scholarly journals Construction and Demolition Waste (CDW) Recycling—As Both Binder and Aggregates—In Alkali-Activated Materials: A Novel Re-Use Concept

2020 ◽  
Vol 12 (14) ◽  
pp. 5775 ◽  
Author(s):  
Rafael A. Robayo-Salazar ◽  
William Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Circular Economy ◽  
Room Temperature ◽  
Heat Of Hydration ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
High Class ◽  
Construction And Demolition Wastes ◽  
Alkali Activated

This article demonstrates the possibility of producing alkali-activated materials (AAM) from a mixture of mechanically processed concrete, ceramic, masonry, and mortar wastes, as a sustainable alternative for recycling construction and demolition wastes (CDWs) under real conditions. The addition of 10% Portland cement allowed the materials to cure at room temperature (25 °C). CDW binder achieved a compressive strength of up to 43.9 MPa and it was classified as a general use and low heat of hydration cement according to ASTM C1157. The concrete produced with this cement and the crushed aggregates also from CDW reported a compressive strength of 33.9 MPa at 28 days of curing and it was possible to produce a high-class structural block with 26.1 MPa according to ASTM C90. These results are considered one option in making full use of CDWs as binder and aggregates, using alkaline activation technology thereby meeting the zero-waste objective within the concept of the circular economy.

scholarly journals Alkali-Activated Hybrid Cements Based on Fly Ash and Construction and Demolition Wastes Using Sodium Sulfate and Sodium Carbonate

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7572
Author(s):  
William Valencia-Saavedra ◽  
Rafael Robayo-Salazar ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Sodium Carbonate ◽  
Sodium Sulfate ◽  
Room Temperature ◽  
Ordinary Portland Cement ◽  
Mechanical Performance ◽  
Construction And Demolition Wastes ◽  
Alkali Activated

This article demonstrates the possibility of producing alkali-activated hybrid cements based on fly ash (FA), and construction and demolition wastes (concrete waste, COW; ceramic waste, CEW; and masonry waste, MAW) using sodium sulfate (Na2SO4) (2–6%) and sodium carbonate (Na2CO3) (5–10%) as activators. From a mixture of COW, CEW, and MAW in equal proportions (33.33%), a new precursor called CDW was generated. The precursors were mixed with ordinary Portland cement (OPC) (10–30%). Curing of the materials was performed at room temperature (25 °C). The hybrid cements activated with Na2SO4 reached compressive strengths of up to 31 MPa at 28 days of curing, and the hybrid cements activated with Na2CO3 yielded compressive strengths of up to 22 MPa. Based on their mechanical performance, the optimal mixtures were selected: FA/30OPC-4%Na2SO4, CDW/30OPC-4%Na2SO4, FA/30OPC-10%Na2CO3, and CDW/30OPC-10%Na2CO3. At prolonged ages (180 days), these mixtures reached compressive strength values similar to those reported for pastes based on 100% OPC. A notable advantage is the reduction of the heat of the reaction, which can be reduced by up to 10 times relative to that reported for the hydration of Portland cement. These results show the feasibility of manufacturing alkaline-activated hybrid cements using alternative activators with a lower environmental impact.

scholarly journals Research On Recycling Of Hardened Mortar From Construction And Demolition Waste

2015 ◽  
Vol 5 (2) ◽  
pp. 81-86
Author(s):  
Irina Smical ◽  
F. Filip-Văcărescu ◽  
G. Danku ◽  
V. Paşca
Keyword(s):  
Sustainable Development ◽  
Compressive Strength ◽  
Circular Economy ◽  
Standard Sample ◽  
Testing Machine ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
The Sustainable Development ◽  
Concrete Production ◽  
Compression Resistance

Abstract The recycling issues related to the construction and demolition (C&D) wastes in the sustainable development and the circular economy context represent a continuous challenge for researchers. This paper reveals the possibility to recycle the hardened mortar recovered from C&D wastes. Thus, the recovered hardened mortar with grains size less than 16 mm was used in the concrete structure. The compression resistance of the final concrete was determined using a Heckert 3000 KN testing machine and the results showed a better compressive strength for the samples with C&D waste content than the standard sample of about 1.19 times. This is a good premise for improving the researches related to C&D waste usage in concrete production.

scholarly journals Acid Resistance of Lightweight Brick Powder Based Alkali Activated Material from Construction and Demolition Wastes

2018 ◽  
Author(s):  
Kai Tai Wan ◽  
Amende Sivanathan ◽  
Gediminas Kastiukas ◽  
Xiangming Zhou
Keyword(s):  
Acid Resistance ◽  
Strength Loss ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Construction And Demolition Wastes ◽  
Brick Powder ◽  
Structural Applications ◽  
The Matrix ◽  
Similar Density ◽  
Alkali Activated

