scholarly journals Environmental and Economic Life Cycle Assessment of Recycled Aggregates Concrete in the United Arab Emirates

2021 ◽  
Vol 13 (18) ◽  
pp. 10348
Author(s):  
Mohammed H. Alzard ◽  
Hilal El-Hassan ◽  
Tamer El-Maaddawy

This paper studies the potential environmental and economic impact of replacing natural aggregates (NA) with recycled aggregates (RA) in the production of different sustainable concrete mixes in the United Arab Emirates (UAE). A life cycle assessment (LCA) was carried out according to the methodology proposed by the international standards of the series ISO 14040. The performance of concrete mixes having a similar design compressive strength was evaluated. Results showed that the inclusion of steel fibers (SF) led to an increase in the global warming potential (GWP), whereas mixes with cement replacement by fly ash, slag, or microsilica recorded a reduction in GWP. Furthermore, SF-reinforced mixes created with 100% RA were at least three times more expensive than the NA-based control mix, while the cost of those with cement replacement by mineral additives was generally similar to that of the control. Material transportation was found to be a main contributor to the environmental and economic impacts, only second to cement, and its contribution increased with longer distances and steel fiber incorporation and decreased with RA replacement. To integrate these individual measures and select optimum mixes for various applications, multifunctional performance indices were developed. Research findings highlight the possibility to fully replace NA with RA (100%) while maintaining the performance and improving the economic and environmental impacts of concrete produced in the UAE.

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5452
Author(s):  
Adriana B. Dias ◽  
João N. Pacheco ◽  
José D. Silvestre ◽  
Isabel M. Martins ◽  
Jorge de Brito

The incorporation of recycled aggregates in concrete not only reduces the extraction of natural resources, but also decreases landfill disposal of construction and demolition waste. Hence, environmental impacts and costs are reduced, promoting the use of recycled aggregates and circular economy. However, the impacts of transport depend on the distance between facilities and longer distances may result in recycled aggregates being more costly and having larger environmental impact than natural aggregates. This paper discusses this topic, presents a review on the use of life cycle assessment methodology on natural and recycled aggregates for concrete, and applies this methodology in a real context pertaining the procurement of coarse aggregates to ready-mix concrete plants. A case study of two Portuguese regions, Coimbra and Lisbon, is presented. For each region, a quarry, a construction and demolition waste plant, and a ready-mix concrete plant are chosen and a comparative life cycle assessment is made. Different scenarios for the supply of natural and recycled aggregates are studied and the scenarios for recycled aggregates procurement include different hypotheses for the installation (construction and demolition waste plant or quarry) processing the construction and demolition waste into recycled aggregates. For this case study and both regions, it was found that the supply of recycled aggregates produced at the construction and demolition waste plant has lower environmental impact and cost than all other scenarios, including the provision of natural aggregates, except when it is assumed that the quarry is licensed and equipped for receiving unsorted construction and demolition waste and processing it into recycled aggregates. The paper shows that transport distance is a determining factor in the comparison of the impacts of the procurement of natural and recycled aggregates. Moreover, in the Portuguese context, the environmental impacts of the procurement of recycled aggregates may be smaller than those of natural aggregates, but cost may be larger for recycled aggregates, preventing that the most sustainable option is chosen.


2021 ◽  
Vol 11 (4) ◽  
pp. 1423
Author(s):  
José Manuel Salmerón Lissen ◽  
Cristina Isabel Jareño Escudero ◽  
Francisco José Sánchez de la Flor ◽  
Miriam Navarro Escudero ◽  
Theoni Karlessi ◽  
...  

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.


2013 ◽  
Vol 17 (5) ◽  
pp. 438-450 ◽  
Author(s):  
Sabina Abdul Hadi ◽  
Muna R. Al Kaabi ◽  
Meshayel O. Al Ali ◽  
Hassan A. Arafat

2013 ◽  
Vol 31 (3) ◽  
pp. 169-176 ◽  
Author(s):  
Dewayne L. Ingram ◽  
Charles R. Hall

