scholarly journals Gap between simplified and detailed calculation of the environmental impacts of road mixtures

2021 ◽  
Vol 2042 (1) ◽  
pp. 012175
Author(s):  
Endrit Hoxha ◽  
Rolf André Bohne ◽  
Alexander Passer

Abstract In order to reach the COP21 objectives, solutions with low carbon contents must be used in road projects. However, the identification of the best materials to be implemented in the wearing course of roads is a daily problem faced by stakeholders. To overcome this knowledge gap, the present study demonstrates the environmental impacts of 120 mixtures calculated with simplified and detailed hypotheses and input data. Even though the variability of inputs significantly influences the impacts of the mixtures and do not allow for the identification of the best solutions, on average, warm mix asphalt presented lower impacts than hot mix asphalt or concrete.

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Hui Ma ◽  
Zhigang Zhang ◽  
Xia Zhao ◽  
Shuang Wu

Generally, the warm mix asphalt (WMA) technology can reduce the mixing and paving temperature effectively as compared with that of hot mix asphalt (HMA), which is considered more environment-friendly. In this study, the environmental impacts and resource consumptions of WMA and HMA pavements were analyzed comparatively using the life cycle assessment (LCA) method. A LCA model of pavement was built; meanwhile, the relevant life cycle inventory (LCI) of WMA and HMA pavements was also collected and analyzed. The midpoint impact categories including Global Warming Potential (GWP), Chinese Abiotic Depletion Potential (CADP), and Particulate Matter Formation (PMF) were assessed for five cases. The assessment results showed that the resource consumptions of both WMA and HMA pavements in entire life were almost at the same level, while the environmental impacts of WMA pavement related to greenhouse gases and PM2.5 emissions were significantly less than that of HMA pavement, except for the case where the long-term performance of WMA pavement is much worse than that of HMA pavement. In final, it could be concluded that WMA pavement is more environment-friendly compared with HMA pavement although they have the same-level resource consumptions.


Author(s):  
E. Hoxha ◽  
D. Maierhofer ◽  
M.R.M Saade ◽  
A. Passer

Abstract Purpose A detailed assessment of the environmental impacts of the building requires a substantial amount of data that is time- and effort-consuming. However, limitation of the system boundary to certain materials and components can provide misleading impact calculation. In order to calculate the error gap between detailed and simplified assessments, the purpose of this article is to present a detailed calculation of the environmental impacts of the building by including in the system boundary, the technical, and electrical equipment. Method To that end, the environmental impacts of a laboratory and research building situated in Graz-Austria are assessed following the EN-15978 norm. Within the system boundaries of the study, the material and components of building fabric, technical, and electronic equipment for the building lifecycle stages of production, construction, replacement, operational energy and water, and end-of-life are considered. The input data regarding the quantity of materials is collected from the design and tendering documents, invoices, and from discussion with the head of the building’s construction site. Primary energy and global warming potential indicators are calculated on the basis of a functional unit of 1 m2 of energy reference area (ERA) per year, considering a reference building service life of 50 years. Results and discussion The primary energy indicator of the building is equal to 1698 MJ/m2ERA/year. The embodied impacts are found to be responsible for 28% of which 6.4% is due to technical and electronic equipment. Furthermore, the embodied impacts for the global warming potential, equal to 28.3 kg CO2e/m2ERA/year, are responsible for 73%. Together, technical and electrical equipment are the largest responsible aspects, accounting for 38% of the total impacts. Simplified and detailed result comparisons show a gap of 29% and 7.7% for global warming and primary energy indicators. These differences were from the embodied impacts and largely from the exclusion of electrical equipment from the study’s system boundary. Conclusions Technical and electrical equipment present a significant contribution to the overall environmental impacts of the building. Worthy of inclusion in the system boundary of the study, the environmental impacts of technical and electrical equipment must be calculated in detail or considered with a reliable ratio in the early design phase of the project. Further research is necessary to address the detailed impact calculation of the equipment and notably the minimization of their impacts.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1415
Author(s):  
Václav Voltr ◽  
Martin Hruška ◽  
Luboš Nobilis

This paper provides values of economic, energy and environmental assessments of 20 crops and assesses the relationships of soil-climatic conditions in the example of the Czech Republic. The comparison of main soil quality indicators according to the configuration of land and climate regions is performed on the basis of energy and economic efficiency as well as a comparison of the level of environmental impacts. The environmental impacts are identified based on the assessment of emissions from production and also in the form of soil compaction as an indicator of the relationship to soil quality. As concerns soil properties, of major importance is soil skeleton, slope of land and the depth of soil, which cause an increase in emissions from the energy produced. Substantially better emission parameters per 1 MJ through energy crops, the cultivation of perennial crops and silage maize has been supported. Among energy crops, a positive relationship with the quality of soil is seen in alfalfa, with a significant reduction in soil penetrometric resistance; energy crops are also politically justifiable in competition with other crops intended for nutrition of population. The main advantage of energy crops for the low-carbon economy is their CO2 production to MJ, which is almost half, especially in marginal areas with lower soil depths, slopes and stoniness, which can be included in the new agricultural policy.


