On the Possibility of Using Recycled Mixed Aggregates and GICC Thermal Plant Wastes in Non-Structural Concrete Elements

Industrial wastes are often used as aggregate in concrete production to promote a more sustainable construction and to reduce production costs. This article presents the results of an experimental campaign on the influence of replacing natural aggregate with several construction and demolition wastes (C&DW) as recycled aggregate, as well as the use of fly ash and slag, wastes produced in Gas Incinerator Combined Cycle (GICC) thermal power plants, in the mix design of non-structural concrete. Different percentages of natural aggregates were substituted with recycled aggregates either coming from construction and demolition wastes, or from the coarse fraction of the slags from thermic plants in the manufacture of concrete. The mechanical properties, capillary water absorption, density, carbonation, chloride ingress and sulphate resistance have been tested. The results show a decrease in properties when C&DW are used. Fine fraction of slag and fly ash has an important advantage, and can even improve the long term properties of concrete prepared with natural aggregates. Coarse fraction of slag as a recycled aggregate generally improves most of the properties of manufactured concretes.

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Construction and Demolition Waste As Recycled Aggregate for Environmentally-Friendly Concrete Paving.

10.21203/rs.3.rs-396080/v1 ◽

2021 ◽

Author(s):

Manuel Contreras Llanes ◽

Maximina Romero Pérez ◽

Manuel Jesús Gázquez González ◽

Juan Pedro Bolívar Raya

Keyword(s):

Tensile Strength ◽

Reference Sample ◽

Production Costs ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Demolition Waste ◽

Natural Sand ◽

Natural Aggregates ◽

Sand And Gravel

Abstract Recycled aggregates (RA) from construction and demolition waste (CDW) instead of natural aggregates (NA) was analysed in the manufacture of new eco-friendly concrete. Fine (FRA) and coarse (CRA) recycled aggregates were used in different percentages as substitutes of natural sand and gravel, respectively. The results revealed that the use of RA in percentages of up to 50 wt.% are feasible. Additionally, RA were used to produce paving blocks in accordance with industrial requirements. Thus, values of water absorption lesser than 6% and tensile strength upper than 3.6 MPa were obtained, which are similar to those of a reference sample. These results were achieved by reducing the incorporation of cement, thereby saving production costs and minimizing environmental impact.

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Mechanical Properties of Concrete Using Recycled Aggregates Obtained from Old Paving Stones

Sustainability ◽

10.3390/su13063044 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3044

Author(s):

Ana María Bravo-German ◽

Iván Daniel Bravo-Gómez ◽

Jaime A. Mesa ◽

Aníbal Maury-Ramírez

Keyword(s):

Mechanical Properties ◽

Environmental Impacts ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Demolition Waste ◽

Concrete Production ◽

Aggregate Fractions ◽

Increasing Demand ◽

Natural Aggregates

Nowadays, construction, maintenance, reparation, rehabilitation, retrofitting, and demolition from infrastructure and buildings generate large amounts of urban waste, which usually are inadequately disposed due to high costs and technical limitations. On the other hand, the increasing demand for natural aggregates for concrete production seriously affects mountains and rivers as they are the source of these nonrenewable goods. Consequently, the recycling of aggregates for concrete is gaining attention worldwide as an alternative to reduce the environmental impacts caused by the extraction of nonrenewable goods and disposal of construction and demolition waste (C&DW). Therefore, this article describes the effect on the mechanical properties of new concrete using recycled aggregates obtained from old paving stones. Results show that replacing 50% by weight of the fine and coarse aggregate fractions in concrete with recycled aggregate does not meaningfully affect its mechanical behavior, making the use of recycled aggregates in new precast paving stones possible. Therefore, the latter can reduce environmental impacts and costs for developing infrastructure and building projects.

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CONSTRUCTION POTENTIAL OF RECYCLED MASONRY FOR LIGHTWEIGHT CONCRETE

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2015.80 ◽

2015 ◽

Vol 2 (1) ◽

Author(s):

Daniela Ionescu ◽

Bandita Mainali ◽

Joe Petrolito ◽

Haider Al Abadi ◽

Simon Davies ◽

...

Keyword(s):

Lightweight Concrete ◽

Raw Materials ◽

Normal Weight ◽

Production Costs ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Building Industry ◽

Lightweight Aggregates ◽

Natural Aggregates ◽

Recycled Masonry

A sustainable and developing building industry requires large quantities of raw materials such as aggregates and crushed rocks. However, sourcing natural aggregates is becoming more problematic due to environmental impacts. Hence, the use of secondary materials, such as recycled aggregate can reduce the amount of natural aggregates required. Lightweight concrete is frequently used by the building industry, and it is commonly produced with natural lightweight aggregates such as scoria, which results in high production costs. Preliminary tests on recycled aggregates showed that recycled masonry has a similar specific gravity as scoria and relatively good strength. Hence, crushed masonry can be used to replace natural lightweight aggregates. This paper discusses the use of partial or total replacement of normal-weight aggregates with recycled lightweight aggregates, and its effects on the strength and elastic properties of concrete. It is shown that concrete mixes with recycled aggregates generate comparable results to mixes with scoria, but at lower production costs.

