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1.
Polymers (Basel) ; 14(12)2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35746073

RESUMO

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.

2.
Polymers (Basel) ; 14(9)2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35566942

RESUMO

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.

3.
Materials (Basel) ; 15(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35329707

RESUMO

Water is one of the necessary ingredients for construction materials. Billions of gallons of clean water are wasted during the development of fired clay bricks. Similarly, the waste of clean water is a global issue. In this study, we develop fired clay bricks with the help of wastewater for the first time and compare these with clay bricks produced using groundwater, which is the conventional method. Both destructive (i.e., compressive strength (CS)) and non-destructive (i.e., ultrasonic pulse velocity (UPV)) tests are conducted on all fired clay brick specimens as per the American Society for Testing and Materials (ASTM). Physical (i.e., dimensions) and durability (water absorption, efflorescence, etc.) tests are also conducted. All kinds of brick satisfied the standard requirements of physical and durability characteristics. Similar or better strength of bricks were achieved using wastewater. The study concludes that the testing results of wastewater bricks were significantly 15-25% higher compared with groundwater-fired clay bricks. A large amount of wastewater can be used to develop bricks, and clean water can be saved to attain circular economy goals. Therefore, this study will help not only in developing low-cost bricks but also in saving clean water.

4.
Polymers (Basel) ; 13(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34771263

RESUMO

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.

5.
Polymers (Basel) ; 13(17)2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34503025

RESUMO

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.

6.
Polymers (Basel) ; 13(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209639

RESUMO

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.

7.
Polymers (Basel) ; 13(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203699

RESUMO

In this research, the aim relates to the material characterization of high-energy lithium-ion pouch cells. The development of appropriate model cell behavior is intended to simulate two scenarios: the first is mechanical deformation during a crash and the second is an internal short circuit in lithium-ion cells during the actual effect scenarios. The punch test has been used as a benchmark to analyze the effects of different state of charge conditions on high-energy lithium-ion battery cells. This article explores the impact of three separate factors on the outcomes of mechanical punch indentation experiments. The first parameter analyzed was the degree of prediction brought about by experiments on high-energy cells with two different states of charge (greater and lesser), with four different sizes of indentation punch, from the cell's reaction during the indentation effects on electrolyte. Second, the results of the loading position, middle versus side, are measured at quasi-static speeds. The third parameter was the effect on an electrolyte with a different state of charge. The repeatability of the experiments on punch loading was the last test function analyzed. The test results of a greater than 10% state of charge and less than 10% state of charge were compared to further refine and validate this modeling method. The different loading scenarios analyzed in this study also showed great predictability in the load-displacement reaction and the onset short circuit. A theoretical model of the cell was modified for use in comprehensive mechanical deformation. The overall conclusion found that the loading initiating the cell's electrical short circuit is not instantaneously instigated and it is subsequently used to process the development of a precise and practical computational model that will reduce the chances of the internal short course during the crash.

8.
Polymers (Basel) ; 13(8)2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33921659

RESUMO

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.

9.
Polymers (Basel) ; 13(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924677

RESUMO

Limited research work is available in the literature for the theoretical estimates of axial compressive strength of columns reinforced with fiber reinforced polymer (FRP) rebars. In the present work, an experimental database of 278 FRP-reinforced concrete (RC) compression members was established from the literature to recommend an empirical model that can accurately predict the axial strength (AS) of GFRP-RC specimens. An initial assessment of 13 different previously anticipated empirical models was executed to achieve a general form of the AS model. Finally, a new empirical equation for forecasting the AS of GFRP-RC short columns was proposed using the curve fitting and regression analysis technique. The performance of the proposed empirical model over the previous experimental database represented its higher accuracy as related to that of other models. For the further justification of the anticipated model, a numerical model of GFRP-RC columns was simulated using ABAQUS and a wide parametric study of 600 GFRP-RC samples was executed to generate a numerical database and investigate the influence of various parameters using numerical and empirical models. The comparison between theoretical and numerical predictions with R2 = 0.77 indicted that the anticipated empirical model is accurate enough to apprehend the AS of FRP-RC specimens.

