Physical, chemical and mineralogical properties of fine recycled aggregates made from concrete waste

Evangelista, Luís; Guedes, M.; Brito, Jorge de; Ferro, A.C.; Pereira, M.F.C.

doi:10.1016/j.conbuildmat.2015.03.112

Cited by 218 publications

(98 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Compared to the values of bond-slip curve of steel bar with 5d bond length in manufactured sand concrete [46], the values of τ s /f t,0 , τ cr /f t,0 and τ u /f t,0 presented in Table 8 are larger while those of s s , s cr and s u are lower. This presents a better bond property of deformed steel bar to aRAC, due to the enhancement of the secondary hydration of cement grains composited in fine RCA on the interface between deformed steel bar and aRAC [20,21]. Similar test results have been reported for the bond strength between deformed steel bar and RAC [26,31].…”

Section: Modeling Of Bond-slip Relationshipsupporting

confidence: 72%

“…Meanwhile, compared with natural sand, fine RCA has very different characteristics such as angular and irregular particles, high mortar contents, non-uniform morphology for containing a mixture of C-S-H and CH formations, and low density and high water absorption as result of the heterogeneous nature of natural aggregate and cement paste. These characteristics of fine RCA lead to the much complexity and variations in mix proportion, workability, mechanical properties and durability of RAC [3,4,20,21]. Based on the reviews of current researches, the production of full-recycled-aggregate concrete (aRAC) made of 100% coarse and fine recycled aggregates is a new approach to improve the efficiency of reusing all recycled products of waste concrete [22,23].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bond Behaviors Between Full-Recycled-Aggregate Concrete and Deformed Steel-Bar

Li¹,

Zhao²,

Ren³

et al. 2017

TOCIEJ

View full text Add to dashboard Cite

Introduction:Full-recycled-aggregate concrete (aRAC) is a new concrete reusing 100% fine and coarse recycled aggregates produced from waste concrete of demolished concrete structures. As there is a lack of studies on the bond behavior between steel bar and aRAC, findings of this study are of significance for the structural application of aRAC. Method:This paper presents the pull-out test results of 24 groups aRAC specimens with deformed steel bar, and discusses the effects of aRAC strength, bond length and lateral constructional stirrups on the bond behavior between deformed steel bar and aRAC. Results and Conclusion:The bond stress and slip at key points of bond-slip curve are analyzed in relation to the tensile strength of aRAC and the bond length of steel bar. The bond-slip relationship between deformed steel bar and aRAC is proposed based on the test and analysis of this study.

show abstract

Section: Modeling Of Bond-slip Relationshipsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Bond Behaviors Between Full-Recycled-Aggregate Concrete and Deformed Steel-Bar

Li¹,

Zhao²,

Ren³

et al. 2017

TOCIEJ

View full text Add to dashboard Cite

show abstract

“…During this grinding process, the Ca(OH) 2 is released from the cement paste and is exposed directly to the CO 2 in the air, therefore part of the CaCO 3 detected in the diffractogram belongs to the carbonate generated after the grinding necessary for the powder diffraction technique. Mymrin et al [21], mentioned that the peaks of portlandite Ca(OH) 2 became lower than the detection limit of the XRD method (approximately 5%), in the same way, Evangelista et al [14] indicated that concrete waste presents low Ca(OH) 2 amounts (below 2.6 wt %).…”

Section: Minerals Of the Adhered Cement Pastementioning

confidence: 96%

“…Curiously, plant-recycled sand presented a higher content of fine particles (<75 µ) than laboratory-recycled sand, which contradicts the argument that when the quality of the demolished concrete is high, the recycled aggregates will be larger and more resistant due to the resistance of adhered material. However, the plant-processed sands underwent a more complex grinding and sieving process entailing higher fragmentation as a result of agitation and transportation [14], as opposed to laboratory sands, which were crushed in a single cycle and sieved by hand.…”

