Robustness of Low-Binder SCC (Eco-SCC), Lean SCC, and Binder-Rich SCC

Author(s): Florian V. Mueller, Olafur H. Wallevik, Kamal H. Khayat
Paper category: Conference
Book Title: 8th International RILEM Symposium on Self-Compacting Concrete - SCC 2016
Editor: Kamal H. Khayat
ISBN: 978-2-35158-156-8
e-ISBN: 978-2-35158-157-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 25-34
Total Pages: 10
Language: English

Abstract: Preliminary studies on robustness of Self-Consolidating Concrete (SCC) indicate sensitivity to water content and superplasticizer (SP) dosage. The robustness is of particular interest in the concept of Eco-SCC. Such concrete utilizes a relatively high volumetric water-to-powder ratio (VW/VP) to ensure sufficient lubricant volume, which causes a relatively low plastic viscosity. This parameter is commonly considered as the governing property of a mixture to ensure adequate stability. Tests were carried out on representative mixtures of low-binder SCC (referred to as Eco-SCC), Lean SCC (according to definitions in [1]), and a conventional SCC, considered as “binder-rich”. The approach is to alter the water content by ±5 and ±10 l/m3, and the SP dosage by ±10 % and ±20 %. A rheology approach is used, and the hardened concrete properties are evaluated, including a recently developed homogeneity test. The tests reveal a robustness area (RA) for Eco-SCC that is not only relatively small but also advantageously positioned in a rheograph which allows a clear identification of its self-consolidating status. For the binder-rich SCC, the rheological properties covered a relatively wide range of parameters commonly attributed to SCC, although, in fact, the homogeneity assessment revealed unconsolidating mixtures, stable SCC, and mixtures with considerable increased risk of segregation. In a conventional SCC, not only does the altered water content result in considerable variation of plastic viscosity, therefore affecting both dynamic and static segregation stability, but also the over-saturation with dispersing polymers can reduce the stability.

Online publication: 2016
Publication Type: full_text
Public price (Euros): 0.00