Relationship between the mechanical properties and carbonation of concretes with construction and demolition waste

Silva, Sérgio Roberto da; Cimadon, Felipe Nunes; Borges, Pietra Moraes; Schiavon, Jéssica Zamboni; Possan, Edna; Andrade, Jairo José de Oliveira

doi:10.1016/j.cscm.2021.e00860

Cited by 8 publications

(6 citation statements)

References 62 publications

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“…Calcite is a prominent mineral in recycled aggregate, but "quartz, alkali feldspars, muscovite, and dolomite" have also been recognized [31]. Similar results show the presence of crystalline phases such as quartz and calcite in RA samples compared with natural aggregate [32]. The presence of crystalline phases is consistent with the finding of quartz and calcite in the recycled aggregate's X-ray Diffraction (XRD) pattern, as shown in Figure 3.…”

Section: Composition Of Recycled Aggregatesupporting

confidence: 81%

A Comprehensive Review on Recycling of Construction Demolition Waste in Concrete

et al. 2023

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There have been efforts to use building demolition waste as an alternative aggregate in concrete to decrease the use of natural resources for construction. The World Green Building Council estimates that the construction industry is responsible for more than 50% of all material extracted globally and that construction and demolition waste makes up 35% of global landfills. As a result, incorporating recycled aggregate (RA) in concrete production is a prudent course of action to reduce the environmental impact. This study reviews prior research on using recycled aggregate instead of conventional ingredients in concrete. The composition and morphology of different types of RA, the behavior of RA in fresh and hardened states, keyword co-occurrence and evolution analysis, and the various additives used to enhance the inferior properties of RA are discussed. The RA showed different physical properties when compared with natural aggregate. However, the addition of pozzolanic materials and various pretreatment techniques is desirable for improving the inferior properties of RA. While building waste has been utilized as a substitute for fine and coarse aggregate, prior research has demonstrated that a modified mixing approach, an adequate mixing proportion, and the optimum replacement of cementitious materials are necessary. Based on the review, the recommendation is to use RA at a replacement level of up to 30% and the addition of precoated and pozzolanic materials as a treatment to provide concrete with adequate workability, strength, and durability for structural applications.

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Section: Composition Of Recycled Aggregatesupporting

confidence: 81%

A Comprehensive Review on Recycling of Construction Demolition Waste in Concrete

et al. 2023

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“…Pozzolanic materials are environmentally friendly supplemental cementitious materials (SCMs) widely used in concrete as a partial cement substitute. SCMs have recently become popular due to the growing need for durable and sustainable concrete with strong resistance to harmful long-term chemical reactions [1,2]. Furthermore, eco-friendly cement alternatives help reduce carbon dioxide emissions in the atmosphere [3].…”

Section: Introductionmentioning

confidence: 99%

Fly Ash and Natural Pozzolana Impacts on Sustainable Concrete Permeability and Mechanical Properties

Mohsen,

Aburumman,

Al Diseet

et al. 2023

Buildings

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This paper studied the effect of fly ash (FA) and natural pozzolana (NP) as partial cement substitutes on sustainable concrete permeability and mechanical and microstructural properties. Batches with 10, 20, 30, 40, and 50% FA and NP replacements for cement were prepared and tested for compressive strength after 7, 28, and 56 curing days and for flexural strength after 28 curing days. Permeability testing was conducted on all samples. A qualitative microstructural analysis was performed using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The mechanical properties results showed slight strength improvements when replacing the cement with low percentages of the pozzolanic materials. The compressive strengths of the batches with 10% FA and NP replacements of cement showed compressive strength increases of 11.63 and 8.75%, respectively, compared to that of plain concrete. On the other hand, the flexural strength for the batches with FA replacement of cement achieved at least a 15.6% increase compared to that of the control. Moreover, FA and NP replacement of cement had a positive impact on batch permeability, with decreased permeability values reaching 78.3 and 56.5%, respectively, compared to that of the control. Furthermore, the microstructural analysis indicated that adding FA and NP would enhance cement hydration by the formation of dense hydration products such as calcium–silicate–hydrate (C-S-H) crystals, which increased hardened concrete strength. Finally, the cost analysis showed that the batch with a 10% FA replacement of cement is the ideal one in this study.

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“…Moreover, since the current standards on structural concrete include the reuse of old concrete from CDW, this action is highly indicated for economic and environmental savings, as well as reducing of CDW volume. In fact, the sustainable management of resources is directly related to new perspectives of construction, with the application of the life cycle assessment (LCA) methodology [29][30][31][32], in which the reduction of the environmental impact of buildings is enhanced by renewable or recycled materials with low industrial processing [33][34][35][36], with these policies for cost reintegration being considered a key question in new building development.…”

Section: Introductionmentioning

confidence: 99%

Technical-Economic Opportunities of Mixture Optimization and Recycled Aptitude at a Pre-Casting Concrete Plant

Montero

Cervera-Gascó

2023

Applied Sciences

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Cost optimization is a key factor in the competitiveness of construction companies. Hence, in the case of a concrete manufacturing plant, the technical-economic optimization of the process involved in producing concrete is a determining factor in its activity being more competitive than that of other companies. Thus, the main objective of this experimentation is the optimization of the different concrete dosages used in a pre-casting plant. The cement volume, the water/cement (W/C) ratio, the influence of an accelerator additive and replacing coarse aggregate with recycled aggregate were analysed. As an application of the economic results, three different hypotheses were analysed for different mix combinations in a real concrete structure model. The results show that it is essential to monitor the actual initial moisture state of aggregates and the perfect definition of the effective water/cement ratio of the dosage (Wef/C) in manufacturing in order to obtain more homogeneous production. It is proposed to simplify the number of different mix proportions and reduce cement by 10–20% without decreasing resistance and functional capabilities. Regarding additive optimization, the results show that using low rates of accelerator additive significantly improves compressive strength. Replacing natural aggregates with recycled aggregates obtained from the concrete waste of non-conforming elements is suited to manufacturing recycled concrete using replacement rates of 50% and 100%. The cost analysis for a real industrial building applying the different dosing options studied shows that a cost reduction of up to 17.8% can be achieved.

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Relationship between the mechanical properties and carbonation of concretes with construction and demolition waste

Cited by 8 publications

References 62 publications

A Comprehensive Review on Recycling of Construction Demolition Waste in Concrete

A Comprehensive Review on Recycling of Construction Demolition Waste in Concrete

Fly Ash and Natural Pozzolana Impacts on Sustainable Concrete Permeability and Mechanical Properties

Technical-Economic Opportunities of Mixture Optimization and Recycled Aptitude at a Pre-Casting Concrete Plant

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