Bibliometric Study of the Use of Recycled Aggregates in the Manufacturing of Precast Concrete

INCREaSE 2019 ◽  
2019 ◽  
pp. 964-980
Author(s):  
Zoraida Sánchez-Roldán ◽  
Gloria María Cuenca-Moyano ◽  
María Martín-Morales ◽  
Montserrat Zamorano
Keyword(s):  
Precast Concrete ◽  
Bibliometric Study ◽  
Recycled Aggregates

Structural Integrity Assessment of Precast Concrete Slabs Employing Conventional and Recycled Coarse Aggregates via Vibration Tests

2014 ◽  
Vol 600 ◽  
pp. 504-513 ◽  
Author(s):  
Roberto Leal Pimentel ◽  
Sandro Marden Torres ◽  
Enildo Tales Ferreira ◽  
Aluísio Braz de Melo
Keyword(s):  
Structural Integrity ◽  
Load Capacity ◽  
Precast Concrete ◽  
Damping Ratio ◽  
Limit State ◽  
Load Level ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Impact Excitation ◽  
Integrity Assessment

Precast slabs were tested, consisting of ceramic blocks supported by concrete ribs and with a concrete topping a few centimeters thick. These structures are very common in Brazil, being employed for the construction of houses and small buildings. In one of the tested slabs, recycled coarse aggregate was employed while conventional aggregate (granite gravels and quartz sand) was employed in the other tested slab. This study is part of a broader experimental programme which was designed to assess the applicability of concrete containing recycled aggregates as conventional aggregate replacement. In order to get insight into the structural behavior of slabs with recycled aggregates, the main focus of this paper is to assess the effect of structural load level on vibration parameters (Resonance Frequency, Damping Ratio and Transit Time). Full scale slab structural integrity was assessed by following changes in these parameters via a vibration (modal) test employing impact excitation. The structures were tested for several static load ratios (load to ultimate loading ratios (55%, 82% and 98%)). Visual inspection of induced cracking was also performed. The results obtained indicate a reduction of stiffness in both slabs up to 50% of the stiffness of the respective uncracked structure, which followed a similar trend despite the aggregate types. As for the damping ratios, the recycled aggregate containing slab showed lower values in comparison to the control slab with conventional aggregate. Whereas the former results might indicate similar load capacity, the latter, in principle, may have implications for the vibration serviceability limit state of structures. However, although structures with lower damping ratio can potentially present vibration problems, these studied elements are not often subjected to excessive vibration in its service life.

scholarly journals Upgrading the Quality of Recycled Aggregates from Construction and Demolition Waste by Using a Novel Brick Separation and Surface Treatment Method

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2893
Author(s):  
Kui Hu ◽  
Yujing Chen ◽  
Caihua Yu ◽  
Dong Xu ◽  
Shihao Cao ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Precast Concrete ◽  
Highway Construction ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Base Layer ◽  
Quality Level ◽  
Demolition Waste ◽  
Shape Characteristics

Mixed recycled aggregates (MRA) from construction and demolition waste (CDW) with high-purity and environmental performance are required for highway construction application in base layer and precast concrete curbs. The main problematic constituents that reduce the quality level of the recycled aggregates applications are brick components, flaky particles, and attached mortar, which make up a large proportion of CDW in some countries. This paper studies the potential of brick separation technology based on shape characteristics in order to increase the recycled concrete aggregates (RCA) purity for MRA quality improvement. MRA after purification was also processed with surface treatment experiment by rotating in a cylinder to improve the shape characteristics and to remove the attached mortar. The purity, strength property, densities, water absorption ratio, shape index, and mortar removal ratio of MRA were studied before and after the use of the brick separation and surface treatment proposed in this study. Finally, the recycled aggregates upgradation solution was adopted in a stationary recycling plant designed for a length of 113 km highway construction. The properties of CDW mixed concrete for precast curbs manufacturing were conducted. The results indicate that problematic fractions (brick components, particle shape, and surface weakness) in the MRA were significantly reduced by using brick separation and surface treatment solution. Above all, it is very important that the proposed brick separation method was verified to be practically adopted in CDW recycling plant for highway base layer construction and concrete curbs manufacturing at a low cost.

scholarly journals Recycled Precast Concrete Kerbs and Paving Blocks, a Technically Viable Option for Footways

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7007
Author(s):  
Andrés Juan-Valdés ◽  
Desirée Rodríguez-Robles ◽  
Julia García-González ◽  
María Isabel Sánchez de Rojas ◽  
Manuel Ignacio Guerra-Romero ◽  
...  
Keyword(s):  
Water Absorption ◽  
Circular Economy ◽  
Precast Concrete ◽  
Research Work ◽  
Lower Class ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Concrete Durability ◽  
Conventional Concrete

