Transport Research International Documentation (TRID)

Stiffness and Cracking Resistance Evaluation of Cold Bitumen Emulsion Mixtures Incorporated with Waste Glass Aggregates

Tue, 28 Apr 2026 16:55:33 GMT

Continuous use of hot mix asphalt (HMA) accelerates environmental deterioration, fossil fuel consumption, global warming, and depletion of natural resources. Further, waste generation and its disposal problem are also a threat to environment. The production of waste and the use of energy/virgin materials in HMA construction must be addressed concurrently. A right step toward the creation of environment-friendly road infrastructure is the use of Cold Bitumen Emulsion Mixtures (CBEMs), a form of Cold Mix Asphalt (CMA). Cold mix asphalt may be made more environment friendly by using waste materials as fine aggregates. In this study, Waste Glass (WG) is substituted for virgin fine aggregate at various percentages ranging from 0 to 100% (with 20% increments) in the binder layer of the CBEM. As per Marshall stability, Marshall flow, indirect tensile strength (ITS), and resilient modulus, the mechanical performance of CBEM-WG mixtures is assessed in this work. The performance of various CBEM-WG mixes is compared with each other, normal CBEM (NCBEM) and also with HMA. According to the findings, mechanical performance of CBEM having WG contents up to 60% was equivalent to that of normal CBEM (NCBEM) and conventional HMA, and it demonstrated superior performance at 60% plus WG content levels. The statistical analysis was performed to prove the feasibility and validity of replacing virgin materials with waste glass in terms of mechanical properties. The coefficient of determination R² > 0.9 for all properties indicated addition of waste glass has significant impact on mechanical performance.

Mechanical Performance and Life Cycle Assessment of Semiflexible Pavement Using Sustainable Grout

Tue, 14 Apr 2026 14:32:30 GMT

The efficient utilization of construction waste in road engineering is essential for advancing sustainable infrastructure development. This study explores the application of ceramic waste powder (CWP) in cementitious grout for semiflexible pavement (SFP) surfaces. Cement was partially replaced with CWP at proportions ranging from 15% to 50%, and its effects on SFP performance and environmental impact were evaluated using compressive strength testing, life cycle assessment (LCA), and statistical analysis. The obtained SFP mixtures were assessed for volumetric and mechanical properties through Marshall stability and wheel tracking tests. Experimental findings revealed that 20% cement replacement with CWP was the optimal level, leading to an 80% reduction in rutting depth and increases of 50% and 23% in compressive strength and Marshall stability, respectively, at 28 days of curing. These improvements are attributed to CWP’s superior fluidity in filling the voids within the porous asphalt skeleton and its effective bonding capacity with aggregates, which densifies the microstructure, as confirmed by scanning electron microscopy (SEM) analysis. LCA results indicated that higher CWP replacement levels reduced both global warming potential and fossil fuel depletion, thereby enhancing the grout’s sustainability. Statistical analyses, including quadratic regression, ANOVA (p<0.05), and the Tukey HSD test, confirmed significant improvements in strength properties with CWP incorporation, whereas box plots effectively illustrated data trends and variations. In summary, this study underscores the dual environmental and performance benefits of incorporating CWP in SFP systems and supports its adoption in sustainable road construction aligned with circular economy goals.

Physical Parameters Estimation Using Roadside Monocular Vision

Fri, 03 Apr 2026 12:13:34 GMT

Roadside sensing is an important part of intelligent traffic management systems (ITMSs) for collecting and processing information. In order to better assess and maintain the stability and safety of objects in traffic scenes, all types of basic information are required. This paper proposes a monocular vision-based object parameter measurement and geolocation method to address the problems of high cost and limited information dimension of traditional roadside sensors. Object detection and geometric transformation mapping are combined to achieve efficient estimation of key physical parameters with input of monocular images, and global navigation satellite system (GNSS) information is further incorporated to obtain geolocation of the target. In the method, after the key target is recognized by the neural network-based object detection algorithm, the pixel-level 2D image information is mapped to a series of 3D spaces based on the construction of a geometric model, which leads to further computation of various physical parameters, realizing multi-parameter estimation under one method. The method overcomes the dependence on fixed environments or known references and is highly applicable to non-cooperative scenes. The effectiveness of the method is shown via the experiments in multiple real scenes.

