Transport Research International Documentation (TRID)

Reasons of the D47 Motorway Pavement Deformations Caused by Swelling of Metallurgical By-Products

Tue, 26 May 2026 09:41:01 GMT

Metallurgical by-products, primarily blast furnace and steel slag, have ranked among important alternative sources of fill as well as of material for the structural layers in highways. These are always artificial aggregates produced within the ironmaking or steelmaking process, or in the production of nonferrous metals.

Influence of alternative fuel from waste plastic oil on the macroscopic spray parameters utilising a single injection strategy in a piezoelectric diesel injector

Tue, 28 Apr 2026 17:06:30 GMT

An alternative way to utilise waste plastics is to use waste plastic oil (WPO) in diesel engines. One way to explore the potential of WPO as an alternative fuel in diesel engines is by determining the spray macroscopic parameters. The present research will study the spray macroscopic characteristics utilising WPO and ultra-low sulphur diesel (ULSD) as the fuel baseline. To do so, the spray macroscopic parameters will be characterised in a constant volume chamber under non-evaporative and non-reactive conditions and using injection pressures (pᵣₐᵢₗ) of 80, 100 and 120 MPa and a back pressure (pb) of 5 MPa. Among the main results reached, it can be highlighted that the spray tip penetration, spray cone angle, and spray area values of WPO are lower than those of ULSD in all injection pressure levels at the same time intervals after the start of injection. Moreover, analysing all macroscopic spray parameters and under the operating conditions studied, it can be concluded that the mixing process of WPO is faster than ULSD. Thus, WPO shows potential as an alternative fuel for diesel engines. Lastly, the present research provides useful information that may be used to support simulations of the injection process using WPO.

Rheological Characteristics of Waste Engine Oil-Modified Bituminous Binder

Tue, 28 Apr 2026 16:55:33 GMT

Bituminous binders encounter different distress during the life cycle of flexible pavement construction. Fatigue cracking and rut resistance are the most important characteristics of the binder. Addition of environmental-friendly modifiers/additives into the binder improves the rheological properties of bituminous binders. In this study, the effect of waste engine oil (WEO) on rheological characteristics of plain bitumen (VG30) as an additive was assessed through laboratory investigations. Also rutting and fatigue performance characteristics of the modified bitumen were investigated using Dynamic Shear Rheometer. From the Multiple Stress Creep Recovery test, the percentage recovery and Non-recovery creep compliance at different dosages of additive were evaluated. Linear Amplitude Sweep to determine G∗/sinδ and G∗sinδ indices for the bio-additive modified bitumen containing different percentages of WEO. The chemical properties of waste engine oil were identified by conducting Fourier Transform Infra-Red Spectroscopy. Overall it was found that WEO can be used as a softening agent to the aged bituminous binder.

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.

Exploring Asphalt Ageing: Evaluating Waste Cooking Oil as Asphalt Binder Rejuvenator

Mon, 27 Apr 2026 15:01:23 GMT

Ageing significantly influences the durability and performance of asphalt mixtures, making them vulnerable to cracking and deformation. To assess the ageing properties of asphalt mixtures, it is best to determine their binder performance. This paper offers a thorough analysis of the ageing characteristics and resistance of asphalt binders, specifically focusing on the incorporation of waste cooking oil (WCO) alongside Reclaimed Asphalt Pavement (RAP). The study employs a series of physical and rheological tests, as well as penetration, softening point, ductility, and dynamic shear test, to evaluate the degree of ageing exhibited by virgin, aged, and rejuvenated aged asphalt binders. The findings indicate that virgin asphalt binder demonstrates the highest degree of asphalt binder ageing, followed by the rejuvenated asphalt binder and aged asphalt binder, respectively. This result suggests that the additional of RAP and WCO serves to improve the asphalt binder’s ageing resistance. This is because the RAP binder is already aged, and WCO possesses an antioxidant that increases the asphalt ageing resistance. By utilising sustainable materials such as RAP and WCO in road construction materials, this research offers valuable insight into improving the longevity and performance of road construction materials by utilizing waste-derived resources in infrastructure development.

Application of Coal Bottom Ash as a Sustainable Waste Material in Warm Mix Asphalt – A Review

Mon, 27 Apr 2026 15:01:23 GMT

The application of waste materials and the uncertainty surrounding climate change are significant issues that highlight the need for creative reforms that will lead society toward a more sustainable future for all. The open dumping of Coal Bottom Ash (CBA) occupies a significant portion of valuable land and has a substantial consequence for the environment and humanity. To find a suitable method for handling CBA and enhancing our environments against excess contaminations, this study provides the application of CBA in Warm Mix Asphalt (WMA) and the bibliometric analysis of the study’s keywords. This article also reviews the contemporary technologies of previously published articles on WMA. Based on the previous publication on CBA by Scopus, China contributed 23.1% of the Scopus publications between 2016 and 2023, followed by Malaysia (15.4%) and Belgium (3.8%). This showed that China contributed the most in terms of the countries’ total contributions. Out of all the academic disciplines, materials science, engineering, physics, and astronomy have contributed 55.6%, 24.4%, and 20.0% to Scopus publications, respectively. Therefore, additional reviews are required to confirm CBA’s continued effectiveness in WMA.

