This study presents an analysis of potentially sustainable road construction technologies using lignin as a bio-based modifier and bio-binder (a tall oil derivative) to replace conventional asphalt binder. The research focuses on evaluating the influence of these materials on the carbon footprint and mechanical properties of asphalt mixtures. The system boundary of the Life Cycle Assessment (LCA), focusing specifically on the carbon footprint, includes raw material production, transportation, and asphalt mixing at the plant. Global Warming Potential (GWP) is expressed for 1 m3 of mixture. The results demonstrate that the substitution of conventional asphalt binders with biobased materials did not consistently establish a net climate benefit under the evaluated conditions. The Brazilian scenario exhibited contrasting results, highly sensitive to accounting methodologies employed for carbon capture from biogenic sources and release. The Ukrainian scenario showed a slight reduction in emissions, highlighting the potential of biobased modifiers, such as lignin, to reduce carbon footprints when combined with conventional binders.
India’s growing highway development requires sustainable pavement solutions aligned with national carbon-reduction goals. This study evaluates the environmental performance of Bituminous Concrete (BC-II) mixes incorporating 0–40
This study estimates yearly greenhouse gas (GHG) emissions of a test road comprising 8 sections in a full-factorial 23 design: 2 different wearing course mixtures (standard SMA and thin SMA), 2 binder types (penetration grade and polymer modified bitumen), and 2 levels of bio-oil (with and without) as bitumen extender. Using an existing contracting model, GHG emissions from the construction phase (including materials, production and paving) are allocated to the estimated life-length of each test section. The life-lengths are determined from laboratory rutting performance based on prall studded tire wear and wheel-track tests. In conclusion, binders with added bio-oil exhibit similar laboratory characteristics as their conventional counterparts. Paving thinner wearing courses and incorporating bio-oil significantly reduced GHG emissions in the construction phase. However, the contractual life-length-model suggests that standard SMA is preferred over the thin SMA due to lower rate of rutting and consequently lower annual emissions.
This study presents an Integrated Cradle-to-Gate Embodied Energy and Construction Cost Assessment of LDPE-Modified Asphalt Pavements. It compares the cost and energy requirements of pavements constructed using LDPE through wet and dry methods, these results are further compared with the pavements containing only virgin VG 40 binders. Pavement sections were designed and analyzed using elastic layered theory, and for both methods performance was evaluated relative to conventional mix. Inventory data involving material production, mixing, transportation, and construction phases were collected from construction and implementation agencies. The results indicate that the inclusion of LDPE significantly enhances mixture’s resilient modulus, leading to reduced thickness of asphalt layer. Pavements incorporating LDPE-modified binders via the wet process exhibited up to 19
For over 50 years, polymeric asphalt reinforcement grids have been used to delay or prevent reflective cracking in pavement rehabilitation. Their proven performance extends maintenance intervals, reduces traffic disruptions, and delivers substantial environmental benefits by conserving resources and reducing total emissions. By presenting a practical case study to calibrate improvement factors, this paper demonstrates the long-term impact of reinforcement on pavement performance, on both technical and environmental levels, alongside with a detailed calculation of CO2 savings between reinforced and unreinforced rehabilitation methods.
Volatile Organic Compounds (VOC) emitted from asphalt pavements during their in-use phase are increasingly recognized as contributors to atmospheric pollution, particularly in urban environments. Yet, the influence of operational parameters such as temperature and asphalt composition on these emissions remains insufficiently quantified. In this study, a laboratory-scale protocol was established to investigate VOC release under controlled thermal conditions using a custom-built climate chamber composed of perfluoroalkoxy alkane (PFA) material. Two commonly used French asphalt mixtures used as wearing courses, “Béton Bitumineux Semi-Grenu” (BBSG) and “Béton Bitumineux Très Mince” (BBTM), were tested at three temperatures: 20, 55, and 70 °C. VOC concentrations were monitored in real time using a photoionization detector (PID), and emission rates were expressed as time-resolved emission factors normalized by the exposed surface area and mass of the specimens. The results revealed a pronounced increase in emissions with temperature, consistent with thermally activated diffusion and desorption processes. In addition, differences between BBSG and BBTM were observed despite the use of the same binder, indicating that aggregate structure and other physicochemical properties play a significant role in emission behavior. This methodology provides a reproducible and quantitative framework measuring and evaluating VOC emissions from asphalt materials under climate-relevant conditions, supporting improved material design and environmental assessment in pavement engineering.
