Title: Effect of Chemical Admixtures on the Rheology of Fresh Concrete During Vibration

Author(s): S. Kakuta and T. Kojima

Publication: Symposium Paper

Volume: 119

Issue:

Appears on pages(s): 189-208

Keywords: admixtures; air-entraining agents; consistency tests; fresh concretes; plasticizers; plastics, polymers and resins; pore water pressure; rheological properties; Materials Research

DOI: 10.14359/2468

Date: 9/1/1989

Abstract:
The rheological properties of fresh concrete were studied with three types of mixes containing a superplasticizer, an air-entraining agent, or a soluble polymer. A rotating fan-type rheometer with a table vibrator at the bottom of the container was used for studying the rheological properties of concrete under vibration. The acceleration and the pore water pressure of concrete were also determined. Although the flow curves of these mixes without vibration were of Bingham type, with vibration, they behaved as a Newtonian or a non-Newtonian fluid. The effect of admixtures under vibration could, therefore, be determined by rheological parameters such as coefficient of viscosity or a non-Newtonian power number. The flowing behavior of concrete was related to the pore water pressure and the acceleration. The excess pore water pressure was affected by the type of admixture. High pore water pressure resulted in concrete containing the soluble polymer.