Study of ASR in concrete with recycled aggregates: Influence of aggregate reactivity potential and cement type

• Published in: Construction & building materials Vol. 265; p. 120743
• Main Authors: Barreto Santos, Miguel, de Brito, Jorge, Santos Silva, António, Hasan Ahmed, Hawreen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.12.2020
• Subjects: Alkali-silica reaction; Concrete; Degradation; Durability; Recycled aggregates; AMBT; ASR; CPT; Recycled aggregates; Durability; w/c; ITZ; RA; SC; Degradation; NAC; CRA; NA; RAC; CNA; FNA; Concrete; Alkali-silica reaction
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2020.120743

•Alkali-silica reaction was analysed through expansion evolution in concrete mixes.•Different replacement levels of coarse natural aggregates.•Reactive and non-reactive coarse recycled aggregates.•The influence of cement type was also evaluated. The incorporation of recycled aggregate (RA) in structural concrete requires deep knowledge of this material’s potential and limitations by assessing its effect on the concrete properties. Alkali-silica reaction (ASR) is one of the most concerning degradation agents in concrete produced with natural aggregates, and more expectedly in recycled aggregate concrete (RAC), which motivated this study. ASR was analysed through expansion evolution in concrete mixes produced with different replacement levels of coarse natural aggregates (CNA) with reactive and non-reactive coarse recycled aggregates (CRA). In addition, concrete mixes were naturally and artificially aged to simulate the reaction at different ages. The influence of cement type on ASR development in RAC was also evaluated. The results showed that the incorporation of 20% of reactive RA did not affect concrete’s expansion behaviour. The highest expansions were obtained when 100% of reactive RA and a higher strength class cement were used.