The annual construction and demolition waste (CDW) generated from EU construction sector was 850 million tons, which represented 31% of the total waste generation and about 28% of CDW was ceramics (bricks and tiles). In this study, the feasibility of using CDW brick powder as the precursor of alkali activated mortar (AAM) and extruded polystyrene (XPS) as the lightweight aggregates to form lightweight brick powder AAM (LW-BP-AAM) for non-structural applications was investigated. The thermal conductivity of LP-BPAAM was 0.112 W/m·K with density of about 1,135 kg/m3 which was lower than the counterparts with similar density in literature. The acid resistance of LW-BP-AAM is comparable to conventional fly ash based AAM and superior than ordinary Portland cement. From the scanning electron microscopy with energy dispersive X-ray spectroscopy, there was no severe damage on the surface of LW-BP-AAM but aluminate was removed from the matrix which was further verified in Fourier transform infrared spectroscopy. The mass and strength loss of LP-BP-AAM was 1.5% and 33%, respectively. Although the compressive strength of the LP-BP-AAM was low (about 1.8 MPa), it can be improved by optimising the particle size of the XPS aggregates.

scholarly journals ANÁLISE COMPARATIVA ENTRE COMPÓSITOS MINERAIS PRODUZIDOS COM PARTÍCULAS DE MADEIRA PASSANTE NA PENEIRA 1,2 mm

2020 ◽  
Vol 15 (2) ◽  
pp. 233-244
Author(s):  
Thaísa Mariana Santiago Rocha ◽  
Leonardo Fagundes Rosemback Miranda
Keyword(s):  
Compressive Strength ◽  
Specific Gravity ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
Construction And Demolition Waste ◽  
Wood Composites ◽  
Demolition Waste ◽  
Wood Residues ◽  
Wood Particles ◽  
Strength And Durability

RESUMO: Os compósitos de madeira surgiram como alternativa para o aproveitamento dos resíduos de construção e demolição (RCD) de madeira. O cimento Portland tem sido utilizado como aglomerante conferindo resistência e durabilidade, entretanto a combinação destes materiais pode resultar na inibição da pega. Em contrapartida, poucos estudos têm sido realizados com compósitos de madeira utilizando o gesso como aglomerante. O objetivo deste trabalho consiste em avaliar a influência de dois diferentes aglomerantes (cimento Portland e gesso) nas propriedades físicas e mecânicas de compósitos produzidos com partículas de madeira (de compensado, eucalipto e pínus), provenientes de resíduos de construção e demolição (RCD), passante na peneira 1,2 mm. Os resíduos de madeira de construção foram moídos, tratados, peneirados e caracterizados através da massa unitária e do teor de umidade. Foi utilizado o cimento CPV-ARI, o gesso de pega lenta, o aditivo acelerador de pega. Foram realizados os ensaios de densidade endurecida, resistência à tração na flexão e resistência à compressão, aos 28 dias. Os resultados indicaram que quanto maior a quantidade de partículas de madeira na composição, menor é a densidade e a resistência à compressão do compósito. Todos os compósitos produzidos com cimento-madeira apresentaram densidade inferior ao estipulado pela NBR 15498. As densidades dos compósitos de gesso-madeira, no teor de 15% de partículas, aproximaram-se dos valores indicados pela NBR 14715. ABSTRACT: Wood composites appear as an alternative for the reuse of construction and demolition waste (CDW) of wood. Portland cement has been used as a binder conferring strength and durability, however the combination of these materials may result in handle inhibition. In contrast, few studies have been carried out with wood composites using gypsum as a binder. In this paper the influence of two binders (Portland cement and gypsum) was evaluated in relation to the physical and mechanical properties of composites produced from wood particles (plywood, eucalyptus and pine) from construction and demolition waste (CDW) passing on the size  1.2 mm. The wood residues were ground, treated, sieved and characterized by unit mass and moisture content. The CPV-ARI cement was used, the slow gypsum plaster, the handle accelerator additive. The tests of hardened specific gravity, flexural and the compressive strength in the hardened stage at 28 days. The results indicated that the higher the amount of wood particles in the composition, the lower hardened specific gravity and the compressive strength of the composite. All composites produced with cement-wood presented a hardened specific gravity lower than that stipulated by NBR 15498. The hardened specific gravity of the gypsum-wood composites, in the content of 15% of particles, approached the values indicated by NBR 14715.

scholarly journals Effects of the incorporation of residue of masonry on the properties of cementitious mortars

2020 ◽  
Vol 19 (3) ◽  
pp. 407-421
Author(s):  
Yimmy Fernando Silva ◽  
◽  
David A. Lange ◽  
Silvio Delvasto ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Activity Index ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Heat Of Hydration ◽  
Cementitious Material ◽  
Pozzolanic Activity ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Supplementary Cementitious Material

