scholarly journals Environmental and Economic Life Cycle Assessment of Recycled Coarse Aggregates: A Portuguese Case Study

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 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.


2013 ◽  
Vol 742 ◽  
pp. 379-383 ◽  
Author(s):  
Julia García González ◽  
Desirée Rodríguez Robles ◽  
Andrés Juan Valdés ◽  
Julia M. Morán del Pozo ◽  
M. Ignacio Guerra Romero

The use of recycled aggregate to produce new concretes has become increasingly widespread, and numerous studies have demonstrated that the final product performs similarly to traditional concrete. However, construction and demolition waste (CDW) presents certain characteristics which could limit its acceptance in the construction sector due to worse performance than natural aggregates. One example of this is water absorption, which in recycled aggregates reaches such high values that the amount of free water calculated for mixing the concrete is affected, consequently impacting on the concrete's properties, especially consistency. This paper reports the possibility of solving this problem with a simple and inexpensive method; pre-saturation of recycled aggregates prior to adding them to the mix. The results of two different pre-treatments are compared; one consisted of immersing the aggregates in water for 10 minutes and the other, in addition to the above procedure, included a brief period of air drying and subsequent elimination of surface water from the aggregate. Both pre-treatments were found to solve the problem of consistency.


2020 ◽  
Vol 10 (3) ◽  
pp. 1018 ◽  
Author(s):  
Hisham Hafez ◽  
Reben Kurda ◽  
Rawaz Kurda ◽  
Botan Al-Hadad ◽  
Rasheed Mustafa ◽  
...  

The aim of this critical review is to show the applicability of recycled fine aggregates (RFA) in concrete regarding technical performance, environmental impact, energy consumption and cost. It is not possible to judge the performance of concrete by considering one dimension. Thus, this study focussed on the fresh and hardened (e.g., mechanical and durability) properties and environmental and economic life cycle assessment of concrete. Most literature investigated showed that any addition of recycled fine aggregates from construction and demolition waste as a replacement for natural fine aggregates proves detrimental to the functional properties (quality) of the resulting concrete. However, the incorporation of recycled fine aggregates in concrete was proven to enhance the environmental and economic performance. In this study, an extensive literature review based multi criteria decision making analysis framework was made to evaluate the effect of RFA on functional, environmental, and economic parameters of concrete. The results show that sustainability of RFA based concrete is very sensitive to transportation distances. Several scenarios for the transportation distances of natural and recycled fine aggregates and their results show that only if the transportation distance of the natural aggregates is more than double that of RFA, e the RFA based concrete alternatives would be considered as more sustainable.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3867
Author(s):  
Cristina Oreto ◽  
Francesca Russo ◽  
Rosa Veropalumbo ◽  
Nunzio Viscione ◽  
Salvatore Antonio Biancardo ◽  
...  

The pursuit of sustainability in the field of road asphalt pavements calls for effective decision-making strategies, referring to both the technical and environmental sustainability of the solutions. This study aims to compare the life cycle impacts of several pavement solution alternatives involving, in the binder and base layers, some eco-designed, hot- and cold-produced asphalt mixtures made up of recycled aggregates in substitution for natural filler and commercial recycled polymer pellets for dry mixture modification. The first step focused on the technical and environmental compatibility assessment of the construction and demolition waste (CDW), jet grouting waste (JGW), fly ash (FA), and reclaimed asphalt pavement (RAP). Then, three non-traditional mixtures were designed for the binder layer and three for the base layer and characterized in terms of the stiffness modulus. Asphalt pavement design allowed for the definition of the functional units of Life Cycle Assessment (LCA), which was applied to all of the pavement configurations under analysis in a “from cradle to grave” approach. The LCA results showed that the best performance was reached for the solutions involving a cold, in-place recycled mixture made up of RAP and JGW in the base layer, which lowered all the impact category indicators by 31% on average compared to those of the traditional pavement solution. Further considerations highlighted that the combination of a cold base layer with a hot asphalt mixture made up of CDW or FA in the binder layer also maximized the service life of the pavement solution, providing the best synergistic effect.


2020 ◽  
Vol 23 ◽  
Author(s):  
Laís Peixoto Rosado ◽  
Carmenlucia Santos Giordano Penteado

Abstract Fiscal economic instruments are one of the main mechanisms to improve the management of construction and demolition waste (C&DW), and the establishment of specific disposal fees is one of the most effective practices. This study analyzed the influence of increasing C&DW disposal fees considering a municipal management system. The environmental profile of the current scenario and the proposed scenarios, designed in accordance with the adoption of economic fiscal instruments, were determined through life cycle assessment. The results indicated that the scenario proposed for 2030 (350% increase in disposal fees compared to 2017) has the lowest environmental impact, indicating the potential benefits of using tax instruments.


2018 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Nadia Qamar ◽  
Ayesha Alam Khurram

In Pakistan, construction and demolition waste(CDW) is generated in voluminous amount each year. CDW iswidely ill-handled and ultimately fed to landfills causing harm tothe already alarming environmental conditions. In order tosearch for the solution of this drastic matter, a study was done,which is explained in this paper. This paper presents the studydone at a demolition site near Karachi, in Sindh while thedemolition works were being carried out. At the site there wereold barracks which were being demolished. Before the demolitionworks were commenced, the site was surveyed and structuralcomponents of the barracks were counted and their dimensionswere measured. When the demolition was over, the demolishedwaste was calculated which comprised of concrete and masonryrubble, steel round bars, steel doors, steel windows, steel ceiling,steel girders, steel main gate, and plastic water tank. This studyinterpreted that construction and demolition (C&D) works wereprogressing considering the works’ deadline and the clients’requirements but the ecosystem’s ecology and the environmentalhealth were not taken into account. Recommendations are madeto handle CDW properly throughout its lifecycle. Theserecommendations aim to provide technological and logicalsolutions to grip CDW. The recommendations include wastereduction and reusing waste, life cycle assessment and costing,environmental and economic impact, material flow analysis, andadvanced computerized-tools.


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