Section: Mineralogical Compositionmentioning

confidence: 99%

Chemical and Mineralogical Characterization of Recycled Aggregates from Construction and Demolition Waste from Mexico City

et al. 2018

View full text Add to dashboard Cite

Abstract:In this study, four samples of recycled aggregates from the construction and demolition waste of Mexico City were characterized in order to find innovative uses for these types of materials. Gravel and sand from a recycling plant were analyzed, as well as aggregates produced in the laboratory from demolished concrete collected from landfills. The characterization was carried out by means of XRD (X-ray Diffraction), chemical microanalysis (EDS), X-ray fluorescence (XRF), pH measurement, and sieve analysis. The minerals present in the analyzed materials were feldspars, cristobalite and pyroxene, which corresponded to the natural aggregates, as well as variable amounts of calcite, a product of the carbonation of the cement paste adhered to these aggregates, and in a smaller proportion, calcium hemicarboaluminate, rosenhanite, and tobermorite. The quality (amount of cement) of the original concrete has a great influence on the granulometry and the chemical-mineralogical composition of the aggregates, since there will be different quantities and qualities of the cement paste adhered to the aggregates depending on their size. Finally, the pH values measured in all samples fluctuated between 10.15 and 12.08, suggesting that these materials can be used in soil stabilization or in agricultural applications.

show abstract

“…Los agregados fueron reemplazados en su totalidad por residuos cerámicos para evitar el uso de agregados naturales y demostrar la eficiencia del uso de materiales alternos [27]. Las placas fueron fabricadas con una perforación central, que se utilizó posteriormente para brindarle estabilidad vertical al montaje en el fondo marino a través de un accesorio de madera (Fig.…”

Section: Fabricación De Las Muestrasunclassified

Biological and physicochemical evaluation of mortar as substrate for manufacturing artificial reef

et al. 2016

View full text Add to dashboard Cite

Due to several deterioration of coral reefs around the world, has increased the need to rehabilitate marine environments. Artificial reefs have been proposed as a tool for conservation of these ecosystems. As part of an initiative to develop modules forming artificial reefs made of ecological concrete for the conservation of the biodiversity in the Colombian Caribbean; this work constitutes a starting point. During eleven months two trapezoidal plates were submerged near to Isla Palma, Colombian Caribbean; plates were fabricated in concrete with portland cement and the aggregates were replaced by ceramic waste. After biological and physicochemical evaluations of the material exposed to marine environment was concluded that this is a favorable substrate for the coral reefs, and the plates were colonized by more than 30% of its surface by marine organisms, their structure found internally stable, and there were no adverse effects on marine biota near the test site.Keywords: Ecological mortars; artificial reefs; waste resource; use of waste; conservation.Evaluación biológica y fisicoquímica de un mortero como sustrato para la fabricación de arrecifes artificiales Resumen Debido al deterioro de los arrecifes de coral en todo el mundo ha aumentado la necesidad de rehabilitar los entornos marinos. Los arrecifes artificiales se han propuesto como una herramienta para la conservación de estos ecosistemas. Durante once meses se sumergieron dos placas en forma trapezoidal, en Bajo Grande (Isla Palma), Caribe Colombiano. Esto se realizó como parte de una iniciativa para desarrollar módulos formadores de arrecifes artificiales. Se fabricó un mortero ecológico donde se reemplaza el uso de agregados naturales por residuos cerámicos. Las placas expuestas al medio marino fueron colonizadas por organismos en un 30% de su superficie aproximadamente, la estructura interna de las muestras se mantuvo estable y no se apreciaron efectos adversos sobre la biota marina cercana al lugar de prueba. Después de hacer evaluaciones biológicas y fisicoquímicas del material expuesto se concluyó que éste constituye un sustrato favorable para el desarrollo de los arrecifes artificiales.

show abstract

Physical, chemical and mineralogical properties of fine recycled aggregates made from concrete waste

Cited by 218 publications

References 45 publications

Bond Behaviors Between Full-Recycled-Aggregate Concrete and Deformed Steel-Bar

Bond Behaviors Between Full-Recycled-Aggregate Concrete and Deformed Steel-Bar

Chemical and Mineralogical Characterization of Recycled Aggregates from Construction and Demolition Waste from Mexico City

Biological and physicochemical evaluation of mortar as substrate for manufacturing artificial reef

Contact Info

Product

Resources

About