scholarly journals Feasible Use of Recycled Concrete Aggregates with Alumina Waste in Road Construction

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1466
Author(s):  
Manuel Cabrera ◽  
Mónica López-Alonso ◽  
Laura Garach ◽  
Javier Alegre ◽  
Javier Ordoñez ◽  
...  
Keyword(s):  
Second Life ◽  
Road Construction ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
The Road ◽  
Road Pavement ◽  
Pavement Base ◽  
By Products

The management of different industrial by-products, such as recycled aggregates from construction and demolition waste and alumina by-products, as well as the reduction of landfill deposits by incorporating these products in a second life cycle, were the focus of this work. The aim of this study was to demonstrate the technical viability of using these waste and by-product as a material for road pavement base layers. For this purpose, a real-scale application was carried out, and the behavior of three types of materials, applied on a section of an experimental road under real vehicle traffic conditions, was studied and compared. Three materials were used in these sections applied in the road sub-bases. First, a control material composed of a type of artificial gravel was used to be compared with the rest of materials; the second material was composed of recycled aggregates, and the third was composed of a mix of recycled aggregates and alumina waste. The results concluded that the effectiveness of the sections built using recycled aggregates and alumina waste was very positive and similar those constructed using natural aggregates.

Use of soils and recycled industrial products treated with water glass in the road pavement base courses

2021 ◽  
Vol 2021 ◽  
pp. 86-93
Author(s):  
Anatolii Mudrychenko ◽  
◽  
Andrii Hrinchuk ◽  
Ivan Balashov ◽  
Sergey Illyasch ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Sodium Silicate ◽  
Water Glass ◽  
Water Solution ◽  
Road Construction ◽  
The Road ◽  
Road Pavement ◽  
Stone Materials ◽  
Pavement Base ◽  
Local Materials

Introduction. Growing volumes of road construction increase the need to expand and rationally use of raw materials. The need for stone materials can be solved through the wide spread using of local materials, recycled products of industry in the pavement base courses and decreasing the use of natural construction materials by replacing them with alternatives, including soils, slag materials that are metallurgical industry wastes. Experience of ferrous metallurgy slag usage has been accumulated in the road industry of Ukraine. Their usage makes it possible to extend the construction season, increases the strength and reliability of road structures due to their physical and mechanical properties, significantly reduces the road pavement energy consumption, simplifying the technology of works and the estimated cost of road construction. It was determined that the layers of pavement made from blast furnace slag have a high bearing capacity. Slag structures in 5–10 years of hardening are not inferior to, and in 10–20 years surpass cement structures on durability and deformation resistance. However, there is an urgent need to provide strength and open road traffic on the already built road section in a shortest possible term, so there is a need to accelerate the activation of the slow-setting binder. Therefore water glass (water solution of sodium silicate) is used.Purpose. The purpose of the work is to study the feasibility of using the soils and recycled industry products treated with water glass in the road pavement base courses.Materials and methods. Experimental tests of soils and blast furnace slags treated with water glass with different content of water solution of sodium silicate were performed.Results. The feasibility of using the asphalt concrete mixtures on the basis of soils and recycled products of industry treated with water glass in the pavement base courses is determined. Recommendations regarding technological parameters of preparation, transportation, laying and compaction of such mixes are given.Conclusions. Performed studies have shown that the physical and mechanical parameters of soils and blast furnace slags treated with water glass meet the requirements of current regulations of Ukraine. The advantages of use are noted, namely: the possibility of replacement of traditional stone materials by the local materials and recycled products of industry, reducing the transport component in the cost of construction. The obtained results indicate the feasibility of using the soils and recycled products of industry treated with water glass in the road construction.Keywords: soils, recycled products of industry, graded blast furnace slag, water solution of sodium silicate, water glass

scholarly journals Comparative study of the influence of three types of fibre in the shrinkage of recycled mortar

