scholarly journals Recommendations for the Management of Construction and Demolition Waste in Treatment Plants

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1278
Author(s):  
Auxi Barbudo ◽  
Jesús Ayuso ◽  
Angélica Lozano ◽  
Manuel Cabrera ◽  
Antonio López-Uceda

Construction and demolition waste consists approximately of one third waste generated in the European Union. The recycling of this stream waste will provide ecological and sustainable benefits. Recycled aggregates from construction and demolition waste are clearing a path into civil constructions, as substitutes for natural aggregates. The possible applications of recycled aggregates on infrastructure construction projects will depend on the quality of the recycled aggregates mainly. This will be determined by the nature and the origin of the construction and demolition waste, and the treatment system undergone. Hence, this work proposes recommendations for the handling of construction and demolition waste in treatment plants.

2020 ◽  
Vol 38 (4) ◽  
pp. 460-471 ◽  
Author(s):  
John N. Hahladakis ◽  
Phil Purnell ◽  
Hareb Mohammed S.J. Aljabri

Rapid industrial development, mega construction projects and increased immigration are some of the reasons that the State of Qatar has recently generated an unprecedented amount of construction and demolition (C&D) waste in the country. The State is racing towards the Fédération Internationale de Football Association World Cup 2022, a fact that requires additional construction, for which it is expected to increase its rate of waste generation. Compared to other regions, there are relatively few studies in the literature that report on the C&D waste management issues of Qatar. The present work begins to address this gap by providing insights into the current state of C&D waste management practices in Qatar and by providing a mini-review on the benefits of using recycled aggregates which have only recently been allowed locally by Qatar Construction Standards. A Strengths, Weaknesses, Opportunities, and Threats analysis has been implemented, using data and information from various sources including governmental reports, industries, local waste management companies, as well as reported interviews with relevant stakeholders. Finally, several strategies were proposed and developed that could potentially be implemented by stakeholders and decision-makers, so as to improve the current status by encouraging more sustainable and viable practices.


2020 ◽  
Vol 9 (1) ◽  
pp. e56911597
Author(s):  
Pedro Valle Salles ◽  
Thiago Marques Viana ◽  
Camila Lacerda Gomes ◽  
Flávia Cristina Silveira Braga ◽  
Flávia Spitale Jacques Poggiali ◽  
...  

The construction industry is responsible for the generation of large volumes of waste, known as construction and demolition waste (CDW). Around the world, millions of tons of these wastes are generated annually, which often become important environmental liabilities. The situation gets worse as the sector develops. In Europe, only 15 of the 27 countries in the European Union annually produce around 180 million tonnes of CDW, in Brazil, the data about this indicates that in 2014 the municipalities collected about 45 million tons of CDW, quantity 4.1% higher than in 2013. In this scenario, the present study aims to evaluate the partial replacement of natural aggregates by CDW (aggregates of concrete waste) in the production of concretes. In this sense, the effects of this substitution on the workability and mechanical characteristics of the concretes produced, as well as the influence of the mixing method and the percentage of superplasticizer additive on the same characteristics were evaluated. The methodology basically consists in the production of seven different traits, which are references and different combinations of mixing method, aggregate substitutions and superplasticizer percentages. Specimens of these traces were molded for mechanical characterization. Workability parameters were also evaluated. It is concluded that the workability is strongly affected by the addition of CDW, but a good workability can be obtained with the use of superplasticizer additives. The mixing method did not change the results obtained for this property. The results also indicate that the compressive and tensile strengths are not negatively affected by the substitution of aggregates, as well as being not significantly affected by the presence of the percentages of superplasticizer used, nor by the mixing methods.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1518
Author(s):  
Antonio López-Uceda ◽  
Enrique Fernández-Ledesma ◽  
Lorenzo Salas-Morera ◽  
José Ramón Jiménez ◽  
David Suescum-Morales

Recycled aggregates (RA) from construction and demolition waste are an alternative to natural aggregates in the construction sector. They are usually classified according to their composition. The main constituent materials are separated into the following categories: unbound natural aggregates, ceramic particles, cementitious particles, bituminous materials, and other materials considered impurities, such as glass, plastic, wood, or gypsum. In this research, a large number of samples of RA were collected from three different recycling plants and their properties were studied. After that, 35 samples were selected randomly, and their RA constituents were separated under laboratory conditions. Cementitious particles were differentiated into two subcategories: masonry mortar and concrete particles. Subsequently, their physical–mechanical properties were measured. The statistical analysis carried out exhibited that the constituents had a statistically significant influence on the physical–mechanical properties studied. Specifically, masonry mortar particles had higher water absorption and worse mechanical properties than concrete and ceramic particles. Secondly, multiple regression models were performed to predict the physical–mechanical properties of RA from their composition since mean absolute percentage error (MAPE) ranged between 0.9% and 8.6%. The differentiation in the subcategories of concrete and masonry mortar particles in compositional testing is useful for predicting the physical–mechanical properties of RA.


