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16 pages, 6540 KiB

Open AccessArticle

Evaluation of Interface Shear Strength Coefficient of Alternative Geogrid Made from Para Rubber Sheet

by Anubud Liangsunthonsit, Pakkapon Jaroonrat, Jiratchaya Ayawanna, Weerawut Naebpetch and Salisa Chaiyaput

Polymers 2023, 15(7), 1707; https://doi.org/10.3390/polym15071707 - 29 Mar 2023

Cited by 3 | Viewed by 2260

Abstract

In this work, elastic natural rubber compound sheet (RCS) and ribbed smoked sheet grade 3 (RSS) were studied as alternative replacements for polymer geogrid for soil reinforcement. In order to investigate the reinforcing effectiveness in three distinct environments using the interface shear strength [...] Read more.

In this work, elastic natural rubber compound sheet (RCS) and ribbed smoked sheet grade 3 (RSS) were studied as alternative replacements for polymer geogrid for soil reinforcement. In order to investigate the reinforcing effectiveness in three distinct environments using the interface shear strength coefficient (R_in) by the large-scale direct shear test, the RSS and RCS geogrids were installed independently in sand, lateritic soil, and clay. Using either an RSS geogrid or RCS geogrid, the average R_in is progressively smaller in reinforced sand, lateritic soil, and clay, respectively. Higher tensile strength of reinforced materials using the RCS geogrid than those using the RSS geogrid is encouraged by the better elastic characteristics of the RCS geogrid. Thus, utilizing the RCS geogrid-reinforced materials can better increase the shear strength of coarse-grained soil such as sand and gravel. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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25 pages, 7308 KiB

Open AccessArticle

Incorporation of the Multi-Layer Plastic Packaging in the Asphalt Binders: Physical, Thermal, Rheological, and Storage Properties Evaluation

by Ali Qabur, Hassan Baaj and Mohab El-Hakim

Polymers 2022, 14(24), 5396; https://doi.org/10.3390/polym14245396 - 9 Dec 2022

Cited by 10 | Viewed by 2073

Abstract

The amount of residual Multi-layer Plastic Packaging (MPP) in Canada has greatly increased in the last two decades, which has economic and environmental consequences. MPP is primarily made up of two or more layers of Polyethylene (PE), Polyester (PET), Nylon (NY), and Metalized [...] Read more.

The amount of residual Multi-layer Plastic Packaging (MPP) in Canada has greatly increased in the last two decades, which has economic and environmental consequences. MPP is primarily made up of two or more layers of Polyethylene (PE), Polyester (PET), Nylon (NY), and Metalized Polyester (METPET). While MPP has not been used as an asphalt modifier, some of the materials commonly found in MPP, such as PE and PET, have also been successfully used as asphalt modifiers. Nevertheless, a few recent studies have demonstrated the potential for reusing MPP as an asphalt modifier to improve asphalt pavement performance. Recycling post-industrial MPP instead of using raw polymers could lead to economic and environmental benefits. However, a comprehensive study to evaluate MPP as a viable asphalt additive is lacking. The main objective of this study is to evaluate the feasibility of using MPP as an asphalt modifier via the wet method, considering the physical, thermal, rheological, and storage properties of the MPP-modified binder at different MPP concentrations (2%, 4%, and 8%) in asphalt cement (PG 58–28). MPP-modified binders were evaluated using the following instruments: Differential Scanning Calorimeter (DSC), Thermogravimetric Analysis (TGA), Superpave Dynamic Shear Rheometer (DSR), Rotational Viscosity (RV), and Environmental Scanning Electron Microscopy (ESEM). Test results indicated that the incorporation of MPP has a strong potential to improve permanent deformation resistance at high temperatures. In addition, MPP shows a moderate impact on fatigue cracking performance at intermediate temperatures. Overall, in low-temperature climates, using less than 4% of MPP additives would offer higher fatigue damage resistance along with adequate permanent deformation. In high-temperature climates, higher concentrations of additives may be preferable to resist permanent deformation. Finally, MPP is a challenge for existing recycling systems, and its incorporation into asphalt applications may develop more sustainable materials that would contribute to circular economy principles. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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17 pages, 4567 KiB