10.
Materials (Basel) ; 13(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143305

RESUMO

Green revolution and high carbon footprint concepts have attracted the development of a green and sustainable environment. This work endeavors to investigate the behavior of recycled aggregate geopolymer concrete (RAGC) developed with four different types of effluents to develop sustainability in the construction industry and to produce an eco-friendly environment. Each of the types of effluents was used by completely replacing the freshwater in RAGC to examine its influence on compressive strength (CS), chloride ion migration (CIM), split tensile strength (STS), and resistance to the sulfuric acid attack of RAGC at various testing ages. The test outputs portray that the effluent obtained from the textile mill performed well for the CS (25% higher than the control mix) and STS (17% higher than the control mix) of RAGC. Similarly, the highest mass loss of RAGC due to the acid attack (41% higher than control mix) and the highest CIM (29% higher than control mix) were represented by the RAGC mix made with effluent obtained from fertilizer mill. The statistical analysis indicated no significant influence of using textile mill effluent (TE), fertilizer mill effluent (FE), and sugar mill effluent (SE) on the STS, CIM, and mass loss due to acid attack while it presented a significant influence on the CS of various mixes. Therefore, this investigation solidly substantiates the acceptability of studied types of effluents for the fabrication of eco-friendly green materials.

11.
Int J Inj Contr Saf Promot ; 27(3): 308-318, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32466686

RESUMO

Accident risk analysis for human safety and infrastructural improvement are key requirements of the engineering sector. The purpose of this paper is to identify and prioritize problematic segments of roads based upon the risk evaluation concept and to focus on the severity of accidents regarding human life loss and easy manoeuvring. This study includes the concept of considering road segments as decision-making units for application of data envelopment analysis (DEA) technique which has no compulsion of the distribution function and critical assumptions, unlike the multiple regression models. According to the proposed methodology, a section of Motorway (M-2) Lahore-Islamabad has been analyzed. Out of 200 segments under consideration, 99 segments were selected with at least one accident and one injury or fatality. Furthermore, for risk calculation and ranking of road segments, the DEA technique along with the cross-risk matrix method was applied. This optimization technique could not only be helpful in ranking but also technical decision-making and prioritizations for safety improvement, policymaking and budget allocation.


Assuntos
Acidentes de Trânsito , Benchmarking , Segurança , Humanos , Modelos Estatísticos , Análise de Regressão , Medição de Risco/métodos
12.
Artigo em Inglês | MEDLINE | ID: mdl-31963777

RESUMO

Urbanization is playing a key role in big cities of developing countries, which, in effect, is increasing the population. This study takes care of the mega infrastructure project (Orange Line Metro Train (OLMT)) to explore and identify the H&S (Health and Safety) factors that affect the local residents and the main key stakeholders working on the project. A Sequential Mixed-Method approach of the OLMT-project includes qualitative and quantitative methods were adopted. The data have been collected from the targeted population working on the OLMT-project through a questionnaire. The main key finding of the study indicates that poor planning and a lack of communication between the public and government led to frustration. The most significant factors that identified in the study were unsafe to work practice, project scope constraints, lack in technical and material support, unsafe/bad condition, health/environment degradation, declination and loss of resources and time, no proper emergency system, and negligence in adopting safety rules and laws. The study also revealed that the consensus should also be noticed between the key stakeholders (e.g., contractors, clients, safety officials, academia) in the second round of the Delphi survey of the project. The study findings will help the key stakeholders to prioritize their energies towards attaining zero levels of inadequate health and safety practices in infrastructure projects. The study outcomes can also be generalized for the other developing countries having a similar work scenario.


Assuntos
Indústria da Construção , Serviços de Saúde/estatística & dados numéricos , Saúde Ocupacional/estatística & dados numéricos , Cidades , Países em Desenvolvimento , Humanos , Paquistão , Urbanização
13.
J Safety Res ; 69: 201-215, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31235230

RESUMO

INTRODUCTION: An efficient decision-making process is one of the major necessities of road safety performance analysis for human safety and budget allocation procedure. METHOD: During the road safety analysis procedure, data envelopment analysis (DEA) supports policymakers in differentiating between risky and safe segments of a homogeneous highway. Cross-risk, an extension of the DEA models, provides more information about risky segments for ranking purpose. After identification of risky segments, the next goal is to identify the factors that are major contributors in making that segment risky. RESULTS: This research proposes a methodology to analyze road safety performance by using a combination of DEA with the decision tree (DT) technique. The proposed methodology not only provides a facility to identify problematic road segments with the help of DEA but also identifies contributing factors with the help of DT. Practical applications: The applicability of the proposed model will help policymakers to identify the major factors contributing to road accidents and analysis of safety performance of road infrastructure to allocate the budget during the decision-making process.


Assuntos
Acidentes de Trânsito/prevenção & controle , Tomada de Decisões , Planejamento Ambiental/normas , Meios de Transporte/normas , Acidentes de Trânsito/estatística & dados numéricos , Humanos , Formulação de Políticas
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