2013 ◽  
Vol 690-693 ◽  
pp. 865-869 ◽  
Author(s):  
Marília Martinês de Camargo ◽  
Rosa Cristina Cecche Lintz ◽  
Luisa Andréia Gachet-Barbosa ◽  
Marta Siviero Guilherme Pires

The Construction is recognized as one of the most important activities for the economic and social development, and on the other hand, behaves also as a major generator of environmental impacts, either by consumption of natural resources, the modification of the landscape or the generation of construction and demolition waste (CDW). Investing in an implementation of managed clean and healthy in the area of CDW is essential for the environment and for the economy of the cities, who are spending less resources on the collection, cleaning of drains and treatment of diseases. Nowadays, the amount of waste generated is considered large, occupying much space in landfills, and its transportation, depending on the volume and weight, is quite expensive. Recycling and reuse of these wastes are extremely important to control and mitigate environmental problems, as well as produce various materials value-added. Over 90% of waste can be recycled, reused and transformed into aggregates with characteristics very similar to the original product, thus creating environmentally friendly products such as sand, gravel, pebbles. This research concerns the study of the properties of concrete containing CDW, aiming its use in the manufacture of concrete blocks to seal without structural function. Blocks have been molded with partial replacement of natural aggregates by recycled aggregates and later were performed tests of compressive strength in accordance with the standards to prove the technical feasibility of the material for the trait studied.


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.


2019 ◽  
Vol 22 ◽  
pp. 67-71
Author(s):  
Karel Mikulica ◽  
Iveta Hájková

In the future, it is planned to use up to 50% of construction and demolition waste (C&DW) for the production of new building structures. This leads us to think about how we can use recycled concrete aggregate (RCA) as a substitute for natural aggregate (NA) in concrete mixtures. This is why we compare the two typical representatives of recycled aggregates with a representative of natural aggregates. As a representative of recycled aggregates, we chose pure concrete recycled from the cutting of concrete and mixed recyclate from the demolition of the apartment building. As a representative of natural stone, we chose the extracted aggregate.


Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 40
Author(s):  
Miguel Bravo ◽  
António P. C. Duarte ◽  
Jorge de Brito ◽  
Luís Evangelista

This works intends to analyze, experimentally and numerically, the bond-slip behavior between steel and concrete made with recycled aggregates (RA) from construction and demolition waste (CDW) from several recycling plants in Portugal. Pull-out tests performed in concrete mixes with RA from CDW are described and the main results (bond strength, bond-slip curves and failure modes) are shown and discussed. Additionally, a comparison between experimental and analytical (using equations from the literature) results is made. Afterwards, finite element (FE) models using Abaqus are developed and compared with the experimental results. The interface behavior between steel and concrete follows that prescribed by the CEB-FIP Model Code and uses as input experimental results. After validation, the models show good results when extended to predict the bond-slip behavior of the remaining concrete mixes studied. It is generally concluded that, per each 10% of natural aggregates replaced with RA from CDW, the bond strength decreases in circa 3% (numerically) to 5% (experimentally). CEB-FIP Model Code equations are shown to be able to predict bond strength and, when used in FE models, to lead to accurate simulation of the bond-slip response of steel and concrete with RA from CDW: the average ratio between numerical and experimental bond strengths is 0.95. In the scope of the FE models developed, a simple equation to be used along with those prescribed by CEB-FIP, which accounts for fraction and ratio of aggregates replaced, is put forward, as a first approach, showing good results.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1700
Author(s):  
Glaydson Simões dos Reis ◽  
Marco Quattrone ◽  
Weslei Monteiro Ambrós ◽  
Bogdan Grigore Cazacliu ◽  
Carlos Hoffmann Sampaio

A literature review comprising 163 publications published over a period of 26 years from 1992 to 2018 is presented in this paper. This review discusses the generation and recycling of construction and demolition waste (CDW) as well as its main uses as raw materials for the construction engineering sector. This review pays attention to the use of CDW aggregates for sand, pavements/roads, bricks, ceramics, cementitious materials, and concrete productions, as well its uses as eco-friendly materials for water decontamination. The physical-chemical and mechanical characteristics of recycled aggregates play an important role in their correctly chosen applications. The results found in this literature survey allow us to conclude that recycled aggregates from CDW can be successfully used to produce construction materials with quality comparable to those produced with natural aggregates. We concluded that the use of CDWs as raw materials for manufacturing new construction materials is technically feasible, economical, and constitutes an environmentally friendly approach for a future construction and demolition waste management strategy.


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