2018 ◽  
Vol 68 (332) ◽  
pp. 168 ◽  
Author(s):  
P. Saiz-Martínez ◽  
D. Ferrández-Vega ◽  
C. Morón-Fernández ◽  
A. Payán de Tejada-Alonso
Keyword(s):  
Negative Impact ◽  
Polypropylene Fiber ◽  
Capacitive Sensor ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Moisture Loss ◽  
Recycled Aggregates ◽  
Fiber Types ◽  
Demolition Waste ◽  
Recycled Concrete Aggregates

Construction and demolition waste can be used as a substitution of natural aggregate in mortar and concrete elaboration. A poorer quality of recycled aggregates generally has negative impact on mortar properties. Shrinkage is one of the properties that experiences worse outcome due to the higher absorption of recycled aggregates. This research evaluates the potential shrinkage of mortars elaborated with recycled concrete aggregates both with and without fibres addition, as well as the relation between moisture loss and shrinkage caused by mortar drying process using a capacitive sensor of the authors’ own design. Two different mortar dosages 1:3 and 1:4 and three fiber types: polypropylene fiber, fiberglass and steel fiber, in different proportions were used. Obtained results show that the use of polypropylene fiber improves the recycled mortars performance against shrinkage in 0.2%. Moreover, a clear relation between dry shrinkage and moisture loss was observed.

scholarly journals Laboratory Evaluation of Hot Asphalt Concrete Properties with Cuban Recycled Concrete Aggregates

2018 ◽  
Vol 10 (8) ◽  
pp. 2590 ◽  
Author(s):  
Debora Acosta Alvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio Tenza-Abril
Keyword(s):  
Asphalt Concrete ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Demolition Waste ◽  
Aggregate Fraction

Recycled Aggregates (RA) from construction and demolition waste (CDW) are a technically viable alternative to manufacture of asphalt concrete (AC). The main objective of this work is to evaluate the properties of hot asphalt mixtures that have been manufactured with different sources of CDW (material from concrete test specimens, material from the demolition of sidewalks and waste from prefabrication plants) from Cuba. Dense asphalt mixtures were manufactured with a maximum aggregate size of 19 mm, partially replacing (40%) the natural aggregate fraction measured between 5 mm and 10 mm with three types of RA from Cuba. Marshall specimens were manufactured to determine the main properties of the AC in terms of density, voids, stability and deformation. Additionally, the stiffness modulus of the AC was evaluated at 7 °C, 25 °C and 50 °C. The results corroborate the potential for using these sources of CDW from Cuba as a RA in asphalt concrete, thereby contributing an important environmental and economic benefit.

scholarly journals Performance Evaluation of Recycled Asphalt Mixtures Containing Construction and Demolition Waste Applicated as Pavement Base

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Le Ding ◽  
Junhui Zhang ◽  
Bowen Feng ◽  
Cheng Li
Keyword(s):  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Uniaxial Compression Test ◽  
High Temperature Stability ◽  
Demolition Waste ◽  
Recycled Asphalt ◽  
Freeze Thaw ◽  
Splitting Test ◽  
Marshall Test ◽  
Pavement Base

Construction and demolition waste contain large amount of concrete and bricks. To identify its feasibility of applying in asphalt stabilized gravel mixtures as pavement base, this paper carried out researches on properties of recycled asphalt mixture (RAM) by laboratory testing, under different contents of recycled aggregates (RA) and proportions of bricks to concrete. First, the basic physical properties of each component of the RAM were determined. According to the actual screening passing rate, the Bailey method was used to design and verify the grading of RAM, and then initial asphalt content was estimated. The stability, flow value, voidage, and bulk density were obtained by Marshall Test, and the optimal asphalt-aggregate ratios were determined under different RA contents and proportion of bricks to concrete. Subsequently, the uniaxial compression test, splitting tensile test, immersion Marshall test, freeze-thaw splitting test, and Hamburg rutting test were performed to investigate mechanical properties, water stability, and high-temperature stability of RAM. The results shows that as the content of RA increases from 0% to 100%, the corresponding compressive strength, resilient modulus, and splitting tensile strength all decrease; the same change trend is presented in the residual stability and freeze-thaw splitting test strength ratio and rutting depth. According to the requirement of pavement base of high-grade roads in China’s standards, the recommended RA content and proportion of bricks to concrete were proposed for the design RAM.