Analysis of Palm Oil Fuel Ash, Garnet Waste and Sawdust as Modified Asphalt Binders and Mixtures

Mon, 27 Apr 2026 15:01:23 GMT

Given the increasing traffic loads and challenging environmental conditions, significant attention must be devoted to modified asphalt binders using waste materials. Therefore, this study investigated the preliminary analysis of palm oil fuel ash (POFA), garnet waste and sawdust as modified asphalt binders and mixtures. The process involved thorough evaluations regarding several aspects: the chemical features of individual waste, the physical properties of individual modified asphalt binders of 0%, 3%, 6% and 9% by weight of asphalt and the mechanical characteristics of individual modified asphalt mixtures. Consequently, the topmost chemical composition is initiated in POFA is Si2O, garnet waste is Fe2O3, and sawdust consists CaO. The findings showed superior stability of POFA-modified asphalt mixture proceeded along with garnet waste-modified asphalt mixture and sawdust-modified asphalt mixture. Thus, this outcome indicates a practical evaluation of the three types of waste, demonstrating good bonding and contributing to improved performance when used as a combination in asphalt modification.

Integration of Blue and Green Hydrogen Supply Chains for Road Mobility: Utilization of Byproduct Oxygen for Efficient Operation Through Optimization

Mon, 27 Apr 2026 15:01:18 GMT

Hydrogen is a key energy carrier in the transition to a sustainable, low-carbon future. Among hydrogen production methods, blue and green hydrogen are prominent, derived from non-renewable and renewable sources, respectively. This study explores the potential integration of these two supply chains to support hydrogen use in road mobility. First, a literature review is conducted to understand the characteristics of each supply chain. Then, a mono-objective, static and deterministic Mixed-Integer Linear Program (MILP) designs a supply chain network based on two cases to fulfill future road mobility demand in Qatar, although the model itself can be applied outside Qatar as well. In the first case, only blue hydrogen can be produced, and Auto-Thermal Reforming (ATR) pathway is selected. In the second case, the model can incorporate both green and blue pathways, with the green pathway chosen. Through literature review, it was also highlighted that Air-Separation Units (ASUs) represent a major capital cost in ATR plants, whereas oxygen from electrolysis is typically vented. This opens the possibility of using this electrolytic by-product oxygen in ATR, suggesting that integrating blue and green hydrogen supply chains could reduce overall network costs which warrants further study.

Innovative Logistics of Spent Coffee Grounds Reuse: An IoT-Based Rolling Horizon Approach

Mon, 27 Apr 2026 15:01:16 GMT

Coffee is one of the most consumed beverages worldwide, driving an industry worth billions of euros annually. However, its life cycle does not end with consumption; it generates a significant amount of by-products, including spent coffee grounds (SCG), often treated as waste. If managed through innovative recovery and reuse practices, these by-products can be recycled and transformed into valuable resources, reducing environmental impact, and optimizing logistics processes. This research explores the recovery of SCG as secondary raw materials in other production chains, leveraging IoT technologies and web-based platforms for real-time monitoring and informed decision-making. The study proposes a heuristic approach that simultaneously plans coffee deliveries and SCG collections (pick-ups) and related routing for a set of coffee shops, while dynamically adapting to evolving requests through a Rolling Horizon technique. Performance results on test cases based on extensive territorial and realistic consumption data are promising, highlighting the potential of this approach for sustainable supply chain management.

Response Surface Methodology-Based Optimization of Rice Husk Ash and Ground Granulated Blast Furnace Slag Dosage for Alluvial Silty Soil Stabilization

Thu, 23 Apr 2026 09:10:01 GMT

The low strength and large void ratio of alluvial soil (silty) represent a poor quality of subgrade that shows early distress, causing the premature failure of pavement. To enhance the performance of the soil in this context, a mixture of additives such as ground granulated blast furnace slag (GGBS) and rice husk ash (RHA) was applied. Researchers are now very interested in the optimal dosage of stabilizers for increased strength and cost-effectiveness in construction. The dosages analyzed were 5%–12.5% GGBS and 0%–7.5% RHA by weight of dry soil. The following response values were considered: optimum moisture content (OMC), elastic modulus (EM), California bearing ratio (CBR), and unconfined compressive strength (UCS). EM was derived using a novel method of light weight deflectometer testing on the CBR mold. To find the optimal dosage of RHA and GGBS to be added simultaneously for soil stabilization and to examine how these substances affect the soil, response surface methodology models were generated, giving the optimal RHA and GGBS dosages as 2.05% and 7.18%, respectively, to meet desired soil performance. According to the findings, adding GGBS and RHA increased the soil’s strength because of the production of cementitious compounds by pozzolanic reactions, as demonstrated by the mineralogical and morphological examinations of soil specimens. The stabilization resulting from optimal dosages improved the soil UCS by 177%, EM by 47%, and CBR by 242%, and reduced OMC by 4%. This study can provide a strong foundation for effective soil use in road building.

