Quality Improvement of Recycled Aggregates from a Construction and Demolition Waste Recycling Pilot Plant

2012 ◽  
Vol 730-732 ◽  
pp. 630-635
Author(s):  
D. Algarvio ◽  
Maria Margarida Rolim Augusto Lima ◽  
M.L. Cunha
Keyword(s):  
Quality Improvement ◽  
Magnetic Separation ◽  
Pilot Plant ◽  
Waste Recycling ◽  
Separation Process ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Size Fractions ◽  
Cumulative Curves

The construction and demolition wastes (C&DW) frequently are abandoned in private properties, roads, and landfills or collected by non-licensed companies. In Portugal they are few recycling plants operating with this residue, and this work makes the bridge between the mechanical recycling process developed on semi-industrial scale, and the recycling products characterization process developed on laboratorial scale. The main goal of the present work is the quality improvement of the recycled aggregates produced by a construction and demolition waste recycling pilot plant with 50 ton/h located in Montemor-o-Novo. Process operations are the hammer mill comminution, magnetic separation and sieving (bar sieves: 0-4mm, 4-8mm and 8-12mm; and square sieves: 12-22mm, 22-31mm and above 31mm). In order to improve the magnetic separation process, several tests with different distances between the magnet and the conveyor belt were made (21-31cm). On the other hand, to improve the quality of the produced aggregates, the bar screen size fractions were analyzed, according to the Portuguese Standard (NP EN 933-1 2000). The most efficient distances for the magnetic separation process were identified as between 21 and 27cm, with efficiency between 85% and 90% respectively. According to the histograms, the more frequent red aggregate from 0-4mm size fraction are +0.425-0.850; +0.850-1.7 and +1.7-3.35. From the 4-8mm red aggregates, the more frequent size fractions are +4.75-6.7 and +6.7-9.95. Finally, from the 8-12mm red aggregates, the more frequent new size fractions are +6.7-9.50 and +9.50-13.20. Sieving results obtained from cumulative curves for red aggregate showed an decrease in the mass % amount for the size fractions: 0-4mm: 97%, 4-8mm:76% and 8-12mm: 56%. The results from cumulative curves for grey aggregate showed a light decreased in the amount mass % for the size fractions: 0-4mm: 90%, 4-8mm:56% and 8-12mm: 60%.

Microstructure of Concrete with Aggregates from Construction and Demolition Waste Recycling Plants

2015 ◽  
Vol 22 (1) ◽  
pp. 149-167 ◽  
Author(s):  
Miguel Bravo ◽  
António Santos Silva ◽  
Jorge de Brito ◽  
Luís Evangelista
Keyword(s):  
Water Absorption ◽  
Waste Recycling ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Absorption Test ◽  
Capillary Water ◽  
Demolition Waste ◽  
Capillary Water Absorption ◽  
Eds Analysis ◽  
Water Absorption Test

AbstractThis paper intends to analyze the microstructure of concrete with recycled aggregates (RA) from construction and demolition waste from various Portuguese recycling plants. To that effect, several scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses were performed. Various concrete mixes were evaluated in order to analyze the influence of the RA’s collection point and consequently of their composition on the mixes’ characteristics. Afterward all the mixes were subjected to the capillary water absorption test in order to quantitatively evaluate their porosity. Results from the SEM/EDS analysis were compared with those from capillary water absorption test. The SEM/EDS analysis showed that the bond capacity of aggregates to the new cement paste is greatly influenced by the RA’s nature. On the other hand, there was an increase in porosity with the incorporation of RA.