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Construction and demolition waste as recycled aggregate for environmentally friendly concrete paving

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15849-4 ◽

2021 ◽

Author(s):

Manuel Contreras Llanes ◽

Maximina Romero Pérez ◽

Manuel Jesús Gázquez González ◽

Juan Pedro Bolívar Raya

Keyword(s):

Reference Sample ◽

Production Costs ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Demolition Waste ◽

Natural Sand ◽

Limit Values ◽

Natural Aggregates ◽

Sand And Gravel

AbstractRecycled aggregates (RA) from construction and demolition waste (CDW) instead of natural aggregates (NA) were analysed in the manufacture of new eco-friendly concrete. Fine (FRA) and coarse (CRA) recycled aggregates were used in different percentages as substitutes of natural sand and gravel, respectively. The results revealed that the use of RA in percentages of up to 50 wt.% is feasible. Additionally, RA were used to produce paving blocks in accordance with industrial requirements. Thus, values of water absorption lesser than 6.0% and tensile strength upper than 3.6 MPa were obtained, which are similar to those of a reference sample and within the limit values established by the regulations. These results were achieved by reducing the incorporation of cement, thereby saving production costs and minimizing environmental impact.

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Effect of Mineral Admixtures on the Performance of Low-Quality Recycled Aggregate Concrete

Crystals ◽

10.3390/cryst11060596 ◽

2021 ◽

Vol 11 (6) ◽

pp. 596

Author(s):

Yasuhiro Dosho

Keyword(s):

Blast Furnace ◽

Fly Ash ◽

Blast Furnace Slag ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Mineral Admixtures ◽

Structural Concrete ◽

Aggregate Concrete ◽

Granulated Blast Furnace Slag ◽

Furnace Slag

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.

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Concrete Production of Hot Asphalt Using Recycled Aggregates CDW

Materials Science Forum ◽

10.4028/www.scientific.net/msf.881.346 ◽

2016 ◽

Vol 881 ◽

pp. 346-350 ◽

Cited By ~ 2

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

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An old bridge transformed into a new one: possible, recommendable?

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.0950 ◽

2019 ◽

Author(s):

Diego Carro-López ◽

Ignasi Fernandez ◽

Natalie Williams Portal

Keyword(s):

Environmental Issues ◽

Quality Standards ◽

Structural Effect ◽

Coarse Fraction ◽

Concrete Bridges ◽

Recycled Aggregates ◽

Structural Elements ◽

The Past ◽

Reinforced Concrete Bridges ◽

Natural Aggregates

<p>There is an extensive network of reinforced concrete bridges that give service to roads, highways and railways. These structures where constructed with quality standards of the past, and they suffer of severe problems. Now we consider the idea of substituting them with structural elements with much longer service life. However, there is an important question to be addressed in this area: what to do with the existing infrastructure that would be demolished. Even more if we consider environmental issues.</p><p>One good example of this recurrent problem could be found in the case of the Gullspång bridge (Sweden). It was constructed in 1935 and it was severely damaged with corrosion. The administration decided in the 2016 that no further repair would be done and that the bridge would be demolished and a new erected in substitution. A fraction of the concrete from the old bridge was crushed and processed to produce new aggregate. With this aggregate, using the coarse fraction, it was analyzed the structural effect of replacing natural aggregates with these recycled aggregates. The performance of the new structural elements was positive, and it seems that a high percentage of the natural aggregates could be replaced with recycled ones.</p>

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Mortars with CDW Recycled Aggregates Submitted to High Levels of CO2

Infrastructures ◽

10.3390/infrastructures6110159 ◽

2021 ◽

Vol 6 (11) ◽

pp. 159

Author(s):

Ricardo Infante Gomes ◽

David Bastos ◽

Catarina Brazão Farinha ◽

Cinthia Maia Pederneiras ◽

Rosário Veiga ◽

...

