Overview

Rheological measurements are often performed using a rotational rheometer. In this type of rheometer, the tested fluid is sheared between two surfaces, one of which is rotating [1]. Usually, the angular velocity is imposed and the response of the material is monitored by the measurement of the torque. The manufacturers recommend the use of a standard oil of known viscosity to verify that the instrument is operating correctly. Because these oils are expensive, however, they cannot be used for the large volumes employed in concrete rheometers. Therefore, a relatively inexpensive, accurate reference material is needed that incorporates aggregates for concrete rheometers. As concrete and mortar are non-Newtonian, the reference material should also be non-Newtonian. The development of this new Standard Reference Material (SRM) is based on a multiphase approach. This report is the description of the development and certification of a paste SRM. Based on this SRM, further SRMs for mortar and concrete will be developed in the future. The purpose of this report is to describe the process to certify SRM 2492, a "Bingham Paste Mixture for Rheological Measurements". All measurements used for the development of the rheological characteristics are provided along with statistical analyses.