Use of aggregates from recycled construction and demolition waste in concrete

Recycling of construction and demolition waste (CDW) has become a widespread concern in Spain for the last years, as a way to preserve natural resources and achieve a better control of waste disposal sites. Specific applications which make use of mixed recycled aggregates are of great importance, as this types of aggregates constitute the majority of the total production. Structural and non-structural concrete is one of the possible applications, being this the main goal of our study.This paper presents a study on the physical and chemical characteristics of mixed recycled aggregates which have been obtained from different CDW treatment plants of Spain. Correlations between the different properties were investigated in order to find criterions of acceptance for recycled aggregates to be used in concrete.The comparison between the properties offers the possibility of pre-selecting a great quantity of mixed recycled aggregates, these being suitable for either structural and non-structural concrete. The determination of water absorption and the gypsum content are good indicators in order to evalúate the quality of the mixed recycled aggregates for its application in the production of concrete.

show abstract

“…These values are quite similar to those obtained in different studies consulted in bibliography [18][19][20][21].…”

Section: Laboratory Testingsupporting

confidence: 90%

Limiting properties in the characterisation of mixed recycled aggregates for use in the manufacture of concrete

Agrela

Juan

Ayuso

et al. 2011

Construction and Building Materials

199

View full text Add to dashboard Cite

show abstract

“…As noted earlier, RCA's absorption capacity has been shown to be significantly higher than virgin aggregate, depending on the RCA's composition, ranging from 3-12% (Katz, 2003;Rao, Jha et al, 2007). The standard test method for determining the absorption capacity of aggregates, ASTM C128, is not currently approved for use with RCA (ASTM C128, 2007) because it states a soak time of 24 ± 4 hours is required to reach full saturation.…”

Section: Absorption Capacitymentioning

confidence: 99%

Durability Assessment of Recycled Concrete Aggregates for Use in New Concrete Phase II

Ideker¹

2014

View full text Add to dashboard Cite

Type of Report and Period Covered14. Sponsoring Agency Code 15. Supplementary Notes 16. Abstract: This Phase II investigation into the durability of new concrete incorporating recycled concrete aggregates (RCA) focused on several goals: 1) Provide corroboration of results obtained in Phase I for a multi-laboratory study related to assessing alkali-silica reactivity (ASR) of RCA in accelerated laboratory tests; 2) Investigate the efficacy of mitigation methods to control ASR in concrete containing potentially reactive RCA; 3) Establish long-term data through placement of concrete blocks containing RCA in an outdoor exposure site in Laramie, WY; and 4) Survey state DOTs and other transportation agencies about their perceptions and usage of RCA ASR in concrete within their agency and how that may be improved through the use of a database tracking tool. From Phase II the following main conclusions were drawn: 1) The coefficient of variation limits in ASTM C 1260-07 do not apply to concrete mortar bars incorporating RCA. It is recommended that further testing, using different RCA and more laboratories (at least six), should be completed before a new standard for RCA and/or incorporation of RCA into the current ASTM C 1260 test may be allowed. 2) Generally, as the replacement level of RCA was reduced, the amount of SCM needed to control deleterious ASR also decreased for the RCA sources investigated in this study. 3) Ternary blends containing metakaolin resulted in the most significant decrease in expansions compared to the mixtures with no SCMs.The results of the transportation agency survey showed the following: 1) A vast majority of agencies believed that sustainability was important to their agency and that it was addressed in a clear and meaningful way. 2) A majority, 54%, of agencies believed they had specific guidance for the use of RCA in new concrete; however, only 15% believed that there was strong information from the federal level about the use of RCA in new construction. 3) Of all respondents, 77% indicated their agency was concerned about alkali-silica reaction in concrete in general for their agency. 4) The biggest barriers to using RCA were noted as concerns about quality, a lack of standards and specifications, and unclear guidance on the testing of RCA. 5) The biggest concerns specific to a source of RCA when considering it for use in new construction were increased shrinkage concerns, ASR and residual chlorides. 6) The most sought-after information about a potential RCA source when considering it for use were the existing condition of the RCA when it was taken out of service, the reason it was taken out of service, whether repairs were performed to the structural element taken out of service, and the age of the RCA. 17.

show abstract

“…Em termos globais, isso responde pelo uso de 40% das matérias-primas retiradas do meio ambiente, o que totaliza 60% de toda a madeira extraída, 40% de toda a energia produzida e 16% de toda a água potável (TRIGUEIRO, 2005). Mais de 26 bilhões de toneladas de concreto novo são utilizados anualmente em todo o mundo, conforme aponta Senaratne et al (2016) MISRA, 2007;CASUCCIO et al, 2008;MIRANDA;ANGULO;CARELI, 2009;RODRIGUES;FUCALE, 2014), como alternativa de viabilidade econômica, técnica e ambiental para mitigação dos impactos advindos dos elevados índices de consumo de matérias-primas e geração de resíduos.…”

Section: Introductionunclassified

Identificação de áreas para implantação de usina de reciclagem de resíduos da construção e demolição com uso de análise multicritério

et al. 2018

View full text Add to dashboard Cite

Resumo A construção civil é responsável por um elevado consumo de recursos naturais e também pela geração de uma grande quantidade de resíduos de construção e de demolição (RCD). Uma alternativa para o gerenciamento sustentável dos RCDs é a reciclagem para uso na própria construção civil, o que permite a redução da demanda de recursos naturais e dos custos, além de amenizar o impacto gerado pela disposição inadequada desses resíduos no meio ambiente. Diante desse cenário, o presente trabalho tem como objetivo analisar e selecionar áreas para a implantação de uma usina de reciclagem de RCD no Município de Viçosa, MG. Foram utilizadas técnicas de sistemas de informações geográficas (SIG) que permitiram avaliar áreas alternativas por meio da aplicação da análise multicritério, tendo sido selecionadas 23 áreas possíveis para implementação da unidade. A análise complementar com visitação in loco permitiu a seleção de 4 áreas consideradas mais adequadas por apresentarem acesso facilitado, baixos valores imobiliários, ausência de edificações ou uso futuro predefinido. A metodologia adotada se mostrou apropriada para auxiliar na tomada de decisão e na diminuição do tempo necessário para a escolha de áreas destinadas à reciclagem de RCD, podendo ser replicada em outros municípios.

show abstract

Use of aggregates from recycled construction and demolition waste in concrete

Cited by 686 publications

References 21 publications

Limiting properties in the characterisation of mixed recycled aggregates for use in the manufacture of concrete

Limiting properties in the characterisation of mixed recycled aggregates for use in the manufacture of concrete

Durability Assessment of Recycled Concrete Aggregates for Use in New Concrete Phase II

Identificação de áreas para implantação de usina de reciclagem de resíduos da construção e demolição com uso de análise multicritério

Contact Info

Product

Resources

About