Utilizing renewable resources: Enhanced high- and low-temperature properties of asphalt modified with acetylated sodium lignosulfonate and pine needle oil

Mon, 30 Mar 2026 17:10:42 GMT

Nowadays, many asphalt modifiers struggle to achieve an optimal balance between performance at both high and low temperatures. This study developed a novel composite modifier combining acetylated sodium lignosulfonate and pine needle oil aiming to address this issue and verify its performance enhancement effect on base asphalt. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscopy (ESEM), water contact angle(WCA), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) were used to investigate the thermal stability, chemical properties, compatibility, rheological performance of acetylated sodium lignosulfonate/pine needle oil-modified asphalt, while revealing the synergistic modification mechanism. The optimal modification parameters were determined as 8 % acetylated sodium lignosulfonate, 2 % pine needle oil, and a blending temperature of 150 ℃. The incorporation of acetylated sodium lignosulfonate significantly improved the high-temperature rutting resistance of the base asphalt, while pine needle oil effectively counteracted the negative impact of acetylated sodium lignosulfonate on low temperature cracking resistance. Furthermore, acetylation was found to enhance the thermal stability of sodium lignosulfonate, and the synergistic use of acetylated sodium lignosulfonate and pine needle oil improved the compatibility between the modifier and the asphalt binder. This research offers an innovative and eco-friendly approach to transform industrial lignin waste into sustainable pavement materials, contributing to cleaner production and resource efficiency in road construction.

Sustained-Thermal-Regulation Composite PCMs Using Porous Waste-Derived Support and Epoxy Encapsulation for Enhanced Thermal Resilience of Asphalt Pavements

Wed, 25 Mar 2026 11:46:31 GMT

Polyethylene glycol (PEG) has been widely recognized as a promising phase-change heat storage material for enhancing the high-temperature adaptability of asphalt pavements. However, PEG tends to leak during melting, which compromises pavement performance and long-term functionality. To address this issue, a dual strategy combining vacuum impregnation and epoxy encapsulation was developed to prepare composite phase-change materials (cPCMs) with high latent heat and anti-leakage properties. PEG was first adsorbed into porous carriers via vacuum impregnation and subsequently encapsulated with epoxy resin. Various carrier-supported cPCMs were incorporated into asphalt for comparative evaluation. The composites were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and leakage tests, while the modified asphalts were evaluated by DSC, conventional tests, dynamic shear rheometer (DSR), and bending beam rheometer (BBR). Results showed that epoxy encapsulation significantly enhanced integrity and durability. Among all carriers, red-mud-based cPCM exhibited the highest latent heat of 135.54J/g, zero leakage after 100 thermal cycles, and superior thermal stability with only 0.11% mass loss at 250 °C. The corresponding phase-change asphalt demonstrated excellent temperature-regulating capability and met pavement performance requirements under both high- and low-temperature conditions. Overall, this dual strategy effectively realizes long-term thermal regulation for asphalt pavements and promotes the sustainable reuse of solid waste materials such as red mud, offering a green and durable solution for smart, energy-responsive road systems.

Porosity–Grouting–Luminescence Coupling Mechanism and Durability of Semi-Flexible Self-Luminous Pavements