Life cycle assessment (LCA) was utilized to analyze the global warming potential (GWP), or carbon footprint, and associated costs of the production components of a field-grown, spade-dug, 5 cm (2 in) caliper Cercis canadensis ‘Forest Pansy’ in the Lower Midwest, U.S. A model production system was determined from interviews of nursery managers in the region. Input materials, equipment use and labor were inventoried for each production system component using international standards of LCA. The seed-to-landscape GWP, expressed in kilograms of carbon dioxide emission equivalent (CO2e), was determined to be 13.707. Equipment use constituted the majority (63%) of net CO2-e emissions during production, transport to the customer, and transplanting in the landscape. The model was queried to determine the possible impact of production system modifications on carbon footprint and costs to aid managers in examining their production system. Carbon sequestration of a redbud growing in the landscape over its 40 year life, weighted proportionally for a 100 year assessment period, was calculated to be −165 kg CO2e. The take-down and disposal activities following its useful life would result in the emission of 88.44 kg CO2e. The life-cycle GWP of the described redbud tree, including GHG emissions during production, transport, transplanting, take down and disposal would be −63 kg CO2e. Total variable costs associated with the labor, materials, and equipment use incurred in the model system were $0.069, $2.88, and $34.81 for the seedling, liner, and field production stages, respectively. An additional $18.83 was needed for transport to the landscape and planting in the landscape and after the 40 year productive life of the tree in the landscape, another $60.86 was needed for take-down and disposal activities.


2021 ◽  
Vol 13 (17) ◽  
pp. 9625
Author(s):  
Ambroise Lachat ◽  
Konstantinos Mantalovas ◽  
Tiffany Desbois ◽  
Oumaya Yazoghli-Marzouk ◽  
Anne-Sophie Colas ◽  
...  

The demolition of buildings, apart from being energy intensive and disruptive, inevitably produces construction and demolition waste (C&Dw). Unfortunately, even today, the majority of this waste ends up underexploited and not considered as valuable resources to be re-circulated into a closed/open loop process under the umbrella of circular economy (CE). Considering the amount of virgin aggregates needed in civil engineering applications, C&Dw can act as sustainable catalyst towards the preservation of natural resources and the shift towards a CE. This study completes current research by presenting a life cycle inventory compilation and life cycle assessment case study of two buildings in France. The quantification of the end-of-life environmental impacts of the two buildings and subsequently the environmental impacts of recycled aggregates production from C&Dw was realized using the framework of life cycle assessment (LCA). The results indicate that the transport of waste, its treatment, and especially asbestos’ treatment are the most impactful phases. For example, in the case study of the first building, transport and treatment of waste reached 35% of the total impact for global warming. Careful, proactive, and strategic treatment, geolocation, and transport planning is recommended for the involved stakeholders and decision makers in order to ensure minimal sustainability implications during the implementation of CE approaches for C&Dw.


2012 ◽  
pp. 860-878
Author(s):  
Antti Sirkka ◽  
Marko Junkkari

Monitoring the environmental performance of a product is recognized to be increasingly important. The most common method of measuring the environmental performance is the international standards of Life Cycle Assessment (LCA). Typically, measuring is based on estimations and average values at product category level. In this chapter, the authors present a framework for measuring environmental impact at the item level. Using Traceability Graph, emissions and resources can be monitored from the data management perspective. The model can be mapped to any precision level of physical tracing. At the most precise level, even a single physical object and its components can be analyzed. This, of course, demands that the related objects and their components are identified and mapped to the database. From the opposite perspective, the authors’ model also supports rough level analysis of products and their histories. In terms of the Traceability Cube, multidimensional analysis can be applied for traceability data.


2018 ◽  
Vol 64 (No. 5) ◽  
pp. 216-223 ◽  
Author(s):  
Hejazian Mohammad ◽  
Lotfalian Majid ◽  
Limaei Soleiman Mohammadi

This study was conducted in order to estimate the economic life of two models of rubber-tired skidders, namely Timberjack 450C and HSM 904, in Iranian Caspian forests. The total annual costs and average cumulative cost of skidders were calculated by life-cycle costing analysis. The economic life of the machines was estimated by both the cumulative cost model and cost minimization model. The results indicated that the economic life of Timberjack 450C and HSM 904 is 7,700 h (at the end of the 11<sup>th</sup> year) and 15,300 h (at the end of the 17<sup>th</sup> year), respectively, using the cost minimization model. Furthermore, the results indicated that the economic life of Timberjack 450C and HSM 904 is 9,100 h (at the end of the 13<sup>th</sup> year) and 11,900 h (at the end of the 21<sup>st</sup> year), respectively, using the cumulative cost model. The cumulative cost model estimated the economic life of skidders longer than the cost minimization model.


2020 ◽  
Vol 265 ◽  
pp. 121705 ◽  
Author(s):  
Rúben Santos ◽  
António Aguiar Costa ◽  
José D. Silvestre ◽  
Lincy Pyl

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