Transport Research International Documentation (TRID)

Investigation of Low Friction on Asphalt Pavements

Tue, 05 May 2026 13:15:58 GMT

This study explores low-friction issues in specific asphalt pavements utilizing dolomite aggregates within an Indiana Department of Transportation district. It examines the frictional characteristics of these aggregates, concentrating on initial friction (PSV0) and long-term friction retention (PSV10). Employing a mix of laboratory tests, field data analysis, and statistical modeling, the research assesses how mechanical, physical, and chemical properties influence the overall friction behavior of dolomite aggregates. The evaluation of Design Mix Formulas (DMFs) revealed no statistically significant effect on pavement friction, with variations more closely tied to aggregate quality and construction practices rather than the mix design itself. Inconsistent friction results were observed in projects using the same DMF, underscoring the importance of aggregate quality. The transition from Superpave4 to Superpave5 showed no correlation with friction outcomes. Chemical property analyses highlighted magnesium (Mg) content as critical in determining initial and retained friction performance, identifying an optimal Mg range of 11.35%-12.63% (MgO: 18.82%-20.94%) for a balance between initial friction and long-term durability. Field samples were compared with laboratory results, indicating that low PSV0, rather than excessive wear, primarily contributed to low friction in certain road sections. Additionally, a moderate correlation (0.51) between friction loss (ΔPSV) and average annual daily traffic (AADT) suggests that high-traffic roads are more prone to polishing effects. The study also assessed the role of secondary aggregates, such as steel slag, in improving friction retention, proposing that blended aggregates may enhance long-term performance. Recommendations include optimal Mg content thresholds, effective aggregate selection strategies, and enhanced quality control and assurance measures during construction. Emphasizing the need for adequate aggregate angularity and the inclusion of steel slag, these findings provide a foundation for future research and policy development aimed at improving long-term pavement friction performance.

Legitimate and Pioneering Technologies for Construction & Maintenance of Roads

Tue, 05 May 2026 13:15:58 GMT

Need for such highway innovations stems from necessity for highway to become more genuine, adaptive, efficient, authentic and responsive to changing demands to move quickly/easily. Integration of New Technologies are vital for incorporating "smart" technologies to make it a flexible, customer-centric and sustainable. Legitimate technologies refer to established rules, laws, or IRC/IS/International standards, and pioneering technologies refers to breaking new ground, innovating, and operating in uncharted/unfamiliar/unexplored territory. Various such innovative technologies viz use of waste plastic, cold/warm mix technologies, jute/coir geo textile, geogrid coated with PMB (Polymer Modified Bitumen), fully mechanised pavers for recycling of asphalt pavement, ultra-high performance concrete, glass fibre reinforced polymer bars and sheets as per IRC:137-2022/IS:18256- 2023 and IS 14856:2000 respectively in case or marine environment to make transportation very easy due to light in weight, use of Construction and Demolition (C&D) waste, very advanced material i.e. geopolymer, recycling of asphalt pavement, high performance bituminous pavements IRC:SP:139-2023 SUPERPAVE, determination of interlay shear strength of tack/prime coat, performance tests on asphalt mixes, determination of surface area of aggregates and thereby thickness of bituminous layer over aggregates (specified value is 6-8 micron as per IRC:SP:135-2022), use vacuum technology in automatic oven directly giving binder/moisture content, use of bamboo piling and vacuum technology in Prefabricated Vertical Drains (PVD) to accelerate consolidation for ground improvement using vacuum technology, short panel concrete pavement IRC:SP:140-2024 particularly in new pavement, gradients and hilly areas where temperature stresses are higher, white topping over damaged asphalt pavement, bonded rigid pavement on gradients, and advanced digital/robotic mainly in tunnel, quality control with the help of drone system, use of RFID in the manhole covers etc to avoid theft and bio technologies are gaining momentum these days and being applied in the field in road construction as well. Further, new age binders in road construction primarily refer to sustainable and performance-enhanced alternatives to traditional petroleum-based bitumen. The viscosity grade bituminous binders may beknow modified with graphene/ultra fine/nano size mineral admixtures or alternatively pyro based using waste rubber or biobased bituminous materials may be also adopted to improve performance and sustainability with less reliance on fossil fuels/environmental impact. The paper thus describes innovative technologies saving time, space, energy, improving environment, minimising pollution. There will be literally saving of conventional materials viz cement, soil, natural aggregates and steel/aluminium.

