Title: Portable Vane Test to Assess Structural Buildup at Rest of Self-Consolidating Concrete

Author(s): Ahmed F. Omran, Siwar Naji, and Kamal H. Khayat

Publication: Materials Journal

Volume: 108

Issue: 6

Appears on pages(s): 628-637

Keywords: Portable vane test; self-consolidating concrete; static yield stress; structural buildup at rest; thixotropy.

DOI: 10.14359/51683466

Date: 11/1/2011

Abstract:
In the case of casting deep elements, self-consolidating concrete (SCC) should be designed with high thixotropy to reduce lateral pressure on the formwork system and with low thixotropy in multilayer casting to avoid the formation of a weak interface between successive lifts. Therefore, thixotropy determination of SCC on site may be necessary. Thixotropy can be determined by evaluating the rate of structural buildup at rest. Quality control of SCC on site necessitates the use of a simple, robust, and inexpensive test. A field-oriented test (portable vane device) Enabling the evaluation of the structural buildup at rest of concrete is highlighted in this paper. Relative errors between 4 and 20% are estimated for this device. Good correlations are observed between six indexes of structural buildup determined from the portable vane and concrete rheometer using 60 SCC mixtures. The classification of SCC mixtures according to thixotropic values and the ranking of the six structural buildup indexes are also introduced in this paper.