CONCRETO PERMEÁVEL COM AGREGADO DA RECICLAGEM DE RESÍDUOS DA CONSTRUÇÃO E DEMOLIÇÃO: REVISÃO BIBLIOGRÁFICA / PERMEABLE CONCRETE WITH AGGREGATE FROM CONSTRUCTION AND DEMOLITION WASTE RECYCLING: LITERATURE REVIEW

2020 ◽  
Vol 6 (9) ◽  
pp. 73169-73180
Author(s):  
Kelly Patrícia Torres Vieira Brasileiro ◽  
Bacus de Oliveira Nahime ◽  
Michell Macedo Alves ◽  
Pâmela Millena Kunan ◽  
Vitor Alvares ◽  
...  
Keyword(s):  
Literature Review ◽  
Waste Recycling ◽  
Construction And Demolition Waste ◽  
Demolition Waste

scholarly journals Application of Construction and Demolition Waste in Civil Construction in the Brazilian Amazon—Case Study of the City of Rio Branco

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2247
Author(s):  
Fernando da Silva Souza ◽  
José Maria Franco de Carvalho ◽  
Gabriela Grotti Silveira ◽  
Vitória Cordeiro Araújo ◽  
Ricardo André Fiorotti Peixoto
Keyword(s):  
Mechanical Strength ◽  
Raw Materials ◽  
Amazon Region ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Federal State ◽  
Construction Sites ◽  
Demolition Waste ◽  
Conventional Concrete ◽  
Initial Adhesion

The lack of usable aggregates for civil construction in Rio Branco (capital of Acre, a Federal State in the Amazon region) makes the production and use of recycled aggregates from construction and demolition waste (CDW) an alternative of great interest. In this study, a comprehensive characterization of CDW collected from 24 construction sites of six building types and three different construction phases (structures, masonry, and finishing) was carried out. The fine and coarse recycled aggregates were produced and evaluated in 10 different compositions. The aggregates’ performance was evaluated in four mixtures designed for laying and coating mortars with a total replacement of conventional aggregates and a mixture designed for a C25 concrete with 50% and 100% replacement of conventional aggregates. CDW mortars showed lower densities and greater water retention, initial adhesion, and mechanical strength than conventional mortars. CDW concretes presented lower densities and greater resistance to chloride penetration than conventional concrete, with a small mechanical strength reduction. The recycled CDW aggregates proved to be technologically feasible for safe application in mortars and concrete; for this reason, it is believed that the alternative and proposed methodology is of great interest to the Amazonian construction industry, considering the high costs of raw materials and the need for defining and consolidating a sustainable development model for the Amazon region.

Financial and economic evaluation of construction and demolition waste recycling in Hanoi, Vietnam

2021 ◽  
Vol 131 ◽  
pp. 294-304
Author(s):  
Ngoc Han Hoang ◽  
Tomonori Ishigaki ◽  
Rieko Kubota ◽  
Ton Kien Tong ◽  
Trung Thang Nguyen ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
Waste Recycling ◽  
Construction And Demolition Waste ◽  
Demolition Waste

Concrete Production of Hot Asphalt Using Recycled Aggregates CDW

2016 ◽  
Vol 881 ◽  
pp. 346-350 ◽  
Author(s):  
Luzana Leite Brasileiro ◽  
Fátima Maria de Souza Pereira ◽  
Pablo de Abreu Vieira ◽  
José Milton Elias de Matos
Keyword(s):  
Solid Waste ◽  
National Policy ◽  
Mechanical Tests ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Final Destination ◽  
Natural Aggregate ◽  
Concrete Production

Every year, there is a considerable increase in the exploitation of deposits to supply the market for aggregates. On the other hand, so does the production of solid waste from construction and demolition waste (CDW). In 2010 Brazil approved the PNRS (National Policy on Solid Waste), which sets out how the country should have their waste, encouraging recycling and sustainability. As an alternative to the above problem, this paper aims to investigate the feasibility of partial and total replacement of the asphalt concrete aggregates by recycled aggregates from CDW in order to reduce the environmental impacts caused by the operation of quarries and give an adequate final destination the residue produced by man in construction. Were carried out five (05) projects mixture of: the first (parameter of our research) used only natural aggregates (0% CDW) in the second, third and fourth replaced 25%, 50% and 75% respectively of natural aggregate by the recycled aggregate and the fifth and last, used only recycled aggregates (100% CDW). They carried out the characterization of the aggregates by means of physico-chemical and mechanical, analyzing them with reference based on specific standards paving. For mixtures, they calculated the volumetric parameters and performed mechanical tests of tensile strength and stability. The results indicate that the recycled aggregate, in a defined proportion, can replace the natural aggregate in the flexible pavements

