ABSTRACT
Due to the COVID-19 pandemic, global personal protective equipment (PPE) volume production and demand increased by 300-400% between 2019 and 2021. In this scenario, the present study aims to propose and validate an innovative circular economy scenario for end of life (EoL) PPEs, reusing them to produce reinforced bituminous mixtures. Despite that several studies confirmed the possibility of reusing plastic in the asphalt mixtures, none of them investigated the potential of PPEs, highlighting the innovativeness in the scientific panorama. Five different alternatives of EoL PPE mixtures (different products, materials, dosages, etc.) were tested at laboratory scale to verify the technical feasibility of the proposed scenario. The most promising solution resulted to be the mix of gloves and face masks composed by polypropylene, polyethylene, nitrile and lattice at a dosage of 0,5% weight/weight that allowed to produce bituminous mixtures with acceptable performances in terms of relevant mechanical parameters while recycling waste PPEs. This leads to environmental benefits, since more than 3kg of EoL PPEs per square meter of road pavement can be reused instead of disposed (about 1,5 million tons/year considering the bituminous mixtures produced at European level), as well as economic benefits for public administrations and the collectivity, due to the reduced landfilling of solid wastes.
ABSTRACT
With the outbreak of the coronavirus (COVID-19) and the spread of this virus, the use of medical equipment, like 3-layerface masks, has increased dramatically. The proliferation of polymer-based face masks has become an environmental problem as ittakes years to completely decompose. The lack of proper management and collection causes environmental pollution. Therefore,considering the polymer base of the face masks and with the aim of improving the asphalt mixtures, in this article, the face mask andits different layers are added to the asphalt mixtures in 4 different weight percentages and in two different sizes, and Marshall test,Resilient modulus, Indirect tensile, Moisture damage, Rutting and Fatigue test were performed on the samples. The experimentalresults show that the addition of these materials to the asphalt mixtures improves the performance of asphalt and 12mm long fibersyielded better results than the results of 8mm long fibers.
ABSTRACT
The outbreak of the COVID-19 pandemic has stimulated the demand for disposable masks to an unprecedented level, which also poses a significant risk to the natural environment from the improper treatment or disposal of waste masks. To lower such an environmental risk and maximize the added value of the waste masks, this paper proposed to recycle the waste mask fiber (MF) in combination with the waste cooking oil (WCO) for hot mix asphalt (HMA) application. A series of MF + WCO modified asphalt binders were first designed and fabricated. Their performance properties were then systematically measured. The physical-rheological test results showed that the incorporation of MF can significantly improve the high-temperature rutting resistance performance of asphalt binder. However, it may also lower the asphalt's low-temperature anti-cracking performance. The addition of WCO was found to compensate for this low-temperature performance loss effectively, and the MF5% + WCO3% was identified as the best combination. The Fourier transform infrared (FTIR) spectroscopy test results revealed that the asphalt modified by the MF + WCO involved only a physical modification. The performance test results indicated that the high-temperature permanent deformation resistance and low-temperature anti-cracking of MF5% + WCO3% modified HMA was greatly enhanced, while its moisture stability was slightly reduced but still met the specification requirement. The environmental benefit assessments proved that recycling the waste masks for asphalt paving can provide an enormous added value to pavement engineering in terms of carbon emission reduction and land resource saving.
ABSTRACT
The growth of logistic cities and freight villages to meet the increasing demand of e-commerce is unstoppable. This strategic sector has boomed during the COVID-19 pandemic, and it is estimated that by 2025, 138 million sqm of additional e-commerce areas will be built worldwide. Only in the last decade, the European logistic construction activity has tripled. Endless cities of asphalt and concrete have been built to host e-commerce companies, posing severe environmental threats such as desertification, loss of ecosystem and wildlife. Seeking to resolve these challenges, the United Nations Industrial Development Organization has proposed an international framework for Eco-Industrial Parks, with environmental guidelines for rainwater management, biodiversity preservation, or creation of recreational areas amongst others. However, prior studies and recommendations focused on the formulation of resilient spatial planning solutions for industrial logistic areas are yet very limited, and comprehensive literature reviews are still lacking. Aiming to address this research gap, this paper includes a review of recent investigations and projects focused on the study of resilient solutions for the design of industrial logistic areas. A bibliometric analysis of the literature published in Scopus database from 1992 to 2022 concerning terms such as Industrial Park, Eco-Industrial Park, or Nature-based Solutions is presented. The results reveal that the connection between Industrial Logistic Parks and Nature-based Solutions is very weak, or almost non-existent. This paper also discusses the project Plataforma Central Iberum-one of the largest industrial logistic spaces (3.5 million sqm) built in Spain- as a case study. This project is one of the first Industrial Logistic Parks developed in this country where nature-based solutions such as the integration of rainwater wetlands, load-bearing permeable pavements, green v-ditch medians, and natural self-sustaining infrastructure parks with diverse native plant species, were implemented. Overall, this paper aims to highlight the urgency to discuss and adopt Nature-based Solutions to render Industrial Logistic Parks more resilient.