Open AccessArticle

Analysis of Microplastics in Aquatic Shellfish by Pyrolysis–Gas Chromatography/Mass Spectrometry after Alkali Digestion and Solvent Extraction

by Yingying Zhong, Qibei Bao, Lifeng Yuan, Jiawen Liu, Yan Cai and Xianfeng Chen

Polymers 2022, 14(18), 3888; https://doi.org/10.3390/polym14183888 - 17 Sep 2022

Cited by 7 | Viewed by 3648

Abstract

Microplastics are harmful to both marine life and humans. Herein, a pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) technique for the detection of microplastics in aquatic shellfish is demonstrated. The organic matter in aquatic shellfish was removed by alkali digestion. Subsequently, using hexafluoroisopropanol as the extraction [...] Read more.

Microplastics are harmful to both marine life and humans. Herein, a pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) technique for the detection of microplastics in aquatic shellfish is demonstrated. The organic matter in aquatic shellfish was removed by alkali digestion. Subsequently, using hexafluoroisopropanol as the extraction solvent, the extraction method was optimized. The influence of the digestion process on the nature of microplastics was investigated by analyzing the samples before and after the alkali treatment via infrared spectrometry, laser particle sizing, and scanning electron microscopy. Spiked recovery experiments and an analysis of actual samples were performed using PA6 and PA66 as analytes. A quantitative analysis of the characteristic ion fragment produced by high-temperature cracking was performed after chromatographic separation and mass spectrometry identification. The linear range of this method for PA6 and PA66 was 2–64 μg. The limits of detection of PA6 and PA66 were 0.2 and 0.6 μg, while the limits of quantitation were 0.6 and 2.0 μg, respectively. Recovery ranged from 74.4 to 101.62%, with a precision of 4.53–7.56%. The results suggest that the Py-GC/MS technique is suitable for the analysis and detection of trace microplastics in aquatic shellfish. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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27 pages, 7812 KiB

Open AccessArticle

Performance Optimization Approach of Polymer Modified Asphalt Mixtures with PET and PE Wastes: A Safety Study for Utilizing Eco-Friendly Circular Economy-Based SDGs Concepts

by Faizan Mushtaq, Zhian Huang, Syyed Adnan Raheel Shah, Yinghua Zhang, Yukun Gao, Marc Azab, Sajid Hussain and Muhammad Kashif Anwar

Polymers 2022, 14(12), 2493; https://doi.org/10.3390/polym14122493 - 19 Jun 2022

Cited by 5 | Viewed by 3623

Abstract

Eco-friendly waste utilization helps in the development of sustainable infrastructures. Recently, researchers have focused on the production of road infrastructures using the circular economy concept of human safety. The objective of this study is to investigate and explore the utilization of optimum polymer [...] Read more.

Eco-friendly waste utilization helps in the development of sustainable infrastructures. Recently, researchers have focused on the production of road infrastructures using the circular economy concept of human safety. The objective of this study is to investigate and explore the utilization of optimum polymer waste content for the development of polymer-modified asphalt mixtures using response surface methodology (RSM). RSM based on Box–Behnken design (BBD) was employed to optimize experimental design and included three factors: X1, polymer type; X2, polymer contents; and X3, testing day. The optimized responses determined by the RSM were as follows: MS of 42.98 kN, MF of 5.08 mm, and MQ of 8.66 kN/mm, indicating a favorable and consistent precision in comparison with experimental values. Moreover, the Marshall characteristics of samples prepared with PE were quite improved compared to PET. In conclusion, the incorporation of such polymer wastes in road construction is a sustainable and cost-effective way of improving their engineering properties. This study will help in the development of sustainable road infrastructures supporting human safety and environmentally friendly practices. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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18 pages, 3321 KiB