scholarly journals Complete Real-Scale Application of Recycled Aggregates in a Port Loading Platform in Huelva, Spain

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2651
Author(s):  
Francisco Agrela ◽  
Francisco González-Gallardo ◽  
Julia Rosales ◽  
Javier Tavira ◽  
Jesús Ayuso ◽  
...  
Keyword(s):  
Civil Engineering ◽  
Recycled Concrete ◽  
Environmental Benefits ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Base Layer ◽  
Recycling Rate ◽  
Demolition Waste ◽  
Technical Requirements ◽  
Real Scale

The application of recycled aggregates (RA) from construction and demolition waste and crushed concrete blocks is a very important challenge for the coming years from the environmental point of view, in order to reduce the exploitation of natural resources. In Spain, the use of these recycled materials in the construction of road bases and sub-bases is growing significantly. However, presently, there are few studies focused on the properties and behavior of RA in civil works such as road sections or seaport platforms. In this work, two types of RA were studied and used in a complete real-scale application. Firstly, recycled concrete aggregates (RCA) were applied in the granular base layer under bituminous superficial layers, and secondly mixed recycled aggregates (MRA) which contain a mix of ceramic, asphalt, and concrete particles were applied in the granular subbase layer, under the base layer made with RCA. Both RA were applied in a port loading platform in Huelva, applying a 100% recycling rate. This civil engineering work complied with the technical requirements of the current Spanish legislation required for the use of conventional aggregates. The environmental benefits of this work have been very relevant, and it should encourage the application of MRA and RCA in civil engineering works such as port platforms in a much more extended way. This is the first and documented real-scale application of RA to completely build the base and sub-base of a platform in the Huelva Port, Spain, replacing 100% of natural aggregates with recycled ones.

Production of upgraded recycled aggregates from construction and demolition waste for replacement of primary sand in cement mortars

2020 ◽  
Author(s):  
Michael Galetakis ◽  
Athanasia Soultana ◽  
Theodoros Daskalakis
Keyword(s):  
Water Absorption ◽  
Cement Paste ◽  
Cement Mortar ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Cement Mortars ◽  
Limestone Sand ◽  
Crushed Limestone

<p>Waste concrete is the most predominant constituent material among construction and demolition waste. Recycling of this material could minimize landfilled waste and mineral resources depletion. This study investigates, in laboratory scale, the production of upgraded recycled concrete aggregates, suitable for the replacement of primary (crushed limestone sand) used in cement mortars, by means of selective crushing and autogenous grinding. These particle size reduction techniques, compared to traditional crushing/grinding, have the potential to remove the brittle cement paste from the aggregates, thus significantly improving their quality. The granulometry, the density, the water absorption (EN 13755) and the flow coefficient (EN 933-6) of the produced upgraded sand was determined and compared to crushed limestone sand. Subsequently, cement mortar specimens were manufactured using upgraded aggregates for total replacement of crushed limestone sand. Specimens were tested for their compressive and flexural strength (EN 196-1), density and water absorption. Results indicated that the upgraded recycled sand produced through the selective crushing and autogenous grinding processes had improved properties compared to the one produced by conventional crushing processes (flexural and compressive strength of cement mortar specimens were increased by 29% and 7%, respectively). However, the quality of the upgraded sand is lower than that of the primary crushed limestone. To further explore the issue, it is planned to investigate in more detail the process of autogenous grinding and to investigate the use of other selective aggregate-cement paste liberation technologies.</p>

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 Development of Concrete Incorporating Recycled Aggregates, Hydrated Lime and Natural Volcanic Pozzolan

2021 ◽  
Vol 6 (11) ◽  
pp. 155
Author(s):  
Natividad Garcia-Troncoso ◽  
Bowen Xu ◽  
Wilhenn Probst-Pesantez
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Demolition Waste ◽  
Crushed Concrete ◽  
Natural Pozzolana ◽  
Concrete Materials

