed two structurally stable and thermally efficient coal gangue composite phase-change agents. The impact on enhancing the properties of asphalt was systematically investigated. The study revealed that when the dosage of the phase-change agent is below 20%, there was a pronounced interactive effect between the agent and asphalt. This interaction had the capability to regulate both the non-polar and polar components within the asphalt colloid system. By controlling the dosage of the PCMs agent, it was possible to enhance the high-temperature rheological properties, high-temperature shear resistance and low-temperature flexibility of the asphalt. Additionally, this control improved the adhesion and moisture sensitivity of the PCMs modified asphalt and aggregate system. The maximum temperature-regulating effect of PCMs modified asphalt could reach up to 8.3 °C, with the functional attribute strongly correlated with the low-temperature performance of the asphalt. This research contributes to the promotion and application of PCMs in road engineering. • The service performance of asphalt can be improved by adding CPER or APER. • The adhesion between phase change asphalt and mineral aggregates was enhanced. • CPER or APER can endow asphalt with the temperature regulation ability. [ABSTRACT FROM AUTHOR]

Bitumen, a vital component in asphalt mixtures for road construction, confronts persistent challenges stemming from traffic loads and temperature fluctuations, leading to issues such as permanent deformation, fatigue, and thermal cracking, ultimately jeopardizing road safety. A promising solution involves enhancing asphalt mixture performance through asphalt binder modifiers, including biopolymer materials. Among these, non-petroleum-based biodegradable polymers, such as natural rubber and natural oil, stand out as viable options in highway engineering. This comprehensive review commences by introducing various biopolymeric materials, delving into their types, sources, and processing methods. Their interaction mechanism with bitumen is also discussed. Subsequently, it summarizes the production of bio-advantaged polymer-modified bitumens and mixtures. The study meticulously analyzes the rheological and chemo-mechanical properties of biopolymer-modified bitumens and underscores their mixture performances. Finally, the economic and environmental sustainability of the biopolymer-based bitumens was also evaluated. Natural rubbers enhance rutting, fatigue, thermal cracking, aging resistance, and moisture resistance in bitumen or mixtures, but do increase viscosity, which reduces workability. Natural oils improve fatigue, thermal cracking, and aging resistance without impacting rutting or moisture susceptibility in bitumen or mixtures. Biopolymer-modified asphalt presents the potential to reduce annual maintenance expenses while promoting sustainable road construction. To satisfy road pavement applications, cup lump rubber and extraction oil can be utilized. To further advance this field, future research should focus on utilizing more advanced biopolymers through innovative optimization and interaction mechanisms with other modifiers (e.g., epoxidation and polymerization) to render asphalt mixtures both economical and environmentally friendly without compromising their performance. [ABSTRACT FROM AUTHOR]

• A two-dimensional piezoelectric transducer is developed. • The piezoelectric equation under cyclic loading is derived and verified. • Piezoelectric equation is applicable to piezoelectric transducer installed in UGMs. • Piezoelectric transducer is potential to monitor dynamic soil stresses. In road engineering, the applications of piezoelectric ceramics on road energy harvesting or electronic sensing have drawn many attentions. However, the application potential of piezoelectric sensor on UGMs (unbound granular materials) in road is unclear. The main problem is the applicability of piezoelectric equation considering that the soil structure of UGMs and the working environment that the transducer may suffer may influence the transferred stress on the piezoelectric transducer and then the electricity generation. In this study, a two-dimensional piezoelectric transducer made by PZT-5H piezoelectric ceramics was installed in the sample of UGMs, and a series of cyclic tests were performed on the UGMs samples by a large-scale triaxial apparatus. This test method is specially designed for the case that the piezoelectric transducer is installed in UGMs of pavement base/subbase layers and then undergo traffic loading under complex working environment. Test results show that the electricity generation is primarily dependent on the magnitude and frequency of cyclic loading, while the influences of other factors are limited. The piezoelectric equation to calculate the open-circuit voltage is deduced and verified under the complex working environment. This indicates that the piezoelectric equation is applicable to the case that the applied stress on the piezoelectric transducer is transferred from the soil medium, and the two-dimensional piezoelectric transducer has a sensor potential to monitor the dynamic vertical and horizontal soil stresses under traffic loading. [ABSTRACT FROM AUTHOR]

To reduce the high-temperature distress of asphalt pavement and alleviate the urban heat island effect, one-component polyurea composite phase change cooling coating was prepared. Through the tests of storage time, curing time, hardness and tensile property, the performance variation of one-component polyurea under different latent curing agent dosage were analyzed. Through the tests of road performance and thermoregulation performance, the change rule of road performance and cooling effect of one-component polyurea composite phase change cooling coating under different amount of phase change particle admixture and coating were analyzed. The results showed that the phase-change cooling coating prepared in this study can meet the requirements of road performance. When the dosage of phase change particles is 20% and the amount of coating is 1.2 kg/m2, the maximum cooling effect of the coating reached 3.7 °C under the simulated indoor conditions and 3.3 °C under the real outdoor environment. [ABSTRACT FROM AUTHOR]