Open AccessArticle

Mechanical Performance of Polymeric ARGF-Based Fly Ash-Concrete Composites: A Study for Eco-Friendly Circular Economy Application

by Hassan Tariq, Rao Muhammad Arsalan Siddique, Syyed Adnan Raheel Shah, Marc Azab, Attiq-Ur-Rehman, Rizwan Qadeer, Muhammad Kaleem Ullah and Fahad Iqbal

Polymers 2022, 14(9), 1774; https://doi.org/10.3390/polym14091774 - 27 Apr 2022

Cited by 17 | Viewed by 2557

Abstract

At present, low tensile mechanical properties and a high carbon footprint are considered the chief drawbacks of plain cement concrete (PCC). At the same time, the combination of supplementary cementitious material (SCM) and reinforcement of fiber filaments is an innovative and eco-friendly approach [...] Read more.

At present, low tensile mechanical properties and a high carbon footprint are considered the chief drawbacks of plain cement concrete (PCC). At the same time, the combination of supplementary cementitious material (SCM) and reinforcement of fiber filaments is an innovative and eco-friendly approach to overcome the tensile and environmental drawbacks of plain cement concrete (PCC). The combined and individual effect of fly ash (FA) and Alkali resistance glass fiber (ARGF) with several contents on the mechanical characteristics of M20 grade plain cement concrete was investigated in this study. A total of 20 concrete mix proportions were prepared with numerous contents of FA (i.e., 0, 10, 20, 30 and 40%) and ARGF (i.e., 0, 0.5, 1 and 1.5%). The curing of these concrete specimens was carried out for 7 and 28 days. For the analysis of concrete mechanical characteristics, the following flexural, split tensile, and compressive strength tests were applied to these casted specimens. The outcomes reveal that the mechanical properties increase with the addition of fibers and decrease at 30 and 40% replacement of cement with fly ash. Replacement of cement at higher percentages (i.e., 30 and 40) negatively affects the mechanical properties of concrete. On the other hand, the addition of fibers positively enhanced the flexural and tensile strength of concrete mixes with and without FA in contrast to compressive strength. In the end, it was concluded that the combined addition of these two materials enhances the strength and toughness of plain cement concrete, supportive of the application of an eco-friendly circular economy. The relationship among the mechanical properties of fiber-reinforced concrete was successfully generated at each percentage of fly ash. The R-square for general relationships varied from (0.48–0.90) to (0.68–0.96) for each percentage of FA fiber reinforced concrete. Additionally, the accumulation of fibers effectively boosts the mechanical properties of all concrete mixes. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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22 pages, 866 KiB

Open AccessArticle

Odor and Constituent Odorants of HDPE–Lignin Blends of Different Lignin Origin

by Bianca Lok, Gunnar Mueller, Johannes Ganster, Jens Erdmann, Andrea Buettner and Philipp Denk

Polymers 2022, 14(1), 206; https://doi.org/10.3390/polym14010206 - 5 Jan 2022

Cited by 6 | Viewed by 3079

Abstract

The still-rising global demand for plastics warrants the substitution of non-renewable mineral oil-based resources with natural products as a decisive step towards sustainability. Lignin is one of the most abundant natural polymers and represents an ideal but hitherto highly underutilized raw material to [...] Read more.