This paper presents results of an experimental study of a residue of masonry (RM), sampled from a construction and demolition waste (CDW), added as a supplementary cementitious material (SCM) to partially replace up to 50% of Portland cement in the preparation of mortars. The pozzolanic activity (fixed lime and strength activity index), setting time, heat of hydration, the (autogenous and drying) shrinkage and compressive strength tests were carried out. The results show how the RM has a positive activity because the increase of RM replacement level in the mortars generates a lower heat of hydration and autogenous and drying shrinkage. The fixed lime at 28 and 180 days, indicating that the RM exhibits in some degree pozzolanic activity and the Strength Activity Index (SAI) was 77.13% and 84.36% of the compressive strength of 100% OPC mortar at the 7 and 28 days respectively, which conformed to ASTM C311. These results indicate that RM should be considered appropriated for using as a supplementary cementitious material.

scholarly journals Eco-House Prototype Constructed with Alkali-Activated Blocks: Material Production, Characterization, Design, Construction, and Environmental Impact

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1275
Author(s):  
Rafael A. Robayo-Salazar ◽  
William Valencia-Saavedra ◽  
Sandra Ramírez-Benavides ◽  
Ruby Mejía de Gutiérrez ◽  
Armando Orobio
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Construction And Demolition Waste ◽  
Sustainable Construction ◽  
Alkali Activation ◽  
Demolition Waste ◽  
Earthquake Resistant ◽  
Concrete Blocks ◽  
Alkali Activated ◽  
Design And Construction

The interest of the construction industry in alkali-activated materials has increased to the extent that these materials are recognized as alternatives to ordinary Portland cement-based materials in the quest for sustainable construction. This article presents the design and construction of a prototype of an eco-friendly house built from concrete blocks produced using alkali activation technology or geopolymerization. The prototype meets the requirements of the current Colombian Regulations for Earthquake Resistant Buildings (NSR-10) and includes standards related to the performance of the materials, design, and construction method for earthquake-resistant confined masonry of one- or two-story buildings. The alkali-activated blocks were obtained from different precursors (aluminosilicates), including a natural volcanic pozzolan, ground granulated blast furnace slag, fly ash, construction and demolition waste (concrete, ceramic, brick, and mortar), and red clay brick waste. The physical-mechanical characterization of the alkali-activated blocks allowed their classification according to the structural specifications of the Colombian Technical Standard NTC 4026 (equivalent to ASTM C90). The global warming potential (GWP) or “carbon footprint” attributed to the raw materials of alkali-activated blocks was lower (25.4–54.7%) than that of the reference blocks (ordinary Portland cement concrete blocks). These results demonstrate the potential of alkali-activated materials for application in the construction of eco-friendly houses.

The Traceability of Construction and Demolition Waste in Flanders via Blockchain Technology: A Match Made in Heaven?

2021 ◽  
Vol 18 (4) ◽  
pp. 347-369
Author(s):  
Jonas Voorter ◽  
Christof Koolen
Keyword(s):  
Circular Economy ◽  
Construction And Demolition Waste ◽  
Waste Processing ◽  
Construction Sector ◽  
Sustainable Society ◽  
Demolition Waste ◽  
Blockchain Technology ◽  
Legal Case ◽  
Made In

Abstract The construction sector plays a crucial role in the transition to a circular economy and a more sustainable society. With this objective in mind, Flanders – the Dutch speaking part of Belgium – makes use of a traceability procedure for construction and demolition waste in order to guarantee that value can be derived from downstream waste processing activities. This article takes this traceability procedure as a legal case study and examines if the use of blockchain technology could lead to even stronger supply chains, better data management, and, more generally, a smoother transition to circular practices in the construction sector.

scholarly journals Valorization of Brick and Glass CDWs for the Development of Geopolymers Containing More Than 80% of Wastes

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 672
Author(s):  
Dimitris Kioupis ◽  
Aggeliki Skaropoulou ◽  
Sotirios Tsivilis ◽  
Glikeria Kakali
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Circular Economy ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
X Ray ◽  
Optimum Synthesis ◽  
Synthesis Parameters ◽  
Construction And Demolition Wastes ◽  
Scanning Electron

One of the areas of priority in a circular economy, regarding waste management, regards the valorization of construction and demolition wastes (CDW). This study suggests the synthesis of geopolymeric binders based almost entirely on construction and demolition wastes. Ceramic waste was used as the aluminosilicate precursor of the geopolymer synthesis, while glass waste was applied in the preparation of the activation solution. A fractional experimental design defined the optimum synthesis parameters, based on compressive strength values. The final products were characterized by means of X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The glass waste was appropriately processed in order to prepare the activation solution for the geopolymerization of brick waste. In this work, CDW-based geopolymers were produced with a compressive strength in the range 10–44 MPa. The developed products contained 80–90 wt.% CDWs, depending on the method of activator preparation.

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

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2970 ◽  
Author(s):  
Clarence P. Ginga ◽  
Jason Maximino C. Ongpeng ◽  
Ma. Klarissa M. Daly
Keyword(s):  
Literature Review ◽  
Circular Economy ◽  
Business Models ◽  
Latent Dirichlet Allocation ◽  
Traditional Approach ◽  
Construction And Demolition Waste ◽  
The European Union ◽  
Demolition Waste ◽  
Material Recovery ◽  
New Construction

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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