2013 ◽  
Vol 20 (1) ◽  
pp. 256-266 ◽  
Author(s):  
Ziari Hasan ◽  
Behbahani Hamid ◽  
Izadi Amir ◽  
Nasr Danial

2021 ◽  
Vol 11 (8) ◽  
pp. 3708
Author(s):  
Adham Mohammed Alnadish ◽  
Mohamad Yusri Aman ◽  
Herda Yati Binti Katman ◽  
Mohd Rasdan Ibrahim

The major goal of sustainable practices is to preserve raw resources through the utilization of waste materials as an alternative to natural resources. Decreasing the temperature required to produce asphalt mixes contributes to environmental sustainability by reducing energy consumption and toxic emissions. In this study, warm mix asphalt incorporating coarse steel slag aggregates was investigated. Warm mix asphalt was produced at different temperatures lower than the control asphalt mixes (hot mix asphalt) by 10, 20, and 30 °C. The performances of the control and warm mix asphalt were assessed through laboratory tests examining stiffness modulus, dynamic creep, and moisture sensitivity. Furthermore, a response surface methodology (RSM) was conducted by means of DESIGN EXPERT 11 to develop prediction models for the performance of warm mix asphalt. The findings of this study illustrate that producing warm mix asphalt at a temperature 10 °C lower than that of hot mix asphalt exhibited the best results, compared to the other mixes. Additionally, the warm mix asphalt produced at 30 °C lower than the hot mix asphalt exhibited comparable performance to the hot mix asphalt. However, as the production temperature increases, the performance of the warm mix asphalt improves.


Author(s):  
Natasha Järviö ◽  
Tuure Parviainen ◽  
Netta-Leena Maljanen ◽  
Yumi Kobayashi ◽  
Lauri Kujanpää ◽  
...  

2017 ◽  
Vol 156 ◽  
pp. 574-583 ◽  
Author(s):  
Shenghua Wu ◽  
Weiguang Zhang ◽  
Shihui Shen ◽  
Xiaojun Li ◽  
Balasingam Muhunthan ◽  
...  

2019 ◽  
Vol 48 (5) ◽  
pp. 363-374 ◽  
Author(s):  
Abdelrahman Moukhtar Naser ◽  
Hamada Abd El - Wahab ◽  
Mohamed Abd El Fattah Moustafa El Nady ◽  
Abdelzaher E.A. Mostafa ◽  
Long Lin ◽  
...  

Purpose This paper aims to investigate the best methods of utilisation of reclaimed asphalt pavements (RAP) in Egypt, to determine the effect of using 100% RAP instead of using virgin aggregates and asphalt; investigate the effect of thermoplastic elastomer polymer as asphalt modifier; and also improve the mechanical and physical characteristics and consequently improving the quality of asphalt paving, increasing service life of asphalt-paving and reducing costs. Design/methodology/approach Nano acrylate terpolymers were prepared with different % (Wt.) of and were characterised by Fourier transforms infrared (FTIR), for molecular weight (Mw), by thermo gravimetric analysis (TGA) and by transmission electron microscopy (TEM). A 4% (Wt.) of the prepared nanoemulsion terpolymer was mixed with virgin asphalt as a polymer modifier, to improve and reuse of the RAP. The modified binder was tested. The tests conducted include penetration, kinematic viscosity, softening point and specific gravity. Application of Marshall mix design types; hot mix asphalt (HMA), warm mix asphalt (WMA) and cold in place recycled (CIR). Four different mix designs used; control mix contained virgin asphalt by HMA, and the other three mix designs were polymermodified asphalt sample by HMA, WMA and CIR. Findings The research results showed that using 4 Wt.% of the prepared nanoemulsion terpolymer to produce hot mix asphalt (HMA) and warm mix asphalt (WMA) achieved higher stability compared to the control mix and cold in place recycled (CIR). Research limitations/implications This paper discusses the preparation and the characterisation of nanoemulsion and its application in RAPs to enhance and improve the RAP quality. Practical implications Nano-acrylate terpolymer can be used as a new polymer to modify asphalt to achieve the required specifications for RAP. Originality/value According to the most recent surveys, Europe produced 265 tonnes of asphalt for road applications in 2014, while the amount of available RAP was more than 50 tonnes. The use of RAP in new blended mixes reduces the need of neat asphalt, making RAP recycling economically attractive.


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