Tue, 24 Mar 2026 16:23:00 GMT

The development of self-luminous pavements offers a promising strategy to enhance nighttime road visibility and reduce external lighting energy consumption. This study proposes a semi-flexible self-luminous (SFSL) pavement by filling the interconnected voids of porous asphalt with a cement-based luminescent grouting system containing long afterglow phosphors (SrAl₂O₄: Eu²⁺, Dy³⁺). A comprehensive evaluation was conducted to correlate porosities, grout setting time, and filling efficiency with the luminescent area and optical performance. High-precision image recognition based on OpenCV algorithms was introduced for quantitative analysis of luminous coverage, enabling accurate assessment of luminescence uniformity. The results indicate that porosities of 20–22% and a grout setting time within 25min achieve optimal light-emitting efficiency and penetration depth (~20mm). A strong linear correlation (R² > 0.93) was found between the connected voids and the luminous area. Mechanical and durability evaluations revealed that SFSL pavements maintain excellent rutting resistance, skid resistance, and water stability, while a moderate reduction in low-temperature flexibility was observed. Outdoor illumination tests demonstrated persistent luminescence exceeding 6h under natural solar excitation, even in cloudy conditions. Accelerated loading tests identified a three-phase degradation pattern—rapid, stable, and slow decay—characterizing the attenuation of both optical and skid resistance performance. This research establishes the mechanism of porosity–grouting–luminescence coupling in semi-flexible systems and provides quantitative design guidance for balancing structural strength, durability, and energy-saving functionality. The proposed SFSL pavement system demonstrates substantial potential for sustainable and self-illuminated roadway applications.

Performance grading and mechanistic design method of base course incorporating RCP and RCA stabilized with asphalt

Fri, 20 Mar 2026 08:41:00 GMT

With the rapid growth of construction and demolition waste (C&DW), its resource utilization has become an important research direction in road engineering. Although the application potential of recycled concrete aggregate (RCA) and recycled concrete powder (RCP) in road base courses has gained attention, the synergistic use of RCA and RCP in asphalt-stabilized base courses still lacks systematic performance evaluation methods and corresponding design theory. Furthermore, the absence of a scientific classification system tailored to different road grades results in insufficient guidance for material selection in engineering practice. To address these issues, this study first established a three-tier classification system for recycled mixtures based on performance grade (PG) through multi-scale testing and principal component analysis. Subsequently, leveraging KENLAYER mechanical simulations, a corresponding performance-graded mechanistic design (PGMD) method was proposed. Results indicate that RCP as a filler significantly enhances the high-temperature performance and deformation resistance of the mastic. The RCP75 mastic demonstrated lower temperature and frequency sensitivity, along with a broader applicable temperature range. The RCA60 mixture exhibited optimal performance in high-temperature stability and moisture stability, with improvements of 91.8 % and 6.9 % respectively, achieving a PG value of 0.878 and a Grade I rating, meeting the technical requirements for high-grade highway base courses. Based on these findings, a thickness design equation and nomogram for the base course were developed using PG and the number of axle load repetitions (Ne) as variables, balancing structural reliability and material economy. This study provides theoretical support and design methods for the standardized and high-value application of construction solid waste in high-standard road base courses.

Performance evaluation of polymer latex-modified asphalt emulsion and cold recycling mixture

Fri, 20 Mar 2026 08:41:00 GMT

Emulsified asphalt cold recycled mixture is an effective type of energy-saving and environmentally friendly road-building material. However, the base emulsified asphalt exhibits limited performance. Thus, polymer latexes, including Styrene-Butadiene-Styrene block copolymer (SBS), Styrene-Butadiene Rubber (SBR), and their hybrid systems, have emerged as effective modifiers to enhance the performance of emulsified asphalt. This study provides a thorough comparison of SBS latex-modified, SBR latex-modified, and SBS/SBR hybrid latex-modified emulsified asphalts, evaluating their rheological properties, adhesion characteristics, and pavement performance of asphalt mixtures, including fatigue resistance. Three latex-modified emulsified asphalts were prepared using the post-emulsification modification process. Dynamic Shear Rheometer (DSR) analysis showed SBS-modified emulsions had a 300 % higher complex shear modulus at 60 °C than the base emulsion. Bending Beam Rheometer (BBR) tests indicated SBR-modified emulsions had a 20 % lower complex modulus at − 24 °C. Boiling water adhesion tests revealed hybrid-modified emulsions had a 55 % lower gray scale value than single latex modifications. The radar chart evaluation system not only resolved the conflict between different test results for the same performance of the mixture but also enabled a quantitative analysis of comprehensive performance. Through this analysis, the SBR latex-modified asphalt mixture was identified as having the best overall performance. The findings were applied to lower course of the cold recycling test road, with core sampling tests verifying their stability and applicability in real service conditions. This work delivers a selection strategy for polymer latex-modified emulsified asphalts, offering tailored solutions for diverse pavement service environments.