A comparative assessment of the bearing capacity of unselected construction and demolition waste aggregates in unbound and cement-stabilised pavement subbases

Wed, 29 Apr 2026 09:10:30 GMT

Using unselected construction and demolition waste (UCDW) aggregate helps the road construction industry to meet sustainability requirements. Although the use of recycled UCDW aggregates is increasingly recognised and adopted in practice, there remains limited field evidence directly comparing their performance with that of natural (NAT) aggregates in unbound and cement-stabilised subbases. This study compared the bearing capacity of four 30-cm subbases (unbound and 3% cement-stabilised NAT and UCDW) using lightweight deflectometer and plate loading tests on an experimental road. The study was complemented by laboratory resilient modulus and indirect tensile strength measurements on specimens compacted during the construction activities.On average, the surface modulus of unbound UCDW materials was 16% higher than that of natural aggregates. Stabilisation with 3% cement significantly increased the bearing capacity sevenfold for UCDW materials and tenfold for NAT materials. After three days of curing, the average surface modulus increased from 112.3–126.6 MPa for unbound UCDW and 95.2–111.6 MPa for unbound NAT, to 884.7–1024.6 MPa for cement-stabilised UCDW and 1064.3–1198.1 MPa for cement-stabilised NAT. Unlike the field tests, where cement-stabilised NAT performed slightly better than cement-stabilised UCDW, the laboratory tests showed that cement-stabilised UCDW mixtures had a higher resilient modulus than cement-stabilised natural ones. These results demonstrate that UCDW aggregates can effectively replace natural ones in the formation of unbound or cement–stabilised road subbase layers.

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.

Effect of Cement and RAP Content on Full Depth Reclamation (FDR) of Low-Volume Roads: A Response Surfaced-Based Study

Tue, 28 Apr 2026 16:55:33 GMT

Full depth reclamation (FDR) of asphalt pavements is a sustainable and economical rehabilitation technique used worldwide. Typically, in any FDR process, recycled materials from pavement layers are mixed with a chemical additive like cement to increase the strength and stiffness of the layer. Additional material in the form of RAP and aggregates is used if the desired depth or gradation is not achieved. This study tries to assess the compressive strength characteristics of FDR by considering open graded premix carpet (OGPC) as RAP material and understand the effects of RAP and cement through statistical methods. FDR specimens were fabricated in the laboratory considering a typical low-volume road composition used in India. The response surface method was employed for the experimental design and development of a response model for FDR compressive strength. Laboratory investigation included unconfined compressive strength (UCS) determination at various test conditions as per the design of the experiment. Results showed that the compressive strength of FDR was within limits specified for a treated granular layer using nominal cement contents for the in situ gradation considered for a full depth reclamation. ANOVA analysis showed that the effects of cement and RAP were significant, whereas the interaction between cement and RAP was not significant within the range of testing. However, the effect of cement was more prominent as compared to the effect of RAP. Further, the response model developed showed good capability for predicting the UCS values within the range used to develop the model.

Micro-mechanical and environmental assessment of jarosite waste and limestone powder-treated clay soil for embankment applications

Wed, 22 Apr 2026 16:15:30 GMT

This study explores the innovative use of industrial by-products, specifically jarosite waste and limestone powder, for stabilising clay soil and its applicability as an embankment material. Laboratory tests were performed to assess the expansive behaviour of soil samples, and microstructural analyses were conducted to study the stabilisation mechanisms over a curing period ranging from 0 to 28 days. The unconfined compressive strength (UCS) of the samples was measured at curing durations of 0, 7, 28, and 91 days. Additionally, potential toxicity levels associated with jarosite waste were evaluated using inductively coupled plasma mass spectrometry. The soil treated with 20% jarosite waste and 7.5% limestone powder has been found to satisfy the required strength, plasticity index (PI), and swelling pressure (SP) criteria according to the relevant codal provisions for embankment material.