ABSTRACT
Natural aggregates are being depleted due to the high demand for road and building construction and need to be replaced with alternative materials. This study investigated the potential of using Palm kernel shells (PaKS) as a partial replacement for natural aggregates (NA) and waste plastics (WP) as a binder. The physical and volumetric properties of the different asphaltic mixes (AM) were assessed using the Marshall Method. The bitumen content of the mix design samples was varied from 4.0% to 7.5% of the total weight of aggregates utilized. According to the Marshall parameters, at 5.5% bitumen content, the maximum Marshall Stability value of the different mix designs increased from 9.8 kN to 12.1 kN and the flow value increased from 3.0 mm to 3.7 mm. The experimental results based on the optimum bitumen content determined by the Marshall method demonstrate that PaKS and WP can be utilized to modify AM. However, additional tests will be needed to evaluate the use of this composition in road construction.
ABSTRACT
In the context of the global pandemic of COVID-19, the use and disposal of medical masks have created a series of ethical and environmental issues. The purpose of this paper is to study and evaluate the high temperature properties and thermal storage stability of discarded-mask (DM)-modified asphalt from a multi-scale perspective using molecular dynamics (MD) simulation and experimental methods. A series of tests was conducted to evaluate the physical, rheological, thermal storage stability and microscopic properties of the samples. These tests include softening point, rotational viscosity, dynamic shear rheology (DSR), Fourier transform infrared (FT-IR) spectroscopy and molecular dynamics simulation. The results showed that the DM modifier could improve the softening point, rotational viscosity and rutting factor of the asphalt. After thermal storage, the DM-modified asphalt produced segregation. The difference in the softening point between the top and bottom of the sample increased from 2.2 °C to 17.1 °C when the DM modifier admixture was increased from 1% to 4%. FT-IR test results showed that the main component of the DM modifier was polypropylene, and the DM-modified asphalt was mainly a physical co-blending process. MD simulation results show that the DM modifier can increase the cohesive energy density (CED) and reduce the fractional free volume (FFV) of asphalt and reduce the binding energy between base asphalt and DM modifier. Multi-scale characterization reveals that DM modifiers can improve the high temperature performance and reduce the thermal storage stability of asphalt. It is noteworthy that both macroscopic tests and microscopic simulations show that 1% is an acceptable dosage level.
ABSTRACT
Human activities significantly contribution to the yearly generated plastic wastes. Moreover, the enormous increase in face masks and face shields caused by the emergence of the COVID-19 pandemic has doubled the generated plastic wastes. Although there is an added benefit of using plastic waste in construction, the cost associated with their application, specifically the face mask, has not been addressed. This paper presents a simplified and rapid estimation of the cost associated with the collection, processing, and application of face masks in hot-mix asphalt (HMA) pavements. Two scenarios, mask modified asphalt pavement and conventional asphalt pavement, are considered. The total cost is based on market price and prices from waste management facilities and plastic processing companies. Life Cycle Cost Analysis (LCCA) is used to evaluate the long-term costs of mask modified asphalt pavement and conventional asphalt pavement. Results show that no significant difference in initial total cost between the two scenarios for pavement sections with lengths less than 500m and the number of lanes less than 6. The difference in total cost begins with lengths greater than 500 m for 5 and 6 Lanes. Despite the higher initial costs for the mask modified asphalt pavement, the LCCA shows that there is a 29% maintenance cost reduction over the 40 years life cycle of the asphalt pavement. The use of LCCA shows the benefit of the selection of the most cost-effective strategy and how the use of mask modified asphalt pavement over the conventional asphalt pavement can save money over the life cycle of the asphalt and improve rutting and stiffens.