The still-rising global demand for plastics warrants the substitution of non-renewable mineral oil-based resources with natural products as a decisive step towards sustainability. Lignin is one of the most abundant natural polymers and represents an ideal but hitherto highly underutilized raw material to replace petroleum-based resources. In particular, the use of lignin composites, especially polyolefin–lignin blends, is currently on the rise. In addition to specific mechanical property requirements, a challenge of implementing these alternative polymers is their heavy odor load. This is especially relevant for lignin, which exhibits an intrinsic odor that limits its use as an ingredient in blends intended for high quality applications. The present study addressed this issue by undertaking a systematic evaluation of the odor properties and constituent odorants of commercially available lignins and related high-density polyethylene (HDPE) blends. The potent odors of the investigated samples could be attributed to the presence of 71 individual odorous constituents that originated primarily from the structurally complex lignin. The majority of them was assignable to six main substance classes: carboxylic acids, aldehydes, phenols, furan compounds, alkylated 2-cyclopenten-1-ones, and sulfur compounds. The odors were strongly related to both the lignin raw materials and the different processes of their extraction, while the production of the blends had a lower but also significant influence. Especially the investigated soda lignin with hay- and honey-like odors was highly different in its odorant composition compared to lignins resulting from the sulfurous kraft process predominantly characterized by smoky and burnt odors. These observations highlight the importance of sufficient purification of the lignin raw material and the need for odor abatement procedures during the compounding process. The molecular elucidation of the odorants causing the strong odor represents an important procedure to develop odor reduction strategies. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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16 pages, 4537 KiB

Open AccessArticle

Utilization of Radium-Bead Material for Road Safety: An Application of the Circular Economy Concept

by Sajid Hussain, Xuemei Zhou, Syyed Adnan Raheel Shah, Naveed Ahmad, Muhammad Kashif Anwar and Muhammad Aamir Basheer

Polymers 2021, 13(21), 3708; https://doi.org/10.3390/polym13213708 - 27 Oct 2021

Cited by 1 | Viewed by 3754

Abstract

Road safety has become a serious issue in both developed and developing countries, costing billions of dollars every year. Road accidents at nighttime especially in low illumination situations are common and severe and have gained a lot of attention. To improve visibility and [...] Read more.

Road safety has become a serious issue in both developed and developing countries, costing billions of dollars every year. Road accidents at nighttime especially in low illumination situations are common and severe and have gained a lot of attention. To improve visibility and avoid traffic accidents, a series of efforts have been made but the existing mechanism is facing continuous challenges and highlighting a need for smart highways with high efficiency, road safety, and strength. In this study, the use of radium polymer beads (RPB) is proposed to avoid road accidents. The effect of RPB was investigated by comparing the results of the beads’ surface and modified asphalt mixtures using the three-stage testing methodology. Utilizing the circular economy, RPB have been introduced as a solution to the problem. Results indicated that in the first phase, the addition of RPB on the mixture surface improved the mechanical performance of the road pavement and helped in avoiding road accidents due to their ability to absorb the light from the source and then reflect in the night. Moreover, the mechanical properties using Marshall stability standard parameters (stability 9 kN and flow 2–4 mm range) were fulfilled as a standard testing requirement. The proposed radium bead layer can reduce road accidents and provide a direction towards future smart highways by using new reflective materials in road construction. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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13 pages, 2271 KiB

Open AccessArticle

Utilization of Self-Consolidated Green Material for Sustainable Development: An Environment Friendly Waste Materials Application for Circular Economy

by Syyed Adnan Raheel Shah, Hassam Ahmad, Hatem Alhazmi, Muhammad Kashif Anwar and Fahad Iqbal

Polymers 2021, 13(17), 2985; https://doi.org/10.3390/polym13172985 - 3 Sep 2021

Cited by 5 | Viewed by 3325

Abstract

Self-Compacting Concrete (SCC) is a unique kind of concrete that tends to consolidate in terms of its weight. In this study, the prime target is to investigate the durability properties of SCC developed using eco-friendly economical waste binding materials as partial replacement to [...] Read more.

Self-Compacting Concrete (SCC) is a unique kind of concrete that tends to consolidate in terms of its weight. In this study, the prime target is to investigate the durability properties of SCC developed using eco-friendly economical waste binding materials as partial replacement to costly cement. This circular economy concept will not only help in the development of green concrete but will also help to improve the climatic condition by reducing the use and production of cement. An economical design methodology has been applied to produce environmentally friendly construction material. This research focuses on the application of Alum Sludge (AS) and Brick Dust (BD) in Self-Compacting Concrete (SCC). Both materials are waste materials containing binding properties. Performance of SCC developed using these two materials was tested considering mechanical properties of concrete using the destructive testing technique. Results showed that BD and AS can be utilized for up to 12% and 9% of replacement of cement, respectively, to achieve equal or higher compressive, tensile, and flexural strength. The application of BD and AS has demonstrated a subsequent improvement of SCC’s mechanical properties, i.e., compressive, tensile, and flexural strength. This study will help the production of composite green materials with the help of eco-friendly and economical waste materials for sustainable infrastructure development. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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39 pages, 4683 KiB