Utilisation of construction and demolition waste in granular sub-base along with scrap tyre cellular reinforcement: a sustainable practice

Wed, 22 Apr 2026 16:15:30 GMT

This study explores the use of recycled materials such as recycled asphalt pavement (RAP) and recycled concrete aggregate (RCA) in the granular sub-base (GSB) layer, incorporating scrap tyres as cellular reinforcement. Laboratory repeated load tests are conducted on model pavement sections under both unreinforced and scrap tyre cell (STC) reinforced conditions. The results indicate that RAP sections experienced significant rutting within the initial 500 load cycles, suggesting a lower load-bearing capacity unsuitable for GSB application over the weak subgrade. Meanwhile, RCA demonstrated comparable performance to natural aggregates, making it a viable replacement. The integration of STC reinforcement proved effective in confining GSB materials, thereby enhancing pavement performance by reducing the plastic deformation and residual pressure at the subgrade level compared to the respective unreinforced section. Overall, the study recommends the use of scrap tyres and RCA in GSB providing cost-effective, sustainable, and environmental friendly pavement solutions.

Polymer Modification of Asphalt with Recycling By-Products of Polyurethane Foam as Asphalt Extender

Tue, 21 Apr 2026 14:30:16 GMT

Waste polyurethane (PU) can be degraded into polyols for recycling through alcoholysis, effectively addressing environmental pollution and solid waste management challenges. However, substantial byproducts of polyurethane foam recycling (BPF) are generated. Previous research has proved that BPF can be used as an asphalt extender, by adding 10 wt% of base asphalt to produce BPF-asphalt with comparable or even superior performance compared with base asphalt. However, BPF-asphalt struggles to meet the stringent requirements of high-grade pavements, so polymer modification is crucial for enhancing its performance. In this study, styrene-butadiene-styrene (SBS) modified BPF-asphalt (SMBA) was prepared with BPF, SBS, and sulfur as asphalt extender, modifier, and stabilizer, respectively. A comprehensive performance investigation for SMBA was conducted considering the influence of the composition of BPF and the potential reaction between BPF and sulfur. The results show that SBS modification can enhance the performance of BPF-asphalt, particularly addressing its defect on rutting resistance. Notably, the road performance of SMBA is closely related to the addition sequence of additives: adding SBS and stabilizer before BPF yields optimal results with superior storage stability. This is because the -NH₂ group in BPF can react with sulfur in the stabilizer. The delayed BPF addition preserves network integrity while forming stable SBS-aromatic amine-asphalt adsorption structures. SMBA generally exhibits inferior high-temperature performance compared with conventional SBS asphalt due to BPF’s viscous components. Only BPF containing PS forms an interpenetrating network with SBS through thermal polymerization, thereby achieving enhanced thermal stability. This study demonstrates the feasibility of using BPF as asphalt extender for SBS modified asphalt, which not only alleviates the treatment pressure of waste polyurethane foam (PUF) but also promotes sustainable road infrastructure development.

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.

Biochar Design Guidance

Fri, 10 Apr 2026 10:52:06 GMT

Minnesota Department of Transportation (MnDOT) would like to develop a design manual that provides specific or standard specifications and design information for using biochar on projects and sought to gather information from other agencies to assist them. To help MnDOT understand biochar practices used by other agencies, this project: (1) interviewed a MnDOT employee to identify key issues, (2) developed and distributed an online survey to DOTs, state agencies, professional organizations, and consultants, and (3) conducted follow-up interviews with three experts in biochar design guidance and specifications. Biochar is being used as a soil amendment in stormwater management best practices (BMPs) to reduce nutrients, sediment, and to capture bacteria in stormwater runoff. Biochar is also being used as a soil amendment to enhance plant and tree growth in urban settings. This research synthesis summarizes the findings from the survey and interviews.

Evaluation of Foamed Glass Aggregate for Roadway Embankment Applications

Thu, 09 Apr 2026 09:01:27 GMT

Lightweight fill materials play critical roles in building infrastructure on challenging sites. Foamed glass aggregate (FGA) is a lightweight option that has attracted much attention lately. FGA is a processed recycled aggregate made from waste glass. The process involves grinding the glass into powder and melting it at a high temperature (e.g., 1,600°F) with a foaming agent (e.g., 2% by weight). In addition to its low compacted unit weight, FGA possesses several unique engineering properties, such as a high friction angle, good thermal insulation, high permeability, easy placement, and so forth. With these properties, the utilization of FGA could be a sustainable practice that contributes to the reduction of fill settlement over soft ground and environmental preservation by the reuse of waste glass. However, as with any emerging or unconventional material, a comprehensive engineering study of FGA is essential before its widespread application to prevent unsatisfactory performance. To that end, two types of FGA material (produced using either a dry or wet foaming agent) and two conventional soils (sand and clay, used as references) were procured for laboratory experiments. These experiments covered basic FGA characteristics, including gradation and volumetric properties, followed by mechanical properties such as axial compression compaction, one-dimensional consolidation, dynamic triaxial, and direct shear. In addition, a pilot fill construction was undertaken using FGA to determine the field compaction acceptance criteria. Results indicated that FGAs are viable lightweight fill materials. Further research is needed to monitor FGA performance through full-scale construction projects.