Search Results (27)

The urban heat island (UHI) effect poses significant challenges to cities worldwide, particularly in regions like Thessaloniki, Greece, where rising temperatures exacerbate urban living conditions. This study investigates the effectiveness of sustainable urban planning strategies in mitigating the UHI effect by analyzing the spatial distribution of Land Surface Temperature (LST) during the summer heatwave of 2023. Utilizing LANDSAT 8–9 satellite imagery processed with QGIS, we calculated LST, Normalized Difference Vegetation Index (NDVI), and Normalized Difference Built-up Index (NDBI). Additionally, urban structure data from OpenStreetMap (OSM) was integrated to assess the urban fabric. Our findings reveal significant spatial temperature variations, with densely built-up areas, such as the old town and industrial district, exhibiting higher LSTs compared to greener spaces. Based on these results, we propose targeted interventions, including the large-scale implementation of green roofs and the use of light-colored asphalts, which have shown potential for substantial LST reduction. This work underscores the importance of integrating these strategies into a standardized urban planning framework to enhance urban resilience, providing a model that can be applied to other European cities facing similar climate challenges. Full article

In the context of global climate change and rapid urbanization, the Urban Heat Island (UHI) effect has become a pressing environmental and public health concern, particularly in semiarid regions. This study evaluates the microclimatic performance of various urban design strategies aimed at enhancing thermal comfort along a densely built-up street in Van, a medium-sized city located in Turkey’s semiarid climate zone. Using ENVI-met 5.7.2, nine alternative scenarios were simulated, incorporating different configurations of vegetation cover (0%, 25%, 50%, 75%), ground surface materials, and green roof applications (0%, 25%, 50%, 75%). Physiological Equivalent Temperature (PET) and other thermal comfort indicators were assessed at multiple time intervals on the hottest summer day. Results indicate that increasing vegetation cover substantially reduces PET values, with a maximum reduction of 3.0 °C observed in the 75% vegetation scenario. While the scenario with no vegetation but light-colored pavements achieved a 1.8 °C reduction in air temperature at 2:00 p.m., the maximum PET value remained unchanged. Conversely, using dark-colored asphalt decreased the average air temperature by 1 °C and improved the thermal comfort level by reducing the PET by 0.4 °C compared to a non-vegetated scenario. The scenario with the highest overall greenery led to a 2.9 °C drop in air temperature and a 12.8 °C reduction in average PET at 2:00 p.m. compared to other scenarios. The study provides evidence-based recommendations for human-centered urban planning and advocates for the integration of microclimate simulation tools in the early stages of urban development. Full article

Volcanic fermentation is an innovative technique in post-harvest coffee processing that involves forming conical mounds, called “volcanoes”, to create specific biotransformation conditions. This study investigates the impact of different volcano fermentation methods on the chemical composition and sensory attributes of coffee. Four methods were evaluated: asphalt patio (E1), on pallets (E2), in steel containers under the sun (E3), and in steel containers in the shade (E4). The chemical composition was analyzed in terms of sugars (sucrose, glucose, fructose), organic acids (citric, malic, succinic, lactic, acetic) and alcohols (glycerol, ethanol). In addition, color differences (ΔE) and sensory analysis of the fermented coffees were evaluated. The results of this study reveal that volcanic fermentation produces high-quality specialty coffees, but with divergent profiles of acids and alcohols, thus influencing the sensory characteristics of the resulting beverage. However, the different methods of volcanic fermentation did not significantly affect pH and soluble solids, indicating that the microbiota developed an efficient and consistent fermentation regardless of the solar exposure conditions. The most frequently mentioned sensory descriptors were chocolate, citrus fruits, honey/molasses, caramel, floral, and brown sugar. These findings highlight the significant influence of the volcanic fermentation method on the chemical and sensory quality of coffee fermented. Full article

The waterborne epoxy resin (WER) colored antiskid thin layer has been widely used in asphalt pavement to improve driving safety. The tectonic depth determines the antiskid performance of aparticle antiskid type thin layer. The spalling of aggregate from a thin layer may reduce the tectonic depth, thus damaging antiskid performance. The spreading process of aggregate on the WER binder surface plays an important role in the spalling behavior of the thin layer. Herein, the influence of spreading processes on the ceramic aggregate spalling behavior on the WER thin layer was investigated based on laboratory experiments. The abrasion and British Pendulum Number (BPN) tests were employed to evaluate the antispalling and antiskid properties of the WER thin layers with different amounts of WER mortar, coverage rates of first-spread aggregate, and spreading orders of coarse/fine aggregates. Moreover, the tectonic depths of the layers before/after the spalling test were also investigated. The results indicated that the optimal dosage of WER mortar is 2.8 kg/m². The WER thin layer exhibited better anti-striping property when coarse ceramic aggregate was spread first. The first-spread coverage rate of the aggregate on the WER surface is 70%. The thin layer exhibited a superior antispalling performance according to the resulting scheme, with a spalling rate of 3.77%. The tectonic depth only decreased from 1.87 to 1.80 mm after the spalling test. Full article