An experimental study of the effect of mineral hardness contrast in aggregates on long-term pavement friction

Wed, 22 Apr 2026 16:15:30 GMT

This study emphasises the significance of aggregate hardness contrast in influencing long-term pavement friction. Eight types of aggregates with varying quartz content were tested. Mosaics built with the selected aggregates, representing pavement layers, underwent polishing tests to evaluate their long-term friction. The results revealed a parabolic variation, peaking at 50% quartz, confirming that the Aggregate Hardness Parameter is crucial for long-term pavement friction. Consequently, long-term pavement friction relies on significant hardness variation among aggregate minerals, rather than solely their average hardness. This finding contradicts the well-established view that a higher quartz content in aggregates consistently enhances their long-term friction retention.

Comparative assessment of limestone-calcined clay blend and fly ash as binders in roller-compacted concrete pavement: evaluation of fresh and hardened properties

Wed, 22 Apr 2026 16:15:30 GMT

This study presents a comparative analysis of cement replacement with a limestone-calcined clay blend (LC2) and fly ash (FA) in roller-compacted concrete pavements (RCCP) at substitution levels of 25–80%. The results indicate that increasing replacement levels raised optimal moisture content, with LC2 mixes requiring less water than FA mixes, ranging from 7.13% to 21.77% compared to 16.38% to 28.71%. As a result, LC2 provided a controlled increase in consistency, air content, and density loss, ensuring a well-compacted matrix. In contrast, FA led to higher moisture sensitivity, greater air retention, and increased density loss. At 28 days, RCCP mixes with 50% LC2 exhibited a minimal compressive strength reduction of 3.52%, significantly outperforming those with 25% FA, which suffered a 19.20% reduction. While FA maintained RCCP strength requirements only up to 25% replacement, LC2 remained effective even at 60%, demonstrating its viability as a superior cement alternative in RCCP applications.

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.

Fly ash and natural rubber latex modified recycled aggregate concrete as sustainable rigid pavement surface

Tue, 21 Apr 2026 14:30:16 GMT

An integration of Recycled Concrete Aggregate (RCA) and Fly Ash (FA) into concrete represents a practical solution for sustainable construction by minimizing the use of natural resources and lowering carbon emissions. This research investigated the effects of incorporating Natural Rubber Latex (NRL) into FA-RCA concrete mixtures on both mechanical properties and environmental performance as a greener pavement concrete. Experimental evaluations included compressive strength (fc), flexural strength (ff), flexural fatigue behavior, and microstructural analysis using Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray spectroscopy (EDX). In addition, total CO₂-equivalent emissions were calculated based on the emission factors of each mix constituent. Results showed that moderate NRL content (r/b = 0.5–1.0 %) improved ff and fatigue life, particularly at FA replacement levels of 15–25 %, while higher r/b ratios led to diminished strength due to hydration retardation. SEM and EDX analyses revealed enhanced microstructural densification at optimal NRL dosages, while excessive latex introduced film barriers, limiting hydration. Furthermore, replacing cement with 25 %FA and 0.5 %r/b resulted in the lowest emissions (304.63 kg CO₂-e/m³) and the greatest fatigue life at 56 days (2863 cycles), whereas 20 %FA provided the most cost-efficient option (53.48 USD/m³); all mixes satisfied the Thai pavement strength requirements. The findings confirm that careful optimization of NRL and FA content in RCA-based concrete can simultaneously improve structural performance and reduce carbon footprint, supporting the development of low-carbon pavement surface materials.

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.

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.