Composite materials (including paper, plastic, and aluminum) are commonly used for beverage cartons. Regarding their end-of-life management, after paper recovery, residues can be valorized to produce a granular material (recycled plastic) that can be incorporated into asphalts. The addition of plastic enhances the mechanical performance of asphalts, improving resistance, durability, and flexibility. A life cycle assessment was conducted to evaluate the potential benefits of using a pavement made of an asphalt mixture incorporating 2
This study evaluates the environmental performance of asphalt mixtures manufactured with three binder types: conventional asphalt cement (AC 30–45), crumb rubber–modified asphalt, and SBS polymer–modified asphalt. It was considered the raw material extraction and production stage (life cycle phase A1). The analysis investigates how mixture design, particularly binder content, influences the carbon footprint and identifies opportunities for emissions reduction in pavement engineering. Results reveal a clear linear relationship between binder content and the carbon footprint of the mixtures. When emissions were normalized by indirect tensile strength, however, the three binder types exhibited comparable ranges of CO2-eq per MPa, underscoring the importance of incorporating mechanical performance into environmental assessments. Overall, the findings emphasize the relevance of dematerialization strategies and the use of low-carbon materials during phase A1. Integrating environmental evaluation in the design stage, considering binder content, aggregate gradation, and recycled inputs, can support more sustainable pavement solutions.
Bituminous pavements are widely used worldwide, but their production and laying release hazardous fumes, including volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). These emissions pose risks to human health, ecosystems, and the environment, highlighting the need for effective mitigation strategies. This study investigates the use of hydrochars from two different waste sources (plant biomass and sewage sludge) as sustainable additives to reduce bitumen fume emissions. Virgin 70/100 bitumen was modified with 10 wt
Utilizing waste plastics in asphalt mixtures offers a potential solution for sustainable pavement construction and waste reduction. However, despite these benefits, their potential environmental consequences remain insufficiently understood. This study investigates the emissions and performance characteristics of plastic modified asphalt (PMA) that incorporates waste low-density polyethylene (LDPE) using the dry process. To evaluate environmental effects during mixing, emissions of volatile organic compounds (VOCs) and particulate matter (PM2.5 and PM10) were monitored. In parallel, the mechanical performance of the mixes was evaluated through Marshall stability, flow, quotient, voids in mineral aggregate (VMA), and voids filled with bitumen (VFB). The PMA exhibited greater stability than the control mix, indicating enhanced strength and interlocking. However, VOC emissions rose with increased LDPE content, particularly at 8
In recent years, the debate surrounding energy savings and emission reduction in road construction has gained momentum. Not least since Germany made the introduction of low-temperature asphalt (WMA) mandatory the use of this technology has also gained importance in other countries. In Switzerland, various research and practical experiences in the field finally highlighted its potential regarding sustainable and environmentally friendly construction. A new research project “Warm mix asphalt optimization with regards to RAP addition” with the aim to identify WMA-RAP mixtures with properties comparable to or better than those of conventional HMA by using different WMA technologies could proof the concept, stating equal mechanical performance in terms of rutting and cracking especially for plant produced WMA-RAP mixtures.
The paper presents the low-temperature assessment of asphalt mixtures with use of highly polymer modified bitumen (HiMA) and reclaimed asphalt pavement (RAP) after short-term aging and long-term aging procedures. The influence of aging, warm mix asphalt (WMA) and 30
Low-volume traffic roads (LVTR) constitute an essential component of economic infrastructure and require further development using alternative materials. This research focuses on comparing dense-graded half-warm asphalt mixtures for LVTR, fabricated using neat paving heavy crude oil—a natural liquid asphalt—from Castilla field oil (Colombia) (PHCO-CA) and nano-modified PHCO-CA. Results suggest that the adhesion quality (assessed by surface free energy) of the binder-aggregate interfaces decreased with the addition of the nano-modifier. In addition, the mix design parameters suggest that the nano-modifier improved the material's compactability but negatively affected the mixture's mechanical response. Moisture damage susceptibility was affected by the type of mineral filler rather than nano-modification. Future research can focus on exploring additional nano-modifier contents and corresponding changes in mixture response, including mechanical response (e.g., stiffness) and durability (i.e., aging) to support further paving applications of the PHCO-CA.
The incorporation of biopolymeric capsules into asphalt mixtures is a novel technique to enhance self-healing properties and improve pavement durability. There are two main experimental tests that have been developed to assess the effectiveness of this technique: (i) fatigue-healing (microcrack scale) and (ii) fracture-healing (macrocrack scale). In both cases, the healing capacity of the material is assessed using a healing index (HI), defined as the ratio of a testing parameter measured after and before the appearance of cracks for a given healing period. This study evaluates the self-healing behaviour of long-term aged asphalt mortars, with and without capsules, using a recovery period of 24 h at temperatures of 22 ℃ and 45 ℃. The main results show that, for both methods and in most cases, the presence of capsules enhanced the intrinsic self-healing capacity of the asphalt mortars, especially at high temperatures.