This paper investigates the potential use of coked sands, a byproduct of the thermal processing (pyrolysis) of oil sands, in asphalt concrete mixtures. After pyrolysis extracts the oil from the oil sand, the remaining mineral part becomes coked and changes color to black as solid waste, resulting in a coating of biochar. The coked sand’s X-ray phase analysis (XRD) shows peaks at 4.2564, 3.6749, 3.3768, 3.2380, 3.1903, 2.4581, 2.2800, and 2.2365. Quartz, aluminosilicates, metal oxides, and possibly even carbonates make up the sand’s mineral makeup, as indicated by these peaks. One way to use them is in road construction. In this study, we substituted sand screenings with coked sand in amounts of 5%, 7%, and 10% to examine its impact on the composition of asphalt concrete. This study used 5% paving bitumen (BND 70/100) as a binder for asphalt mineral materials of varying sizes. It concludes that using coked sand to produce asphalt concrete can save 5–10% of sand screenings. The test results showed that adding 5% and 7% of coked sand increases the compressive strength at 50 °C by 8% and 31%, respectively. Adding 10% of coked sand does not increase the strength and actually makes it weaker. The results of the asphalt concrete samples meet type B grade 1 standards of ST RK 1225-2019. Full article

This study systematically investigated the formulation optimization, performance evaluation, and practical application of epoxy-based composite materials for colored asphalt pavement. By conducting comprehensive experiments, we optimized the composition of epoxy-based composites, verifying their excellent bonding performance, good heat resistance, and UV aging resistance under various temperature conditions. The key optimized component ratios were determined as a 1:1 blend of Type I and Type II epoxy resins, 30 phr of curing agent, 10 phr of toughening agent, 5 phr of diluent, 10% filler, 12% flame retardant, and 10% pigment. At the recommended dosage of 2.0 kg/m² of epoxy binder, the composite structure exhibited the best reinforcement effect, improving low-temperature performance significantly. Compared to ordinary asphalt mixtures, the colored pavement composite structure showed superior mechanical strength, deformation capacity, high-temperature stability (dynamic stability approximately three times higher), and water stability (TSR values up to 95.5%). Furthermore, its fatigue life decay rate was significantly lower, with fatigue limit loading frequencies more than three times those of ordinary asphalt mixtures, demonstrating excellent fatigue resistance. This study provides strong technical support and a theoretical basis for the development and practical application of colored asphalt pavement. Full article

Climate change significantly impacts transportation infrastructure, particularly asphalt pavements. Similarly, the heat absorption of paved surfaces, especially conventional black pavements, significantly intensifies the urban microclimate. Paved surfaces, including asphalt pavements, account for over 30% of the covered surfaces and are vulnerable to rising temperatures, which cause not only pavement distress, such as rutting and cracking, but also urban heat islands (UHI). Sustainable pavement solutions, specifically colored pavements, have been investigated for their potential to mitigate these effects. This review presents an extensive overview of current pavement technologies, emphasizing conventional asphalt’s economic, environmental, and functional characteristics. A discussion of the benefits and challenges of colored pavements is also provided, including their ability to reduce UHI, enhance safety, and contribute to sustainable urban growth. This paper discusses advancements in pavement material science, the use of recycled materials, and the application of reflective coatings, providing insights into sustainable infrastructure development. Transitioning from conventional black pavements to sustainable colored alternatives is not merely a matter of material choice but a strategic transition toward resilient urban planning. Increasing demand for environmentally friendly infrastructure could prompt the construction industry to adopt colored pavements as a tool to promote environmental stewardship. Full article

Colored asphalt pavements have been implemented in South Korea to enhance visibility and lane distinction; however, color fading, accelerated deterioration, and increased pothole occurrence have been noticed. As a solution, alternative materials that can be used for the construction of colored asphalt pavements are being explored. This study evaluates the feasibility of using mudstone aggregate in constructing colored asphalt pavement in South Korea. Initially, aggregate quality tests were conducted on mudstone samples to assess their suitability compared to standard criteria. To enhance the visibility and color retention of colored asphalt, addition of pigment in the colored asphalt pavement mixture was considered and evaluated. The asphalt mixtures were evaluated for deformation, crack and viscoelastic properties using the Kim test, indirect tensile (IDT) strength test, and dynamic modulus test, respectively. Results showed that mudstone aggregate exceeded quality standards and the colored asphalt mixtures demonstrated superior deformation strength and crack resistance compared to typical SMA. However, the addition of pigment slightly reduced these properties. Overall, the findings suggest mudstone aggregate as a viable alternative for constructing colored asphalt pavements, offering potential improvements in durability and color retention. Full article