Open AccessEditor’s ChoiceArticle

Utilization of Polymer Concrete Composites for a Circular Economy: A Comparative Review for Assessment of Recycling and Waste Utilization

by Hatem Alhazmi, Syyed Adnan Raheel Shah, Muhammad Kashif Anwar, Ali Raza, Muhammad Kaleem Ullah and Fahad Iqbal

Polymers 2021, 13(13), 2135; https://doi.org/10.3390/polym13132135 - 29 Jun 2021

Cited by 30 | Viewed by 8300

Abstract

Polymer composites have been identified as the most innovative and selective materials known in the 21st century. Presently, polymer concrete composites (PCC) made from industrial or agricultural waste are becoming more popular as the demand for high-strength concrete for various applications is increasing. [...] Read more.

Polymer composites have been identified as the most innovative and selective materials known in the 21st century. Presently, polymer concrete composites (PCC) made from industrial or agricultural waste are becoming more popular as the demand for high-strength concrete for various applications is increasing. Polymer concrete composites not only provide high strength properties but also provide specific characteristics, such as high durability, decreased drying shrinkage, reduced permeability, and chemical or heat resistance. This paper provides a detailed review of the utilization of polymer composites in the construction industry based on the circular economy model. This paper provides an updated and detailed report on the effects of polymer composites in concrete as supplementary cementitious materials and a comprehensive analysis of the existing literature on their utilization and the production of polymer composites. A detailed review of a variety of polymers, their qualities, performance, and classification, and various polymer composite production methods is given to select the best polymer composite materials for specific applications. PCCs have become a promising alternative for the reuse of waste materials due to their exceptional performance. Based on the findings of the studies evaluated, it can be concluded that more research is needed to provide a foundation for a regulatory structure for the acceptance of polymer composites. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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11 pages, 2636 KiB

Open AccessArticle

Recycling and Utilization of Polymers for Road Construction Projects: An Application of the Circular Economy Concept

by Muhammad Kashif Anwar, Syyed Adnan Raheel Shah and Hatem Alhazmi

Polymers 2021, 13(8), 1330; https://doi.org/10.3390/polym13081330 - 19 Apr 2021

Cited by 27 | Viewed by 6222

Abstract

Numerous environmental issues arise as a result of a linear economy strategy: reserves become scarce and end up in landfills and as greenhouse gases. Utilizing waste as a resource or shifting towards a circular economy are among the effective strategies for addressing these [...] Read more.

Numerous environmental issues arise as a result of a linear economy strategy: reserves become scarce and end up in landfills and as greenhouse gases. Utilizing waste as a resource or shifting towards a circular economy are among the effective strategies for addressing these issues. To track this shift, appropriate measures that concentrate on sustainable development while taking practical contexts into consideration are required. In this paper, we utilize plastic wastes as a replacement for bitumen for reuse aiming at a circular economy. The use of plastic waste materials, i.e., plastic bottles (PET) and gas pipes (PE) in asphalt materials as a bitumen modifier was studied through series of experimental lab test methods. Marshall samples were prepared using a conventional Marshall method containing five different percentages (0%, 5%, 10%, 15%, and 20%) of plastic content by total weight of bitumen. Samples were tested after 1 and 30 days and the result shows that the stability of plastic-modified asphalt concrete was increased after 30 days, while still meeting standard criteria with plastic contents up to 20%. Moreover, the addition of waste plastic in road construction is a very effective strategy for reusing plastic waste, which also provides economic and social benefits for a sustainable approach to road pavements. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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25 pages, 4922 KiB