ABSTRACT
Asphalt pavement, as an important engineering structure under various conditions such as freeze–thaw cycles and temperature fluctuations, suffers from failures such as low-temperature cracks (LTCs) and intermediate-temperature cracks (ITCs). Therefore, studying and providing a suitable solution is a concern of researchers in this field. On the other hand, the amount of hospital waste is increasing due to the Covid-19 pandemic;hence, one of the appropriate solutions is to recycle and use them in engineering structures such as asphalt pavement to reduce environmental pollution. In this study, a hospital waste pyrolytic carbon black (HWPCB) additive from recycled hospital waste resulting from the COVID-19 pandemic was used to improve the LTCs and ITCs resistance of Warm Mix Asphalt (WMA). For this purpose, three geometries called Symmetric specimen SCB (containing vertical cracks), Classical-Modified specimen SCB-1 (containing angular cracks), and Symmetric specimen ENDB (containing vertical cracks) were subjected to mode I loading conditions. In order to adapt the actual conditions of the pavement to the laboratory conditions, the samples were subjected to 0 and 3 cycles of freeze–thaw damage (FTD). They were fractured at 15°Celsius. The results showed that adding 18 % HWPCB to the WMA mixture increased the fracture energy and fracture toughness of all three geometries under mode I in both 0 and 3 FTD cycles at ± 15 °C. Also, it was concluded that the HWPCB additive was able to compensate for the reduction in resistance created by the 3 FTD cycles and increase it to some extent. On the other hand, the results of the Tensile Stiffness Index (TSI) and Tensile Strength (TS) indices showed that adding 9 and 18 % HWPCB increased the resistance to elastic deformation at ± 15 °C (under 0 and 3 FTD cycles) in addition to improving the crack resistance of the WMA mixture. The results of the Flexibility Index (FI), Toughness Index (TI), and Cracking Resistance Index (CRI) brittleness indices for WMA mixtures containing different percentages of HWPCB additive showed that this additive slightly reduced the flexibility of the mixture under 0 and 3 FTD cycles at temperatures of ± 15 °C. Finally, it was concluded that using HWPCB additive in the WMA mixture improved the behavior of LTC and ITC under mode I and FTD conditions.
ABSTRACT
Waste management has been recognized as a real issue in the current situation due to the COVID-19 impact on people’s lifestyles. Therefore, serious actions need to be taken to control and manage this impact on the environment. One of these important environmental programs is the investigation and research of generated wastes during the pandemic. Due to the COVID-19 pandemic, the types and amounts of waste generation have changed, therefore a way forward to reduce this impact is to investigate the data that coming from landfill to devise an appropriate approach. The goal of this study is to predict the amount of construction and demolition (C&D), Grit, Asphalt waste, and Treated Biomedical waste (TBW) before, during, and after pandemic using grey systems theory. The grey model is a relatively new forecasting method that has been employed for prediction in a small amount of data and is also used for uncertain systems. In this study, the data coming from Regina landfill is used to predict the amount of wastes generated during the pandemic using the grey model. The results will be compared with the existing regression-based waste model. Different measures like mean absolute percent error (MAPE) and root mean square error (RMSE) will be used to compare and evaluate the performance of these models. Finally, the best forecasting model will be chosen to predict the amount of waste generation for the future generation. © 2023, Canadian Society for Civil Engineering.
ABSTRACT
Sound and effective solid waste management practices are important to mitigate health risks and protect the surrounding environment. Proper Municipal Solid Waste (MSW) management practices are especially important during the COVID pandemic. Since the beginning of the COVID pandemic different waste disposal and recycling behaviors are observed in Regina, the capital city of Saskatchewan. It is believed the changes of waste disposal rate at Regina landfill is related to the new hygienic guidelines, more opportunities for work from home, distinct consumer behaviors, and COVID related regulations and recommendations. Waste generation and recycling behaviors are complex and multi-dimensional. The objective of this study is to model waste disposal rate at the City of Regina landfill using a System Dynamics (SD) model. The proposed SD model will help us better manage the City of Regina’s human resources during the pandemic and estimate the demand of additional personal protective equipment required for the waste management workers. In the present work, a total of 7.5 years of waste disposal data is collected, consolidated, and verified. Socio-economical parameters such as GDPs and population at Regina were also collected during the study period from 2013 to 2020. The model is built using stock-flow diagram to illustrate the effects of various inter-related variables on the waste generation behaviors. Construction and demolition (C&D), Grit, Asphalt Shingles Only, Asphalt Shingles Mixed and Treated Biomedical wastes data are used in the SD model. Results show that waste generation has affected by the pandemic and there is a general increase in amount of waste generation. The modeling results are important because it helps us predict the amount of MSW during and after the pandemic. © 2023, Canadian Society for Civil Engineering.