The increased frequency of extreme hot weather events in recent years poses a significant threat to the lives and health of urban residents. Consequently, the thermal comfort of urban open areas has garnered growing attention. The ground material in these urban open areas directly impacts the thermal environment, which significantly influences the comfort of crowds. This study aimed to assess the effect of land cover materials in urban center squares on the thermal comfort of people in high-temperature conditions. Eight types of land cover materials were selected from the two urban squares in the central district of Nanjing Xinjiekou. Physiological equivalent temperature (PET) calculations were performed by measuring the surface temperature, the air temperature, the humidity, and other relevant data to evaluate population thermal comfort. The findings indicated that grass provided the highest thermal comfort, with PET scores ranked as follows, from low to high: grass, permeable bricks, granite, concrete, basalt, bluestone, andesite, and asphalt. Additionally, factors such as color, roughness, and shade within the same material also impacted thermal comfort. Subsequently, using the ENVI-met 5.1 software, surface materials exhibiting superior thermal comfort were simulated for replacement, aiming to confirm the experimental results and propose retrofit strategies for improving urban square thermal comfort by optimizing material selection. The outcomes of this study hold significant implications for urban open space design and the overall well-being of city dwellers. The thermal environment in urban centers during high-temperature conditions can be improved by optimizing the choice of land cover materials in urban open areas, thereby enhancing the comfort of the population. Full article

Similar to the asphalt mixture, the polyurethane (PU) mixture’s performance and characteristics are dependent on many variables. In this study, six variables, including aggregate gradation (limestone and basalt), aggregate type, PU type, PU content, and curing condition, and several parameter analyzing methods were chosen to determine the effect of variables on the dynamic property, rheological property, and rutting resistance of the PU mixture. The limestone aggregate gradation exhibited a substantial effect on the dynamic property, rheological property, and rutting resistance of the PU mixture; the basalt aggregate gradation exhibited significant influence on the dynamic property and rutting resistance, but a moderate effect on the rheological property. The aggregate type could influence the rheological property and rutting resistance. The slow curing speed of the PU binder decreased the dynamic modulus and rutting resistance but did not influence the phase angle. The rise in PU binder content would only improve the PU mixture’s resistance to rutting. The curing condition and color additive had no impact on the PU mixture’s properties. The generalized logistic sigmoidal (GLS) and Christensen Anderson and Marasteanu model (CAM) models could precisely predict the dynamic modulus and phase angle respectively disregarding the PU mixture features. PUM-10/B exhibited the greatest rutting resistance. The findings will aid in comprehending the properties and influencing factors of the PU mixture as well as in designing the desired mixture. Full article

Urbanization increases the urban land surface temperature (LST), challenging society and the environment. This study measured the LST of diverse land uses (LU) in Dallas–Fort Worth (DFW) using a high-resolution (8 cm) thermal infrared sensor onboard a small, unmanned aerial vehicle (UAV). LUs included park (PA), industrial (IA), residential low-cost (RLC), and residential high-cost (RHC) areas. LST was collected by the UAV at different times on eight nonconsecutive days. UAV-collected LST was compared with that from Landsat 8-9 and in situ measurements. RHC reported the highest mean LST, and PA showed the lowest mean LST. Dark-colored asphalt shingle roofs in RHC had the highest mean LST range at 35.67 °C. Lower LST was measured in shaded areas and under thick green cover, whereas areas with thin green cover occasionally reported higher LST than pavements. The micro-urban heat island (MUHI) was calculated between LUs and within land cover types (roof, pavement, green, and water). The MUHI varied from 4.83 °C to 15.85 °C between LUs and 0.2 °C to 23.5 °C within LUs for the less than 1 km² study area. While the UAV thermal sensor and Landsat demonstrated a similar trend of LST variation, the UAV sensor reported more intense MUHI. An average percent bias (PBIAS) of 5.1% was calculated between the UAV sensor and in situ measurements. This study helps inform the urban design process by demonstrating how land use decisions impact LST locally and provides valuable insight for studies concerned with fine-scale urban LST variability. Full article

