41. Structuration rate of fresh SCC: influence of the state of shear during rest

Title: 41. Structuration rate of fresh SCC: influence of the state of shear during rest
Author(s): G. Ovarlez, N. Roussel
Paper category : conference
Book title: 5th International RILEM Symposium on Self-Compacting Concrete
Editor(s): G. De Schutter and V. Boel
Print-ISBN: 978-2-35158-047-9
e-ISBN: 978-2-35158-088-2
Publisher: RILEM Publications SARL
Publication year: 2007
Pages: 285 - 290
Total Pages: 6
Nb references: 13
Language: English

Abstract: Between the two aspects of thixotropy of fresh SCC (structuration at rest and destructuration under flow), understanding and measuring the first one is far more important in terms of potential applications (pressure formwork, multi-layer casting and SCC stability...):
in these cases, concrete is indeed at rest and what really matters is the increase of its apparent yield stress with the time of rest. However, the measurement of the structuration rate of a given thixotropic SCC is very delicate; there exist several methods, which may give different results. We show here that this measurement is more complicated than what was initially imagined. We present results that show that the structuration rate of cementitious materials does depend on the shear stress at flow stoppage and during rest: the higher this stress, the higher the yield stress.

Online publication: 2009-06-16
Publication type : full_text
Public price (Euros): 0.00