Rapid Bridge Replacement of Concrete Rigid Frame Bridges

Thu, 12 Mar 2026 08:52:52 GMT

A rapid bridge replacement (RBR) method was designed and utilized for the replacement of five overpasses along Highway 417 at Rochester Street, Booth Street, Percy Street, Preston Street, and Bronson Avenue in Ottawa. The current paper focuses on the replacement of the overpass at Bronson Avenue which involved the replacement of two rigid frame structures, supporting eastbound and westbound lanes (EBL and WBL), separated by a 20 mm expansion joint gap. The existing concrete rigid frame structures were demolished in place while preserving the existing footings, with excavation being performed in parallel. The new structures were prefabricated in staging areas near the sites and transported to their final locations using specialized heavy-lift equipment, including self-propelled modular transporters (SPMTs). The new rigid frames were founded on top of the existing footings. Several replacement alternatives were studied, including staged construction, rapid bridge replacement with a composite steel girder deck, and the construction of a secant wall behind the footings during nightly closures. It was concluded that the engineering and construction costs for a rigid frame RBR alternative is the lowest cost among feasible alternatives and had the least impact on traffic. A three-dimensional, linear elastic finite element analysis was conducted to ensure the strength and stability of the structures during lifting, transportation, and final backfilled service conditions. This presentation discusses the challenges encountered during the design and construction of the structure and the solutions implemented to address them. The construction was successfully completed in July 2023.

Multi-criteria assessment of recycled polyethylene terephthalate (PET) incorporation in bituminous mixtures: Application to the Cameroonian context

Wed, 25 Feb 2026 13:58:58 GMT

The valorization of plastic waste in road construction represents a promising solution to both environmental and infrastructure challenges in developing countries. This study investigates the mechanical, economic, and environmental performance of asphalt mixtures modified with recycled polyethylene terephthalate (PET) in the Cameroonian context. PET was incorporated into asphalt mixtures at different contents (0–7% by weight of bitumen), and the resulting mixes were evaluated using standard mechanical tests, including Marshall stability, flow, compactness, Marshall creep, and water sensitivity. The results show that PET modification significantly improves the mechanical performance of asphalt mixtures up to an optimal content of 5%, with an increase in Marshall stability, a reduction in permanent deformation, and satisfactory resistance to moisture damage compared to conventional asphalt. Beyond this threshold, mechanical performance decreases due to reduced workability and excessive stiffening of the mixture. An economic assessment indicates that PET-modified asphalt can reduce material costs by partially substituting bitumen, assuming local collection and processing of plastic waste. A simplified life cycle assessment (cradle-to-gate) focusing on energy consumption and greenhouse gas emissions highlights a net environmental benefit at optimal PET content, despite increased processing energy. The combined multicriteria analysis demonstrates that a PET content of approximately 5% provides the best compromise between mechanical performance, cost efficiency, and environmental impact. This study highlights the feasibility of integrating recycled PET into asphalt mixtures for tropical regions and provides practical guidance for sustainable road construction in sub-Saharan Africa.

Out-of-Plane Buckling Mechanism and Enhancing Method of Stiff Skeleton Arch Bridge When Wrapping Surrounding Concrete