Despite asphalt self-healing with encapsulated rejuvenators having been intensively researched over the last decade, there is still uncertainty about the performance advantages granted by this technology. As a way of adding to the existing set of research methodologies, this study aimed to test the feasibility of a visual method to investigate the working mechanism of encapsulated rejuvenators in the bituminous mixture. For this purpose, clear bituminous mixtures were produced using a colorless synthetic binder and a pigment was added to the rejuvenator incorporated in the calcium alginate capsules. The internal structure of the bituminous mixtures containing these capsules was inspected both on loaded and unloaded specimens. The colored rejuvenator was also directly added to cracked specimens and its distribution was studied, along with the interaction between the rejuvenator and the synthetic binder. The results show that the rejuvenator could modify the binder to a limited extent, and the bituminous mixtures containing capsules showed evidence of rejuvenator release. It is demonstrated that the aggregate gradation of mixtures has a significant effect on capsule damage and rejuvenator release. However, the pigment can be filtrated from the rejuvenator by the capsule polymer structure and the asphalt. Even though the methodology presented some constraints, it has been proven to be capable of achieving the initial goal, while also acting as an important first step in the visual study of rejuvenator release in asphalt. Full article

A key factor for safe and comfortable driving on roads are properly reflective and well visible pavement surfaces at night. The brightness of the road pavement surface depends on the amount of light falling on it and the reflection properties of the road pavement surface at any point. The luminance of the pavement depends on its physical condition, age and type of pavement, direction of illumination, and observation conditions. Different pavements can have different reflection characteristics that depend on the surface texture, materials, and binder (type and quantity). Experimental research was carried out on the carriageways and bicycle paths of Vilnius city streets, which differ in color and age. The analysis of the research results showed differences between the surface reflectance characteristics of these pavements depending on the color of the pavement, surface conditions, and age. The reflection properties of red asphalt pavements are better than black ones when the pavement surface is wet or moist. The reduced luminance coefficients of the carriageway (asphalt pavement installed in 2021) are about 12% lower than those of the carriageway pavement installed 10 years ago and about 60% lower for wet and moist pavements. The results obtained from the research are significant for street designers when choosing the type of pavement and designing street lighting. Full article

The conversion of polymer waste, food waste, and biomasses through thermochemical decomposition to fuels, syngas, and solid phase, named char/biochar particles, gives a second life to these waste materials, and this process has been widely investigated in the last two decades. The main thermochemical decomposition processes that have been explored are slow, fast, and flash pyrolysis, torrefaction, gasification, and hydrothermal liquefaction, which produce char/biochar particles that differ in their chemical and physical properties, i.e., their carbon-content, CHNOS compositions, porosity, and adsorption ability. Currently, the main proposed applications of the char/biochar particles are in the agricultural sector as fertilizers for soil retirement and water treatment, as well as use as high adsorption particles. Therefore, according to recently published papers, char/biochar particles could be successfully considered for the formulation of sustainable polymer and biopolymer-based composites. Additionally, in the last decade, these particles have also been proposed as suitable fillers for asphalts. Based on these findings, the current review gives a critical overview that highlights the advantages in using these novel particles as suitable additives and fillers, and at the same time, it shows some drawbacks in their use. Adding char/biochar particles in polymers and biopolymers significantly increases their elastic modulus, tensile strength, and flame and oxygen resistance, although composite ductility is significantly penalized. Unfortunately, due to the dark color of the char/biochar particles, all composites show brown-black coloration, and this issue limits the applications. Full article

The article presents the application of a hyperspectral camera in mobile robot navigation. Hyperspectral cameras are imaging systems that can capture a wide range of electromagnetic spectra. This feature allows them to detect a broader range of colors and features than traditional cameras and to perceive the environment more accurately. Several surface types, such as mud, can be challenging to detect using an RGB camera. In our system, the hyperspectral camera is used for ground recognition (e.g., grass, bumpy road, asphalt). Traditional global path planning methods take the shortest path length as the optimization objective. We propose an improved A* algorithm to generate the collision-free path. Semantic information makes it possible to plan a feasible and safe path in a complex off-road environment, taking traveling time as the optimization objective. We presented the results of the experiments for data collected in a natural environment. An important novelty of this paper is using a modified nearest neighbor method for hyperspectral data analysis and then using the data for path planning tasks in the same work. Using the nearest neighbor method allows us to adjust the robotic system much faster than using neural networks. As our system is continuously evolving, we intend to examine the performance of the vehicle on various road surfaces, which is why we sought to create a classification system that does not require a prolonged learning process. In our paper, we aimed to demonstrate that the incorporation of a hyperspectral camera can not only enhance route planning but also aid in the determination of parameters such as speed and acceleration. Full article