Correlating slump, slump flow, vebe and flow tests to rheological parameters of high-performance concrete

Abstract

Conventional single-point workability tests continue to be used for specification and quality control of concrete despite their inherent limitations. These tests cannot characterize workability of concrete in terms of fundamental rheological parameters. Attempt has therefore been made to correlate slump, slump flow, slump flow time, percent flow and Vebe time to rheological parameters of high-performance concrete. Thirty numbers of concrete mixes without steel fibers and with steel fibers of specific dose have been considered during experiment. It has been observed that rheological parameters can be correlated to slump and slump flow. In case of fiber reinforced concrete, there is a decrease in percent flow with the increase in rheological parameters. Vebe time, however, remains unchanged up to yield stress 500 Pa and plastic viscosity 40 Pa.s beyond which it steeply increases with further increase in yield stress and plastic viscosity. Flow test may be a better test for FRC as it is sensitive over all ranges of workability of concrete.

Keywords

• rheology
• slump
• slump flow
• vebe time
• flow