Warm Mix Asphalt (WMA) technologies, including wax- and chemical-based methods, have been increasingly studied in Taiwan. However, the lower mixing and compaction temperatures can reduce rutting resistance and affect aging behavior. Polymer Modified Binder (PMB) was therefore added to improve WMA performance. AC-20 served as the control binder, and three polymers—Styrene Butadiene Styrene (SBS) (A, B, C), Styrene Ethylene Butylene Styrene (SEBS), and Styrene Isoprene Styrene (SIS)—were tested at 3
Porous asphalt (PA) is commonly used in the wearing courses of Italian motorways due to its effectiveness in promoting rainwater drainage and enhancing skid resistance under wet conditions. However, PA is particularly susceptible to ravelling, a surface degradation process primarily caused by tire–pavement interaction during vehicles’ movements. This study evaluates the ravelling resistance of warm PA mixtures containing 15
Self-healing of asphalt mixtures with encapsulated rejuvenators is a promising method to extend the service life of asphalt pavements. This study investigates the mechanisms and factors that control capsule activation and the associated healing process. To reach this goal, fatigue-healing tests were conducted at two scales: i) asphalt mortar and ii) asphalt binder. For the mortar, a healing index (HI) was measured on long-term aged specimens without and with capsules using a resting period of 24 h at 22 ℃ and 45 ℃. For the binder, long-term aged asphalt binder with and without the addition of oil were tested, and an equivalent HI was calculated after a 30 min recovery at 5 ℃ and 22 ℃. The mortar tests capture capsule activation under realistic, field-like conditions and healing under relatively favourable conditions (i.e., intermediate to high temperatures). In contrast, the binder tests evaluate the effect of the released rejuvenator on healing under less favourable conditions (i.e., intermediate to low temperatures). The results provide new insights into the mechanisms of capsule activation and the healing process within these systems.
Chemical ageing is a major contributor to performance deterioration and failure in asphalt applications. The bituminous binder is particularly susceptible, with initial reactions occurring at the material surface. To assess the influence of binder composition on durability, laboratory photo-ageing experiments are commonly applied. However, most studies focus on bulk rheological or chemical changes, which limit their sensitivity to surface-specific degradation since large portions of the sample are not directly exposed to radiation. This study presents a simple method to determine UV-ageing rates of bituminous binders based on chemical changes at the surface. Solid-state fluorescence spectra were recorded successively for 60 cycles using a constant excitation wavelength of 365 nm, capturing the radiative response of the auto-fluorescent material in the 450–800 nm range. By evaluating the decrease in fluorescence intensity, the time-resolved degradation of different binders was quantified as a function of binder source, ageing state, polymer modification, and bio-modification. Results show that initial degradation in virgin and SBS-modified binders was highest, though variable between sources. Reclaimed Asphalt Pavement (RAP) binders exhibited no further measurable fluorescence changes. Bio-modification of RAP samples did not significantly alter fluorescence behavior or its temporal evolution. Beyond binder-scale investigations, the approach is applicable to mastic and asphalt samples, providing a practical pathway for in-situ analysis of binder ageing and for assessing the influence of material composition on photo-oxidative stability.
This study evaluates the quality and durability of asphalt–aggregate adhesive systems in mixtures with high Reclaimed Asphalt Pavement (RAP) mixtures. The work focused on how moisture affects the mechanical and interfacial behaviour of these systems when different rejuvenated binders and aggregates are combined. Four binders (virgin, a blend of RAP-aged and virgin, and two rejuvenated blends with palm-oil-based agents) and two aggregates (serpentinite and quartzite) were assessed. Adhesion quality was measured through the maximum tensile load (Fₘₐₓ), fracture energy (Wf), and adhesive failure area (A
The aging of asphalt materials in the plant and during their service life modifies their chemical composition and properties due to mechanisms such as oxidation, volatilization, polymerization, and photo-oxidation. Since the extraction and recovery of binder from the asphalt mixture is challenging due to process uncertainties, many studies utilize laboratory aging, which can underestimate the results of the different mechanisms. Therefore, this article evaluates the rheological and performance properties of binders aged in the laboratory and recovered from RAP (Reclaimed Asphalt Pavement). Specifically, it seeks to compare the mechanisms and degree of aging on properties measured at high and intermediate temperatures, and their potential impact on the dosage of rejuvenating agents, identifying the parameters most sensitive to oxidation. The data showed that laboratory aging of binders can underestimate the effects on material properties, especially when compared to field mechanisms, which can result in incorrect dosage of the rejuvenating agent. Thus, the most assertive parameters for differentiating materials in relation to aging included RAIPD, RAIFAT, RAITOT, ωc, GRP, Tδ = 45°, true IPG, and the Nf obtained in the LAS test. These parameters provide the appropriate indices for the dosage of rejuvenating agents, in addition to highlighting the importance of the 2s2p1d model for measuring and obtaining rheological parameters.
