Influence of Crushing Conditions on Recycled Concrete Aggregates (RCA) Leaching Behaviour

Coudray, Coryse; Amant, V.; Cantegrit, L.; Bocq, Agathe Le; Théry, François; Denot, A.; Eisenlohr, Laurent

doi:10.1007/s12649-017-9868-2

Cited by 21 publications

(8 citation statements)

References 16 publications

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“…As recently studies reported (Coudray et al, 2017;Gupta et al, 2018;Ng & Engelsen, 2018;Saca et al, 2017), this strong alkalinity is mainly due to the cement and concrete fractions contained in both CDWs and RAs. In agreement with these considerations, as shown in Figure 7 (b), EWC 170101 "cement" had the highest pH values with a median of 11.3 and highly left-skewed data.…”

Section: Leaching Behaviourmentioning

confidence: 71%

Technical analysis of full-scale Construction and Demolition Waste treatment plants: case studies of the Lombardy Region, Italy

2021

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Construction and demolition activities in Italy and the Lombardy Region produce a considerable amount of wastes that can be valorised as secondary raw materials. The recovery of construction and demolition wastes is severely limited by the lack of consolidated and sustainable treatment chains and by the strong variability of their environmental characteristics that may generate potentially dangerous effects for the environment. The purpose of this study was to evaluate and technically define the current treatment chains in the Province of Brescia (Lombardy) by analyzing three full-scale treatment plants in order to highlight barriers to demolition waste recovery and propose possible solutions and improvement strategies. To best represent the entire management and treatment system, the analysis was developed on all the acceptance, treatment, and final quality control phases. Moreover, chemical composition and leaching data on demolition wastes and recycled aggregates were collected from the three treatment plants and statistically analyzed to assess their potential recovery according to the Italian legislation. Mixed non-hazardous waste is the fraction mostly managed by recycling plants and mixed recycled aggregates are the main products obtained from the treatment. These are mostly used in roads and in geotechnical applications. Chemical composition results showed that the pH is generally alkaline and tin and benzene are the most critical elements for both demolition wastes and recycled aggregates with respect to the regulatory limit values. Total chromium was identified as a critical compound in leachates. The results of the statistical analysis confirmed that chromium was mainly released by cement materials.

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Section: Leaching Behaviourmentioning

confidence: 71%

Technical analysis of full-scale Construction and Demolition Waste treatment plants: case studies of the Lombardy Region, Italy

2021

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“…In particular, the particle size of the examined solid determines the surface exposed to the leaching solution, which in many cases influences the release of the contaminant into the solution. In fact, a reduction in particle size leads to an increase in the contact area, which results in a greater release of pollutants [22,23,27]. Mahedi et al [28] confirmed the previous studies, but also stated that the RCA particle sizes had a significant influence not only on the leached concentrations of elements, but also on the effluent pH and alkalinity.…”

Section: Introductionmentioning

confidence: 70%

“…In 2018, the total waste generated by all economic activities and households (EU-27) amounted to 2317 million tons; this was the highest amount recorded during the period of 2008-2014 [6]. According to Eurostat data, the waste from the construction sector accounts for around 37% of total waste of contaminants is also influenced by other factors that regulate the leaching process, such as the pH and carbonation grade, liquid to solid ratio, particle size, or contact time [22][23][24][25][26]. The leaching behavior in construction materials is mainly controlled by the alkaline nature and acid buffering capacity of the stabilized matrix, and metal release presents a pH-dependent process controlled by metal hydroxide solubility [25].…”

Section: Introductionmentioning

confidence: 99%

Chemical and Leaching Behavior of Construction and Demolition Wastes and Recycled Aggregates

et al. 2020

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Construction and demolition wastes are widely recognized as the main waste stream in the EU, and their recycling and recovery is an important issue in sustainable building industry development. The composition of construction and demolition wastes is highly heterogeneous and is influenced by several factors, including the raw materials and construction products used. The environmental performance of these materials are therefore considerably variable and, in some cases, do not comply with the regulatory limits established to ensure the protection of the natural environment. In this context, this paper presents a data analysis on the environmental behavior of construction and demolition wastes and recycled aggregates in terms of both chemical composition and the release of contaminants according to a leaching test. Subsequently, the most critical parameters for recovery were identified and statistically evaluated. The leaching results showed that SO4, Cu, and COD are critical compounds for both CDWs and RAs.

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“…Some authors have analysed concrete RCA with different ages of production, including concrete recently produced in the laboratory. The Coudray's study [42] used concrete 50 years old in RCA production and, on the other hand, Lopez Meza [46] used new concrete formulated in the laboratory. In all analysed studies, RCA produced in the laboratory or collected in recycling centres are constituted by at least 90% of ground concrete and/or mortar elements [48] [51].…”

Section: Recycled Concrete Aggregates Studiesmentioning

confidence: 99%

Toxicity of Recycled Concrete Aggregates: Review on Leaching Tests

Maia¹,

Brito²,

Martins³

et al. 2018

TOBCTJ

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Background:The toxicity of building materials can be addressed in the areas of occupational and environ-mental toxicology. In the first case, the harmful effects to workers caused by exposure to a specific substance during building materials production are analysed. In the latter case, the toxic effects of that substance on living organisms is examined.Several studies analysed the environmental impact of concrete production, considering a significant number of concrete constituents and compositions, in order to find ways of minimizing it. However, some of the traditional constituents of concrete may be potentially hazardous, presenting different levels of toxicity, but only a few studies are focused on this area. Still, and in order to reduce the potential environmental impact, studies have already started on the incorporation of alternative raw materials, which may affect concrete toxicity.It is important to develop more concrete toxicity studies analysing different mixes and constituents, in order to identify several ways of minimizing the potential toxicity of this construction material.Objective:Different procedures and results of the leaching tests of Recycled Concrete Aggregates (RCA) from previous studies will be presented and discussed in this paper.Method:The ecotoxicological characterization of materials is based on the analysis of the eluates resulting from leaching tests. There are several researches that apply different experimental leaching procedures according to existing standards and others with some variations in the standard test conditions: particle size, duration of the test, among others.Results and conclusion:The main characteristics of RCA that affect the results of the leaching tests will be identified.

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Influence of Crushing Conditions on Recycled Concrete Aggregates (RCA) Leaching Behaviour

Cited by 21 publications

References 16 publications

Technical analysis of full-scale Construction and Demolition Waste treatment plants: case studies of the Lombardy Region, Italy

Technical analysis of full-scale Construction and Demolition Waste treatment plants: case studies of the Lombardy Region, Italy

Chemical and Leaching Behavior of Construction and Demolition Wastes and Recycled Aggregates

Toxicity of Recycled Concrete Aggregates: Review on Leaching Tests

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