Certification of SRM 2497: Standard Reference Concrete for Rheological Measurements
Nicos Martys, Max A. Peltz, William L. George, Blaza Toman, Edward J. Garboczi, Chiara Ferraris
Rotational rheometers are commonly used to determine the rheological properties of fluids such as viscosity and yield stress [Fer12]. Manufacturers generally recommend the use of a standard oil of known viscosity to verify that the instrument is operating correctly. These oils are Newtonian fluids and are not representative of the flow of concrete, mortar or paste which behave as a Bingham or power-law fluid. Also, oils are expensive, and would be cost prohibitive because large volumes of the reference material would be needed to calibrate concrete rheometers. Therefore, a relatively inexpensive, well characterized reference material, with properties similar to concrete, e.g., non-Newtonian and incorporates aggregates, similar in dimension to that in concrete for testing in concrete rheometers. The development of this new Standard Reference Material (SRM) is based on a three-step approach. The first step was development of a paste reference material (SRM2492) [liv12], the second step involved creation of the mortar SRM2493 [Oli]. The final step involved development of SRM 2497 which is similar to a concrete material. The purpose of this report is to describe the process used to certify SRM 2497, a Standard Reference Concrete for Rheological Measurements. All measurements used for the development of the rheological characteristics are provided along with statistical analysis. A description of the computational model that was utilized to predict the behavior of the SRM is also provided. The data analyzed in this study serve to certify that the proposed models and values are valid.