131. Thixotropy-enhancing agents for stabilization of SCC and earth moist concrete

Title: 131. Thixotropy-enhancing agents for stabilization of SCC and earth moist concrete
Author(s): J. Terpstra
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: 869 - 874
Total Pages: 6
Nb references: 5
Language: English

Abstract: Stabilizing admixtures are applied in order to increase the stability and predictability of the properties of self-compacting concrete (SCC). Usually, stabilizing admixtures increase the plastic viscosity of the concrete and are therefore called viscosity enhancing agents. However, stability and robustness can also be obtained by applying a starch-based thixotropy-enhancing agent. In this way a stable and low viscous SCC is obtained with outstanding filling and flowing (even self-levelling) properties.
For self-compacting lightweight concrete (SCLWC) stability and water management can be even more critical than for ‘normal weight’ SCC. Therefore, the mechanism of thixotropic enhancement was investigated in a lightweight paste using a starch-based stabilizer. From the large effects on yield value and thixotropy it is concluded that the thixotropy-enhancing mechanism also introduces stability in the case of SCLWC. This will facilitate practical application of SCLWC by increasing workability and pumpability.
Compaction and stability are also very important for earth moist concrete. In this case stability means dimension stability after immediate demoulding. The dimension stability is governed by the green strength of the concrete. A starch-based thixotropy-enhancing agent was applied in order to increase the green strength. This allowed for an improved compaction and increased strength development of the concrete.

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