Environmental assessment of construction and demolition waste recycling in Bolivia: Focus on transportation distances and selective collection rates

2021 ◽  
pp. 0734242X2110291
Author(s):  
Navarro Ferronato ◽  
Gabriela Edith Guisbert Lizarazu ◽  
Marcelo Antonio Gorritty Portillo ◽  
Luca Moresco ◽  
Fabio Conti ◽  
...  
Keyword(s):  
Developing Countries ◽  
Environmental Impacts ◽  
Waste Recycling ◽  
Construction And Demolition Waste ◽  
Primary Data ◽  
Demolition Waste ◽  
Collection Rate ◽  
Material Recycling ◽  
Material Recovery ◽  
Selective Collection

Construction and demolition waste (CDW) management in developing countries is a global concern. The analysis of scenarios and the implementation of life cycle assessment (LCA) support decision-makers in introducing integrated CDW management systems. This paper introduces the application of an LCA in La Paz (Bolivia), where CDW is mainly dumped in open areas. The aim of the research is to evaluate the benefits of inert CDW recycling in function of the selective collection rate, defined as the amount of waste (%wt.) sorted at the source in relation to the total waste amount produced, and the distances from the CDW generation to the material recycling facility. The outcomes of the research suggest that increasing the selective collection rates (5% to 99%) spread the importance of transportation distances planning since it affects the magnitude of the environmental impacts (1.05 tCO2-eq to 20.7 tCO2-eq per km traveled). Transportation limits have been found to be lower than about 40 km in order to make recycling beneficial for all environmental impacts and for all selective collection rate, with the eutrophication potential as the limiting indicator. The theoretical analysis suggests implementing LCA with primary data and involving statistics related to the transportation of virgin materials avoided thanks to recycling. The outcomes of the research support the implementation of CDW recycling in developing countries since it has been found that material recovery is always beneficial.

scholarly journals Catalogue of Pavements with Recycled Aggregates from Construction and Demolition Waste

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1282 ◽  
Author(s):  
Auxi Barbudo ◽  
José Ramón Jiménez ◽  
Jesús Ayuso ◽  
Adela Pérez Galvín ◽  
Francisco Agrela
Keyword(s):  
Point Of View ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Technical Application ◽  
Technical Specifications ◽  
Lack Of Knowledge

Construction and Demolition Waste come from debris generated during construction, renovation and demolition of buildings, roads, and bridges. Recycling and reuse are essential in terms of sustainability, mainly from an environmental point of view. Although the recommendation of the use of these recycled aggregates is currently included in some technical specifications, its use is still not widespread due mainly to the lack of knowledge on their technical application. This work is a compilation of the recommendations proposed in the “Catalogue of road pavements with recycled aggregates”, supported by the construction of experimental stretches. It proposes different structural sections for road pavements by using recycled aggregates.

scholarly journals Effects of Recycled Aggregate Resin (RAR) in Concrete Material

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Sharifah Salwa Mohd Zuki ◽  
◽  
Shahiron Shahidan ◽  
Shivaraj Subramaniam ◽  
◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Engineering Properties ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Demolition Waste ◽  
Split Tensile Strength ◽  
Close Proximity

This paper discussed the recycled aggregates produced from construction and demolition waste and their utilization in concrete construction. Along with a brief overview of the engineering properties of recycled aggregates, the paper also summarizes the effect and use of recycled aggregates on the properties of fresh and hardened concrete. The recycled aggregates were treated with epoxy resin to reduce the water absorptions with different percentages of resin such as 0%, 25%, 50%, 75%, and 100%. Epoxy resin is widely used in recent years owing to the enhancing of mechanical and durability of the concrete. This research also showed, recycled aggregate concrete are close proximity to normal concrete in terms of split tensile strength, compression strength and wet density. The low usage of resin was obtained good strength concrete compared to high percentage contained treated aggregates due to low bonding between material.

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