The linear economy paradigm in place to date has to be seriously challenged to give way to a new school of thought known as the circular economy. In this research work, precast kerbs and paving blocks made with recycled concrete (RACC-mixture) bearing 50 wt% mixed recycled aggregate (masonry content of 33%) and an eco-efficient cementitious material as 25 wt% conventional binder replacement were evaluated to assess their intrinsic potential to replace traditional raw materials, in keeping with circular economy criteria. Therefore, precast products were subjected to mechanical strength, durability and microstructure tests and were compared to conventional concrete units (CC-mixture and commercially available precast elements). Although a class demotion was observed for water absorption and some decreases in flexural strength (26%), splitting tensile strength (12.8%) and electrical resistivity (45%) and a lower class water absorption were registered, and the recycled mixture also exhibited a greater performance in terms of compressive strength (6%), a better abrasion resistance classification and a comparable porosity and microstructure, which ensures a good concrete durability. In any case, the results showed that precast pieces were European standard-compliant, thus supporting the viability of the mixed recycled aggregates and eco-efficient cementitious replacement in footways.

scholarly journals Paving with Precast Concrete Made with Recycled Mixed Ceramic Aggregates: A Viable Technical Option for the Valorization of Construction and Demolition Wastes (CDW)

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 24 ◽  
Author(s):  
Andrés Juan-Valdés ◽  
Julia García-González ◽  
Desirée Rodríguez-Robles ◽  
Manuel Guerra-Romero ◽  
Fernando López Gayarre ◽  
...  
Keyword(s):  
Precast Concrete ◽  
Recycled Concrete ◽  
The Other ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Mass Concrete ◽  
Conventional Concrete ◽  
Mixed Aggregates ◽  
Precast Elements ◽  
Mixed Ceramic

This research aimed to prove the feasibility of producing two types of precast elements widely used in construction, such as curbstones and paving blocks, using recycled concrete made with a 50% substitution of the natural gravel by recycled mixed aggregates with a significant ceramic content (>30%). In order to prove the quality of such mass concrete recycled precast elements, two different mixes were used: the first one was a conventional concrete mix provided by Prefabricados de Hormigón Pavimentos Páramo S.L., one of the collaborating companies in this study, and the other was a mixture in which wt 50% of the natural coarse aggregates were substituted for recycled mixed aggregates ceramic (RMAc). This recycled aggregate is a heterogeneous mixture of unbound aggregates, concrete, ceramic, etc., used as a secondary recycled aggregate and commonly produced in a lot of recycling plants in many European countries. This material was supplied by Tecnología y Reciclado S.L., the other collaborating company. Both mixtures were representative in order to establish the comparative behavior between them, taking into account that smaller percentages of replacement of the natural with recycled aggregates will also produce good results. This percentage of substitution represents a high saving of natural resources (gravel) and maintains a balanced behavior of the recycled concrete, so this new material can be considered to be a viable and reliable option for precast mass concrete paving elements. The characterization of the recycled precast elements, covering mechanical, microstructural, and durability properties, showed mostly similar behavior when compared to the analogous industrially-produced pieces made with conventional concrete.

scholarly journals Recycled Aggregates from Construction and Demolition Waste in the Manufacture of Urban Pavements

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6605
Author(s):  
Manuel Contreras-Llanes ◽  
Maximina Romero ◽  
Manuel Jesús Gázquez ◽  
Juan Pedro Bolívar
Keyword(s):  
Precast Concrete ◽  
Breaking Load ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Waste Streams ◽  
Demolition Waste ◽  
Class 1 ◽  
Natural Aggregates ◽  
Precast Elements ◽  
Concrete Elements

Construction and Demolition Waste (CDW) is among the largest waste streams in the world. Therefore, within the Circular Economy concept, there is a growing interest in its reuse. The purpose of this work was to study the use of recycled aggregates (RAs) obtained by a specific separation method from CDW, replacing natural aggregates (NAs) in the manufacture of precast concrete elements, such as kerbstones and paver blocks. The physical and technological properties of precast products formulated with RAs were analysed in accordance with current regulations, comparing them with those of commercial products manufactured with NAs. The results indicated that partial or total substitution of NAs by RAs increased the water absorption and apparent porosity values of the precast elements while reducing the bulk density and compressive strength. However, all units manufactured with RAs showed breaking load values higher than the minimum required by EN 1338 and, in some cases, slightly higher average tensile strength values than the reference material. In addition, some of the compositions including RAs gave rise to pieces that, according to their flexural strength, were classified as class 1 and marked S in accordance with EN 1340. According to abrasion resistance, in most cases, the precast elements are classified as Class 4 and I (≤20 mm). Finally, precast concrete produced from RAs satisfies the tolerance requirements for classification as class 3 (≤1.5 kg m−2). Therefore, it could be suitable for use in high pedestrian or traffic areas.