Keyword(s):

Large Scale ◽

Mechanical Performance ◽

Construction Materials ◽

Environmental Benefits ◽

Recycled Aggregates ◽

Construction And Demolition Wastes ◽

Short Period ◽

Natural Aggregates ◽

Cement Factories ◽

Made In

Construction and demolition wastes (CDW) are generated at a large scale and have a diversified potential in the construction sector. The replacement of natural aggregates (NA) with CDW recycled aggregates (RA) in construction materials, such as mortars, has several environmental benefits, such as the reduction in the natural resources used in these products and simultaneous prevention of waste landfill. Complementarily, CDW have the potential to capture CO2 since some of their components may carbonate, which also contributes to a decrease in global warming potential. The main objective of this research is to evaluate the influence of the exposure of CDW RA to CO2 produced in cement factories and its effect on mortars. Several mortars were developed with a volumetric ratio of 1:4 (cement: aggregate), with NA (reference mortar), CDW RA and CDW RA exposed to high levels of CO2 (CRA). The two types of waste aggregate were incorporated, replacing NA at 50% and 100% (in volume). The mortars with NA and non-carbonated RA and CRA from CDW were analysed, accounting for their performance in the fresh and hardened states in terms of workability, mechanical behaviour and water absorption by capillarity. It was concluded that mortars with CDW (both CRA and non-carbonated RA) generally present a good performance for non-structural purposes, although they suffer a moderate decrease in mechanical performance when NA is replaced with RA. Additionally, small improvements were found in the performance of the aggregates and mortars with CRA subjected to a CO2 curing for a short period (5 h), while a long carbonation period (5 d) led to a decrease in performance, contrary to the results obtained in the literature that indicate a significant increase in such characteristics. This difference could be because the literature focused on made-in-laboratory CDW aggregates, while, in this research, the wastes came from real demolition activities, and were thus older and more heterogeneous.

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Sulfate Resistance of Recycled Aggregate Concrete with GGBS and Fly Ash-Based Geopolymer

Materials ◽

10.3390/ma12081247 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1247 ◽

Cited By ~ 17

Author(s):

Jianhe Xie ◽

Jianbai Zhao ◽

Junjie Wang ◽

Chonghao Wang ◽

Peiyan Huang ◽

...

Keyword(s):

Fly Ash ◽

Construction Projects ◽

High Performance ◽

High Performance Concrete ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Aggregate Concrete ◽

Sulfate Resistance ◽

Coarse Aggregates

There is a constant drive for the development of ultra-high-performance concrete using modern green engineering technologies. These concretes have to exhibit enhanced durability and incorporate energy-saving and environment-friendly functions. The object of this work was to develop a green concrete with an improved sulfate resistance. In this new type of concrete, recycled aggregates from construction and demolition (C&D) waste were used as coarse aggregates, and granulated blast furnace slag (GGBS) and fly ash-based geopolymer were used to totally replace the cement in concrete. This study focused on the sulfate resistance of this geopolymer recycled aggregate concrete (GRAC). A series of measurements including compression, X-ray diffraction (XRD), and scanning electron microscopy (SEM) tests were conducted to investigate the physical properties and hydration mechanisms of the GRAC after different exposure cycles in a sulfate environment. The results indicate that the GRAC with a higher content of GGBS had a lower mass loss and a higher residual compressive strength after the sulfate exposure. The proposed GRACs, showing an excellent sulfate resistance, can be used in construction projects in sulfate environments and hence can reduce the need for cement as well as the disposal of C&D wastes.

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A Review on Alkali-Silica Reaction Evolution in Recycled Aggregate Concrete

Materials ◽

10.3390/ma13112625 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2625 ◽

Cited By ~ 3

Author(s):

Miguel Barreto Santos ◽

Jorge De Brito ◽

António Santos Silva

Keyword(s):

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Mitigation Measures ◽

Alkali Silica Reaction ◽

Aggregate Concrete ◽

Reactive Silica ◽

Natural Aggregates ◽

Exposure Conditions ◽

Lack Of Knowledge

Alkali-silica reaction (ASR) is one of the major degradation causes of concrete. This highly deleterious reaction has aroused the attention of researchers, in order to develop methodologies for its prevention and mitigation, but despite the efforts made, there is still no efficient cure to control its expansive consequences. The incorporation of recycled aggregates in concrete raises several ASR issues, mainly due to the difficult control of the source concrete reactivity level and the lack of knowledge on ASR’s evolution in new recycled aggregate concrete. This paper reviews several research works on ASR in concrete with recycled aggregates, and the main findings are presented in order to contribute to the knowledge and discussion of ASR in recycled aggregate concrete. It has been observed that age, exposure conditions, crushing and the heterogeneity source can influence the alkalis and reactive silica contents in the recycled aggregates. The use of low contents of highly reactive recycled aggregates as a replacement for natural aggregates can be done without an increase in expansion of concrete. ASR expansion tests and ASR mitigation measures need to be further researched to incorporate a higher content of recycled aggregates.

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