Tue, 24 Feb 2026 09:01:00 GMT

This study investigates the stability of skeleton-reinforced concrete arch bridges during the concrete encasement process, employing a homogeneous generalized yield functions for extreme buckling load determination in nonlinear finite element analysis. Through an analysis of the stability of a stiff skeleton arch bridge with a 600 m span during the concrete wrapping stage, this study delves into and elucidates the mechanism by which the transverse brace enhances the out-of-plane stability capacity of the skeleton arch ribs. Additionally, a method for improving stability by controlling the lateral rotation angle of arch ribs is proposed. The results indicate that the lateral deflection angle of arch ribs serves as a crucial metric for assessing the out-of-plane stability of arch bridges. Transverse braces effectively coordinate and constrain the lateral deflections of two isolated arch ribs through their bending stiffness along the tangential direction of the arch axis. Notably, transverse braces within the range of L/8 to 3L/8 make the most substantial contribution to the lateral stiffness of arch ribs. Consequently, wrapping surrounding concrete on transverse braces within the L/8 to 3L/8 range proves advantageous for enhancing the stability of a stiff skeleton arch bridge under construction. Specifically, it is recommended to pour surrounding concrete on transverse braces at L/4 before the closure of the bottom plate’s concrete ring. After the ring of bottom plate’s concrete is closed, a symmetrical pouring of surrounding concrete on transverse braces from L/4 to the arch spring and vault is proposed.

Effects of NiO nanomaterial as a bitumen modifier on asphalt mixtures' performance against fatigue and low-temperature cracking in the presence of de-icer agents

Thu, 19 Feb 2026 10:53:37 GMT

Chloride-based de-icing salts are effective for winter road safety but raise environmental and economic concerns by accelerating asphalt deterioration through runoff, penetration, and chemical erosion. To counteract damage driven by deicer, this study examined nano-nickel oxide (nano-NiO) at 2 % and 4 % by weight as a PG 58–22 and PG 64–16 bitumen additive under moisture exposure caused by three common brine solutions: sodium chloride (NaCl), magnesium chloride (MgCl₂), and calcium chloride (CaCl₂). The experimental program employed semi-circular bending (SCB) tests at low temperatures (-10 and −20 °C), Pull-off tests at intermediate and low temperatures (-20, −10, 15, and 25 °C), and indirect tensile fatigue (ITF) tests at intermediate temperatures (15 and 25 °C). The results demonstrated that moisture conditions induced by de-icing agents significantly worsen the cohesion strength, adhesion resistance, fracture properties, and shorten the fatigue life of asphalt mixtures, with CaCl₂ showing the most detrimental effects. In contrast, incorporating 2 % and 4 % nano-NiO substantially improved these parameters; thus, the nanomaterial enhanced mixture integrity by reinforcing cohesion and adhesion bonds, thereby preventing crack formation and stress concentration. Mixtures modified with nano-NiO demonstrated greater resistance to failure at low temperatures. This was evidenced by an increase in the energy required to create a crack (fracture energy) and an increase in the critical stress intensity at the crack tip required for brittle fracture (fracture toughness). Furthermore, the modified samples showed an increased fatigue life (number of load cycles until final failure). Consequently, modified mixtures exhibited superior fatigue and fracture resistance when exposed to de-icing salts. Based on the statistical analysis, it was determined that bitumen modified with 4 % nano-NiO exhibited the best performance in enhancing bitumen-aggregate adhesion/cohesion at low and intermediate temperatures, improving the mixture's low-temperature fracture properties, and extending its intermediate-temperature fatigue life. Furthermore, the evaluation of the low- and intermediate-temperature performance of the base combinations tested in this study revealed that PG 64–16 bitumen, when used with limestone aggregate, produces a mixture with higher stability against the damaging conditions induced by de-icing chemicals. In summary, the results indicate that HMAs made with PG 64–16 bitumen modified with 4 % nano-NiO and limestone aggregate possess the greatest resistance to fatigue and thermal cracking in corrosive de-icing salt environments.

The impact of hydrophilic groups on the demulsification and interfacial behavior of cetyltrimethylammonium emulsified asphalt

Thu, 12 Feb 2026 08:53:23 GMT

Reducing carbon emissions and enhancing energy efficiency in road construction presents a significant challenge. However, the limited strength and slow demulsification rate of emulsified asphalt impede the wider adoption of cold-mix technologies. Current methodologies primarily focus on modifying emulsifier types and optimizing formulations, but often face difficulties in achieving a balance between stability and demulsification rates. This study systematically investigates cetyltrimethylammonium emulsified asphalt with varying hydrophilic groups through molecular dynamics simulations and experimental validation. Comparative analysis revealed that emulsifiers containing pyridine and bromide groups enhanced adhesion but slowed the demulsification process, whereas benzene-functionalized emulsifiers accelerated demulsification by weakening interfacial forces. The results demonstrated that HPB exhibited strong adhesion but slower demulsification, while HDBAC achieved the fastest demulsification with reduced adhesion strength. This research offers both a theoretical foundation and practical guidance for optimizing emulsified asphalt formulations, thereby contributing to the sustainable, low-carbon development of pavement engineering.