scholarly journals Industrial Low-Clinker Precast Elements Using Recycled Aggregates

2020 ◽  
Vol 10 (19) ◽  
pp. 6655
Author(s):  
Carlos Thomas ◽  
Ana I. Cimentada ◽  
Blas Cantero ◽  
Isabel F. Sáez del Bosque ◽  
Juan A. Polanco
Keyword(s):  
Mechanical Properties ◽  
Coarse Aggregate ◽  
Precast Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Slight Reduction ◽  
Construction And Demolition Wastes ◽  
Precast Elements ◽  
The Impact ◽  
Concrete Elements

Increasing amounts of sustainable concretes are being used as society becomes more aware of the environment. This paper attempts to evaluate the properties of precast concrete elements formed with recycled coarse aggregate and low clinker content cement using recycled additions. To this end, six different mix proportions were characterized: a reference concrete; 2 concretes with 25%wt. and 50%wt. substitution of coarse aggregate made using mixed construction and demolition wastes; and others with recycled cement with low clinker content. The compressive strength, the elastic modulus, and the durability indicator decrease with the proportions of recycled aggregate replacing aggregate, and it is accentuated with the incorporation of recycled cement. However, all the precast elements tested show good performance with slight reduction in the mechanical properties. To confirm the appropriate behaviour of New Jersey precast barriers, a test that simulated the impact of a vehicle was carried out.

scholarly journals PERFORMANCE ASSESSMENT OF A SELF-COMPACTING CONCRETE WITH COARSE AND FINE RECYCLED AGGREGATE

2020 ◽  
Author(s):  
Víctor Revilla-Cuesta ◽  
José Antonio Chica Paez ◽  
José Antonio De la Fuente Alonso ◽  
Estibaliz Briz Blanco ◽  
Jorge Hernández Bagages ◽  
...  
Keyword(s):  
Precast Concrete ◽  
Fine Fraction ◽  
Modern Society ◽  
Coarse Fraction ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Self Compacting Concrete ◽  
Limestone Filler ◽  
Hardened State ◽  
Concrete Elements

Environmental protection and more sustainable human activities are two of the main goals faced by modern society. The reuse of wastes, framed within these objectives, directly affects the construction sector. The use of residues enables to reduce the consumption of natural resources and CO2 emissions released into the atmosphere because of the extractive activity, as well as to reduce potential landfills, thus contributing to a circular economy. Accordingly, this paper explores the development of self-compacting concrete made from high-quality recycled aggregates, obtained from the crushing of precast concrete elements. The replacement rates of the natural aggregate by the recycled aggregate were 100% for the coarse fraction and 50% for the fine fraction. Its validity for structural use is analyzed, both fresh and hardened. In addition, the importance of the limestone filler in the fresh rheology of the mentioned concrete and its impact in the hardened state are also evaluated.

scholarly journals Fresh-State and Mechanical Properties of High-Performance Self-Compacting Concrete with Recycled Aggregates from the Precast Industry

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3565 ◽  
Author(s):  
Tiago Barroqueiro ◽  
Pedro R. da da Silva ◽  
Jorge de de Brito
Keyword(s):  
Mechanical Properties ◽  
Construction Industry ◽  
High Performance ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Recycled Aggregates ◽  
Self Compacting Concrete ◽  
Environmentally Sustainable ◽  
Sustainable Solutions ◽  
Fresh State

The urgent need to change the less positive impacts of the construction industry on the environment, and more specifically the production and use of concrete, is the main motivation for the research for more efficient and environmentally sustainable solutions. This paper presented the results of an experimental campaign whose ultimate goal was to produce high-performance self-compacting concrete (SCC) using recycled aggregates (RA) from the precast industry. The results of the fresh-state and mechanical properties tests performed on six concrete mixes (using RA from the precast industry) were presented. The first concrete mix is a reference mix using natural aggregates only (100% NA), and the remaining five mixes had various contents of fine (FRA) and coarse (CRA) recycled aggregates in concrete’s composition: (2) 25/25% (25% RA); (3) 50/50% (50% RA); (4) 100/100% (100% RA); (5) 0/100% (100% CRA); (6) 100/0% (100% FRA). The results showed that the high-performance concrete mixes with RA from the precast industry performed worse than the reference mix. However, taking into account all the mechanical properties studied, it can be concluded that RA from precast concrete elements are of very good quality and can be incorporated in the production of high-performance SCC. The potential demonstrated by the combined use of fine and coarse recycled aggregates was also emphasized. This type of work is expected to effectively contribute to raise awareness among the various players in the construction industry, particularly in the precast concrete industry, to the feasibility of using RA in significant quantities (notably coarse aggregates) and to the safety needed to assume structural functions, even for applications where high performance is required.

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