Design and performance characterization of porous steel slag asphalt pavement for traffic noise reduction

Wed, 01 Apr 2026 11:46:20 GMT

Rising road traffic volumes are exacerbating road noise pollution. The pursuit of pavements with superior noise reduction efficacy has become a critical strategy for mitigating this issue. As an industrial solid waste, steel slag (SS) possesses a textured and micro-porous surface structure, which grants it promising sound-absorption capabilities. The study initially investigated the pore and texture structures of SS surfaces before and after aging. The results revealed that these structural characteristics remain well-preserved post-aging. Furthermore, the aging process promotes the formation of beneficial cementitious gels that enhance the stability of the porous pavement structure. Subsequently, sound absorption coefficient tests demonstrated that SS porous asphalt mixtures exhibited a 7.6 % higher peak absorption coefficient compared to basalt and limestone mixtures. Ultimately, Indoor tire-drop tests revealed that aged SS porous asphalt mixtures consistently outperformed both natural aggregate porous mixtures and unaged SS mixtures in noise reduction. This finding demonstrates that SS possesses significant inherent noise reduction capabilities due to its material characteristics. These findings demonstrate the significant application potential of SS as aggregate for low-noise porous asphalt pavements.

Application of Waste Cooking Oil–Steel Slag in Dry Process Preparation of Rubber Asphalt Mixtures

Thu, 26 Mar 2026 17:03:06 GMT

This study explores using steel slag as a substitute for natural aggregates and waste cooking oil in the dry-mixing rubber asphalt mixture. First, the feasibility of steel slag as a replacement for aggregate was analyzed using scanning electron microscopy observation. Then, the oil-stone ratio of the dry-mixing rubber asphalt mixture with varying steel slag contents was determined based on Marshall test results. Furthermore, the optimal dosage of waste cooking oil as a rubber activator was evaluated to enhance the performance of the dry-mixing steel slag rubber asphalt mixture. The working mechanism of steel slag as a substitute for natural aggregate and waste oil in the rubber asphalt mixture was analyzed through rutting, immersion Marshall and freeze-thaw splitting, low-temperature beam bending tests, and scanning electron microscopy (SEM). The testing results show that the performance of the dry-mixing steel slag rubber asphalt mixture with waste cooking oil is better than the mixture without waste cooking oil. The asphalt thoroughly penetrates into the surface porous of the steel slag, potentially improving the adhesion between the asphalt and steel slag. The optimal combination for the dry-mixing rubber asphalt mixture is a 50% substitution rate for steel slag and a 4∶1 ratio of rubber powder to waste cooking oil, providing a reference for transforming resource utilization in road construction.

Performance-informed life cycle assessment of waste-derived asphalt mixtures for full aggregate replacement

Thu, 26 Mar 2026 09:05:15 GMT

Increasing the circularity of asphalt pavements through industrial by-products and reclaimed asphalt pavement (RAP) offers a practical route to reduce reliance on virgin aggregates and the associated upstream burdens. This study presents an integrated sustainability evaluation of steel slag-RAP asphalt mixtures designed for full aggregate replacement, combining laboratory performance characterisation with a performance-informed life cycle assessment (LCA). Laboratory testing covered key road-performance attributes, complemented by immersion conditioning and trace-element leaching to examine long-term feasibility and environmental safety. A high-functionality epoxy slag-RAP mixture was identified through performance screening and adopted as the representative full-replacement option for scenario parameterisation. The LCA quantified seven impact categories and a monetised ecological cost indicator, with results interpreted under a functionally consistent 30-year comparison. Under this comparison, the full-replacement option reduced global warming potential from 146.01 to 89.42 t CO₂-eq (−38.8%) and acidification from 0.58 to 0.36 t SO₂-eq (−37.9%) relative to a conventional natural-aggregate reference, with the benefits arising from both waste-based aggregate substitution and reduced intervention frequency enabled by improved durability; trade-offs were observed in eutrophication and toxicity-related indicators. Total ecological cost decreased from 182.30 × 103 CNY for the conventional reference to 113.59 × 103 CNY for the full-replacement option. By integrating performance-based service-life parameterisation with multi-category life cycle impact and ecological-cost monetisation, the proposed framework supports a more accurate and comprehensive evaluation of recycling-based pavement strategies and can be transferred to other infrastructure applications, while confirming that full replacement of natural aggregates by waste-derived materials can deliver substantial net life-cycle benefits.