Self-compacting recycled concrete: Relationships between empirical and rheological parameters and proposal of a workability box

• Published in: Construction & building materials Vol. 143; pp. 537 - 546
• Main Authors: Iris, Gonzalez-Taboada, Belen, Gonzalez-Fonteboa, Fernando, Martinez-Abella, Diego, Carro-Lopez
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.07.2017; Elsevier B.V
• Subjects: Analysis; Cements (Building materials); Concretes; Empirical parameters; Mechanical properties; Recycled coarse aggregate; Rheological parameters; Self-compacting concrete; Workability box; United States; Self-compacting concrete; Recycled coarse aggregate; Empirical parameters; Rheological parameters; Workability box
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.03.156

•Rheology and workability of self-compacting recycled concrete (SCRC) were analysed.•Relationships between different empirical parameters were obtained for SCRC.•The suitability of usual empirical limits for SCRC was discussed.•Relationships between empirical and rheological parameters were also studied.•A workability box and its time-dependent evolution is proposed for SCRC. An only suitable type of self-compacting recycled concrete (SCRC) for all applications does not exist, as happens with conventional self-compacting concrete (SCC). An experimental program was carried out to evaluate workability and rheology of 49 mixes of self-compacting concrete made replacing the natural coarse aggregate by recycled concrete coarse aggregate. Workability responses included the slump flow, L-box, J-Ring and sieve segregation tests. The suitability of the limits fixed with these tests for the usual applications in SCC was discussed for SCRC. Rheological responses included the stress growth and flow curve tests. Both workability and rheological responses were compared to indicate relationships between them and in order to observe if they follow the same trend in SCRC as in conventional SCC. Finally, a workability box was proposed to describe recommended combinations of both static yield stress and plastic viscosity for SCRC at 15min from the cement-water contact, taking into account the fulfilment of several workability limits. Also, a second box was defined at 45min to describe the time-dependent evolution of the first one.