Enhancement of asphalt properties through SBS and CNT synergism: A comprehensive multi-scale analysis

Fri, 06 Feb 2026 13:54:23 GMT

Carbon nanotube (CNT)-modified asphalt, as a novel high-performance road material, has demonstrated significant application potential. However, the interface interaction mechanism and load transfer behavior between CNT and asphalt have yet to be systematically understood, which to some extent limits their engineering applications. To address this gap, this study combines molecular dynamics (MD) simulations, density functional theory (DFT), pull-out simulations, rheological tests, and direct tensile tests to systematically investigate the interface interaction characteristics and micro-mechanical behavior between Carbon nanotube, SBS-modified asphalt, and matrix asphalt from a multi-scale perspective. The results reveal that CNT can interweave with SBS molecules to form a stable mechanical anchoring structure, thereby enhancing the interfacial bonding between SBS and the asphalt matrix. Compared to SBS-modified asphalt, the SBS/CNT-modified asphalt exhibits a 75.17 % increase in Young's modulus in the Z-direction and a 30.35 % decrease in free volume fraction compared to matrix asphalt, indicating higher structural density and mechanical properties. DFT calculations further indicate significant π-π stacking interactions between CNT and asphalt molecules, which contribute to the overall stability of the system. Macroscopic mechanical tests show that the failure stress and fracture toughness of SBS/CNT-modified asphalt are 47.52 % and 125.17 % higher than those of SBS-modified asphalt, respectively. Additionally, Pearson correlation analysis reveals a significant positive correlation between fracture toughness and cohesive energy density and bulk modulus, further confirming the enhancing effect of CNT incorporation on asphalt crack resistance. In summary, this study elucidates the micro-mechanism of CNT-modified asphalt through multi-scale analysis and experimental validation, providing scientific and technical support for the design optimization and engineering application of CNT-modified asphalt materials.

Skid resistance evaluation of thin overlay asphalt mixtures based on three-dimensional texture reconstruction

Fri, 06 Feb 2026 13:54:23 GMT

Thin overlays, widely applied in road engineering to improve pavement smoothness and extend service life, generally demonstrate an initial decline and rapid deterioration in skid resistance. In this study, an optimized gradation design was conducted by adding supplementary sieve sizes of 5.6 mm, 6.7 mm, and 8 mm to enhance the skid resistance of the thin overlay asphalt mixture. The variation patterns of texture parameters featuring skid resistance were analyzed by three-dimensional reconstruction technology. Additionally, the road performance of the mixture was investigated through rutting tests and low-temperature bending tests. The skid resistance and its deterioration patterns were explored with pendulum tests, sand patch methods, and three-dimensional reconstruction technology. The results suggest that the optimized gradation-10, obtained by adding supplementary sieve sizes, exhibited better high-temperature stability and low-temperature crack resistance compared to SMA-10. The optimized gradation-10 also revealed superior performance in skid resistance decay, with a BPN attenuation rate of 21.7 %, which was lower than that of SMA-10 (29.9 %). Texture parameters, such as Sq, Sa, Ssk, Sku, Sdq, Sdr, Vmp, Vmc, and fractal dimension, reflect that the surface of the optimized gradation-10 had more peaks and valleys, greater texture depth, and sharper surface textures compared to SMA-10. Furthermore, correlation analysis specifies that Sa, Sdr, and Sdq were the primary texture parameters for characterizing skid resistance. Finally, regression equations for texture parameters, including EMTD-Sdr, MPD-Sdr, and BPN-fractal dimension, were established.