Development of a fly ash-based geopolymeric concrete with construction and demolition wastes as aggregates in acoustic barriers

Arenas, Celia; Luna-Galiano, Y.; Leiva, Carlos; Vilches, Luís F.; Arroyo, F.; Villegas, R.; Fernández‐Pereira, Constantino

doi:10.1016/j.conbuildmat.2016.12.119

Cited by 89 publications

(48 citation statements)

References 41 publications

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“…Furthermore, decreasing the molarity of sodium hydroxide (16 M to 8 M) in alkali-activated concretes containing RA decreased the flexural strength [28]. In the same way, in fly ash-based geopolymers, Arenas et al [76] used two different coarse aggregates, crushed granite, and RA activated by two different molar ratios (Na 2 O/SiO 2 ), 0.29 and 0.98. The compressive strength of Na 2 O/SiO 2 :0.29 was lower than that of Na 2 O/SiO 2 :0.98 due to a lower rate of aluminosilicate dissolution.…”

Section: Ra In Alkali-activated Concretesmentioning

confidence: 99%

Construction and Demolition Waste as Recycled Aggregates in Alkali-Activated Concretes

et al. 2019

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The growth of global construction has contributed to an inevitable increase in the amount of construction and demolition (C&D) waste, and the recycling of C&D waste as aggregates in concrete is receiving increased interest, resulting in less demand for normal aggregates and bringing a potential solution for the landfilling of wastes. Recently, several studies have focused on the use of C&D waste in alkali-activated concrete to move one step closer to sustainable concretes. This paper focuses on the main mechanisms of using C&D waste in the resulting physical, mechanical, and durability properties of alkali-activated concrete in fresh and hardened state properties. The main difficulties observed with recycled aggregates (RA) in concrete, such as high levels of water demand, porous structure, and low mechanical strength, occur in RA alkali-activated concretes. These are associated with the highly porous nature and defects of RA. However, the high calcium concentration of RA affects the binder gel products, accelerates the hardening rate of the concrete, and reduces the flowability of alkali-activated concretes. For this reason, several techniques have been investigated for modifying the water content and workability of the fresh matrix and for treating RA and RA/alkali-activated binder interactions to produce more sustainable alkali-activated concretes.

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Section: Ra In Alkali-activated Concretesmentioning

confidence: 99%

Construction and Demolition Waste as Recycled Aggregates in Alkali-Activated Concretes

et al. 2019

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“…The construction industry and demolition process after the expiration of the life-cycle of a building or structure is one that produces a considerable amount of waste. In the European Union, approximately 930 million tons in 2016 [ 1 ] and 2.36 billion tons in China in 2018 [ 2 ]. The mentioned industry is responsible for the production of considerable amounts of waste and the increasing volume has become unbearable for the environment, economic, and social viewpoints [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

Circular Economy on Construction and Demolition Waste: A Literature Review on Material Recovery and Production

2020

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Construction and demolition waste (CDW) accounts for at least 30% of the total solid waste produced around the world. At around 924 million tons in the European Union in 2016 and 2.36 billion tons in China in 2018, the amount is expected to increase over the next few years. Dumping these wastes in sanitary landfills has always been the traditional approach to waste management but this will not be feasible in the years to come. To significantly reduce or eliminate the amount of CDW being dumped, circular economy is a possible solution to the increasing amounts of CDW. Circular economy is an economic system based on business models which replaces the end-of-life concept with reducing, reusing, recycling, and recovering materials. This paper discusses circular economy (CE) frameworks—specifically material recovery and production highlighting the reuse and recycling of CDW and reprocessing into new construction applications. Likewise, a literature review into recent studies of reuse and recycling of CDW and its feasibility is also discussed to possibly prove the effectivity of CE in reducing CDW. Findings such as effectivity of recycling CDW into new construction applications and its limitations in effective usage are discussed and research gaps such as reuse of construction materials are also undertaken. CE and recycling were also found to be emerging topics. Observed trends in published articles as well as the use of latent Dirichlet allocation in creating topic models have shown a rising awareness and increasing research in CE which focuses on recycling and reusing CDW.

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“…On the one hand, an increasing amount of different types of waste is being recycled as fine and coarse aggregates in concrete manufacturing as a substitution for natural aggregates. Some examples are ashes, bottom ashes, and slags [17]; construction and demolition wastes [18]; and farming wastes, such as corn, wheat, bamboo, coconut shells, and olive stone [19,20]. On the other hand, the aquaculture industry produces between 6,000,000 and 8,000,000 tons of waste worldwide annually and only 25% is recycled [21], and the rest is usually dumped in coastal waters or landfills [22].…”

Section: Introductionmentioning

confidence: 99%

Is Recycling Always the Best Option? Environmental Assessment of Recycling of Seashell as Aggregates in Noise Barriers

et al. 2020

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Waste recycling is an essential part of waste management. The concrete industry allows the use of large quantities of waste as a substitute for a conventional raw material without sacrificing the technical properties of the product. From a circular economy point of view, this is an excellent opportunity for waste recycling. Nevertheless, in some cases, the recycling process can be undesirable because it does not involve a net saving in resource consumption or other environmental impacts when compared to the conventional production process. In this study, the environmental performance of conventional absorption porous barriers, composed of 86 wt % of natural aggregates and 14 wt % cement, was compared with barriers composed of 80 wt % seashell waste and 20 wt % cement through an attributional cradle-to-grave life cycle assessment. The results show that, for the 11 environmental impact categories considered, the substitution of the natural aggregates with seashell waste involves higher environmental impacts, between 32% and 267%. These results are justified by the high contribution to these impacts of the seashell waste pre-treatment and the higher cement consumption. Therefore, the recycling of seashells in noise barrier manufacturing is not justified from an environmental standpoint with the current conditions. In this sense, it could be concluded that life cycle assessments should be carried out simultaneously with the technical development of the recycling process to ensure a sustainable solution.

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Development of a fly ash-based geopolymeric concrete with construction and demolition wastes as aggregates in acoustic barriers

Cited by 89 publications

References 41 publications

Construction and Demolition Waste as Recycled Aggregates in Alkali-Activated Concretes

Construction and Demolition Waste as Recycled Aggregates in Alkali-Activated Concretes

Circular Economy on Construction and Demolition Waste: A Literature Review on Material Recovery and Production

Is Recycling Always the Best Option? Environmental Assessment of Recycling of Seashell as Aggregates in Noise Barriers

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