Quality-test to prove the flow behavior of SCC on site

Title: Quality-test to prove the flow behavior of SCC on site
Author(s): G. Buchenau, B. Hillemeier
Paper category : conference
Book title: International RILEM Symposium on Self-Compacting Concrete
Editor(s): O. Wallevik and I. Nielsson
Print-ISBN: 2-912143-42-X
e-ISBN: 2912143713
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 84 - 93
Total Pages: 10
Nb references: 4
Language: English

Abstract: Self-compacting concrete (SCC) requires a careful control of its flow behavior. Fresh concrete acts as a non-Newtonian fluid. It is insufficient to describe the rheological behavior of non-Newtonian fluids with a conventional one-point workability test. Rheological measurements are essential, to determine the flow behaviour dependent on the shear rate and to modify the mixture with the aim to achieve self-compacting properties. SCC is a suspension consisting of a low concentration of coarse aggregates dispersed in the viscous fluid of a mortar matrix. The fresh concrete properties of SCC are influenced mostly by the rheological properties of the mortar matrix. This paper reviews the possibility to optimize the viscosity of mortar by replacing cement by rock powders, aiming to design SCC with normal strength. In order to continuously verify the capability of self-compaction during a time consuming placing of SCC, the authors developed a rheometer appropriate for steady control as well as on site as in the laboratory. The principle of the measurement is comparable to the well-known falling-ball viscometer. Different from the viscometer the new method evaluates data from an accelerating sphere. The velocity function of the accelerating sphere gives the information to determine the flow curve. The advantages of the new so-called falling-ball rheometer are the short measuring time, the easy handling and the objective documentation with a continuously actualized graph of the flow curve. The most important result is that the robust test method is applicable to determine rheological properties of concrete on site.

Online publication: 2003-08-21
Publication type : abstract_only
Public price (Euros): 0.00