ABSTRACT
The hazards of plastic waste (PW) from polymers (e.g., polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride (PVC), nylon, polystyrene (PS), etc.), the mechanism of its spread in general, and its ubiquity in our daily lives as a continuously and/or frequently expelled product are a crisis of the twenty-first century, as reported by the United Nations in 2019, especially after the outbreak of the COVID-19 pandemic. This research included the process of modifying the rheological properties of asphalt to obtain asphalt suitable for use in a high-humidity atmosphere. The Iraqi climate is characterized by heat that reaches the point of harshness in the summer and coldness that falls below zero on some winter days. From this point of view, our recent study focuses mainly on making rheological and chemical modifications to asphalt using spent polymeric materials and used lubricating oils (ULO), thus achieving two important goals, namely obtaining asphalt with rheological properties resistant to the Iraqi atmosphere as well as eliminating both solid and liquid environmental pollutants. The microstructure and morphology of the designed patches were characterized using scanning electron microscopy (SEM) to indicate phase composition.
ABSTRACT
Today, the world faces an enormous increase in plastic waste pollution caused by the emergence of the COVID-19 pandemic. Plastic pollution has been already one of the greatest threats to our planet before the Coronavirus outbreak. The disposal of millions of personal protective equipment (PPE) in the form of face masks has significantly contributed to the generation of plastic waste and has exacerbated plastic pollution. In an attempt to mitigate pollution caused by the excess PPE waste, an innovative way was developed in this research to reduce pandemic-generated wastes by using the shredded face mask (SFM) fibers as an additive to hot mix asphalt (HMA) to enhance rutting resistance. Rutting or permanent deformation is one of the major distresses of asphalt pavement. Since the SFM behaves as a semi-liquid between 115.5 and 160 °C, which is in the range of HMA mixing and paving temperature, it can function as a binding agent to glue the aggregates. When the pavement is cooled down to ambient temperature, the hardened SFM can provide stability and stiffness to HMA. Based on the results of this study, the modified mixes exhibited excellent resistance to permanent deformation under the Asphalt Pavement Analyzer (APA), as rutting depth values were reduced from 3.0 mm to 0.93 mm by increasing the SFM content from 0% to 1.5%. From the rutting test results and premature distress mechanism study, the appropriate addition of SFM modifiers could improve the high-temperature properties of HMA that can be used to strengthen high-compression and shearing zones in the pavement structure.
Subject(s)
COVID-19 , Masks , COVID-19/prevention & control , Humans , Hydrocarbons , Pandemics/prevention & control , PlasticsABSTRACT
In order to meet the environmental needs caused by large plastic waste accumulation, in the road construction sector, an effort is being made to integrate plastic waste with the function of polymer into asphalt mixtures;with the purpose of improving the mechanical performance of the pavement layers. This study focuses on the effect of a recycled mixture of plastic waste on the chemical, thermal, and rheological properties of designed asphalt blends and on the identification of the most suitable composition blend to be proposed for making asphalt mixture through a dry modification method. Thermo-gravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis were carried out to investigate the effect of various concentrations and dimensions of plastic waste (PW) on the neat binder (NB). The frequency sweep test and the multiple stress creep and recovery test were performed to analyze the viscoelastic behavior of the asphalt blends made up of PW in comparison with NB and a commercial modified bitumen (MB). It has been observed that the presence of various types of plastic materials having different melting temperatures does not allow a total melting of PW powder at the mixing temperatures. However, the addition of PW in the asphalt blend significantly improved the aging resistance without affecting the oxidation process of the plastic compound present in the asphalt blend. Furthermore, when the asphalt blend mixed with 20% PW by the weight of bitumen is adopted into the asphalt mixture as polymer, it improves the elasticity and strengthens the mixture better than the mixture containing MB.
ABSTRACT
This Special Issue "Sustainable Designed Pavement Materials" has been proposed and organized as a means to present recent developments in the field of environmentally-friendly designed pavement materials. For this reason, articles included in this special issue relate to different aspects of pavement materials, from industry solid waste recycling to pavement materials recycling, from pavement materials modification to asphalt performance characterization, from pavement defect detection to pavement maintenance, and from asphalt pavement to cement concrete pavement, as highlighted in this editorial.