Recycling of construction and demolition waste is a central point of discussion throughout the world. The application of recycled concrete as partial replacement of mineral aggregates in concrete mixes is one of the alternatives in the reduction of pollution and savings in carbon emissions. The combined influence of the recycled crushed concrete, lime, and natural pozzolana on the mechanical and sustainable properties of concrete materials is firstly proposed in this study. In this research, unconventional construction materials are employed to produce concrete: the recycled crushed concrete is used as coarse aggregate, while lime and natural pozzolana are used as a partial replacement for cement. Substitutions of 10%, 20%, 50% of gravel are made with recycled aggregates, and 2%, 5%, 10% of cement with lime and natural pozzolan. Tests on the fresh and hardened properties, destructive (compressive strength) and non-destructive tests (sclerometer rebound and ultrasound) of mixtures are carried out. It is shown that the use of recycled materials can provide an increase in compressive strength of up to 34% with respect to conventional concrete. Life cycle cost and sustainability assessments indicate that concrete materials incorporating recycled aggregate possess good economic and environmental impacts.

scholarly journals Concrete-Based and Mixed Waste Aggregates in Rendering Mortars

2020 ◽  
Author(s):  
Cinthia Maia Pederneiras
Keyword(s):  
Mechanical Performance ◽  
Ceramic Materials ◽  
Cementitious Materials ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Demolition Waste ◽  
Recycled Concrete Aggregates ◽  
Mixed Recycled Aggregates

The construction industry is considered the biggest waste producer in Europe. In order to encourage recycling, European Parliament decreed through the Waste Framework Directive 2008/98/EC, that at least 70% of construction and demolition waste should be recycled by 2020. From recycling plants, three types of recycled aggregates are produced. Recycled Concrete Aggregate, mainly from cementitious waste, as such as concrete and mortars residues; Recycled Masonry Aggregates mainly composed by recycled ceramic materials, as such as tiles and bricks residues; Mixed Recycled Aggregates based on rubble residues, from heterogenous materials waste. This research evaluated the technical feasibility of rendering mortars with Recycled Concrete Aggregates and Mixed Recycled Aggregates, in different volume incorporation of 0%, 20%, 50% and 100%. The experimental programme comprised an analyse of the fresh and hardened properties, regarding the water and mechanical behaviour of the mortars. From the results, it was noticed that the modified mortars presented a reduction in the modulus of elasticity, which its correlated to a less susceptibility to cracking. Regarding mechanical performance, the modified mortars obtained reduction of the flexural and compressive strength over time. However, it was not a significant harmful criterion. Therefore, the incorporation of recycled aggregates in cementitious materials is considered a technical and sustainable solution.

scholarly journals Recycling construction and demolition wastes within hydraulically bound mixtures for road pavements

2021 ◽  
Author(s):  
Marco Pasetto ◽  
Andrea Baliello ◽  
Giovanni Giacomello ◽  
Emiliano Pasquini
Keyword(s):  
Construction Industry ◽  
Environmental Sustainability ◽  
Road Construction ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
The Road ◽  
Construction And Demolition Wastes ◽  
European Standards ◽  
Water Contents ◽  
Mineral Aggregates

The recycling of Construction and Demolition Waste (CDW) is an actual challenge regarding the construction industry because of the increasing volumes worldwide produced and the related environmental impacts. In this regard, a suitable application can be developed in the road construction field, in particular for the production of hydraulically bound mixtures for road subbase and foundation layers. In this sense, the reuse of CDW can strongly enhance the environmental sustainability of road construction thanks to the achievable savings of natural resources such as the mineral aggregates obtained from quarry operations. Indeed, the utilization of a CDW as aggregate must ensure the production of mixtures with adequate mechanical and environmental characteristics. Therefore, the herein paper presents the results of an experimental characterization aimed at assessing the suitability of CDW for the production of hydraulically bound mixtures for road pavements. In particular, the main mechanical properties of some mixtures including different percentages and gradations of CDW were analysed and compared with the main technical prescriptions and classification criteria indicated by the reference European standards. Basic properties and production processes of the CDW materials were also studied to determine their effects on the optimum binder and water contents of the mixtures. The research clearly demonstrated that the use of a preliminary-washed CDW coarse aggregate was able to enhance the overall structural properties and the water resistance of mixtures.

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