Open AccessEditor’s ChoiceArticle

Ecological Design of New Efficient Energy-Performance Construction Materials with Rigid Polyurethane Foam Waste

by Raúl Briones-Llorente, Ricardo Barbosa, Manuela Almeida, Eduardo Atanasio Montero García and Ángel Rodríguez Saiz

Polymers 2020, 12(5), 1048; https://doi.org/10.3390/polym12051048 - 3 May 2020

Cited by 20 | Viewed by 4073

Abstract

An ecological mortar is designed from industrial sub-products, with the objective of utilizing both the slag residues, generated during steel manufacturing processes, and the waste from Polyurethane Foam (PF) panels, generated during refrigerator chamber manufacturing processes. The ecological mortar design involves the dosing [...] Read more.

An ecological mortar is designed from industrial sub-products, with the objective of utilizing both the slag residues, generated during steel manufacturing processes, and the waste from Polyurethane Foam (PF) panels, generated during refrigerator chamber manufacturing processes. The ecological mortar design involves the dosing of Electric Arc Furnace (EAF) slag, together with finely ground Polyurethane Foam, cement, and additives. An energy efficient prefabricated block is designed with the mortar, for use in construction, and its energy performance is assessed as a material inserted within the envelope of a service sector (hospital) building, either as an exterior skin, or as an enclosing component within the façade interior. The main contribution of this research is the characterization of the thermo-physical and mechanical properties of a new prefabricated panel made with recycled materials. The full characterization of the properties of these new materials is presented and discussed. The new prefabricated panel demonstrates adequate thermo-mechanical characteristics as a substitute for traditional materials, while improving the sustainability of the building. As a secondary objective, the energy behaviour of the new panels when integrated in a real building is presented by means of a case study simulation. The use of computational thermal simulation confirmed that the properties of the prefabricated block influenced the annual thermal demand of the building for heating and cooling. Improvements to the thermal inertia of the building envelope were also confirmed with the inclusion of PF waste, giving the mortar an energy performance that was similar to conventional materials, in such a way that its use in façade construction may be validated, in addition to its environmental benefits, due to it having been manufactured with critical recycled industrial waste such as EAF slag and PF, thereby contributing to both the circular economy and sustainable development. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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Review

Jump to: Research

21 pages, 2134 KiB

Open AccessReview

Eco-Design of Polymer Matrix Composite Parts: A Review

by Sergiu Lazăr, Dan Dobrotă, Radu-Eugen Breaz and Sever-Gabriel Racz

Polymers 2023, 15(17), 3634; https://doi.org/10.3390/polym15173634 - 2 Sep 2023

Cited by 7 | Viewed by 2578

Abstract

This research presents a series of analyses related to the eco-design of polymer matrix composite parts, addressing various aspects of it. The main objective was to clarify the definition of ecological design, the benefits of its implementation and its importance in all stages [...] Read more.

This research presents a series of analyses related to the eco-design of polymer matrix composite parts, addressing various aspects of it. The main objective was to clarify the definition of ecological design, the benefits of its implementation and its importance in all stages of obtaining a product (design, manufacturing, recycling). Global environmental issues are presented, emphasizing the importance of adopting sustainable approaches in product design and manufacturing. Special attention is paid to the analysis of waste recycling technologies for polymer matrix composite materials. The analysis carried out identifies specific ecological design principles applicable to these materials and presents recent trends in the field. Relevant case studies are highlighted, demonstrating the benefits of ecological design in order to obtain sustainable products. Additionally, the conducted research allowed for finding answers to the questions “what”, “why”, “when” and “how” it is necessary to apply the principles of eco-design in the case of composite materials with a polymer matrix. In general, the research promotes eco-design as an indispensable strategy for sustainable and responsible production, inspiring companies to adopt these principles for the benefit of the environment and their business performance. Full article

(This article belongs to the Special Issue Polymers and the Circular Economy Model)

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