The Wason Medal for Materials Research is bestowed on the author(s) of a peer-reviewed American Concrete Institute (ACI) Materials Journal paper published by ACI that makes extraordinary contributions or impact on the state of knowledge of cement-based materials used in the construction industry. This award was bestowed on Dr. Keshav Bharadwaj (Assistant Professor in Civil Engineering in IISc), Prof. Burkan Isgor, and Prof. Jason Weiss for the paper titled “Pozzolanic Reactivity of Supplementary Cementitious Materials,” published in July 2023. As the concrete industry moves towards its goal of lowering the carbon emissions associated with construction, the number and types of supplementary cementitious materials (SCMs) that can be used in concrete is increasing. Thus, there is a need to quantify the reactivity of traditional and novel SCMs for their appropriate use in concrete. Most recent methods to assess pozzolanic reactivity of SCMs are based on measuring certain outputs such as heat release (Q), calcium hydroxide (CH) consumption, and non-evaporable water. This paper describes an approach to quantify the maximum degree of reactivity (DOR*) of SCMs using thermodynamic modelling to aid in the interpretation of these tests. It is shown that the outputs of the reactivity tests should be interpreted based on the SCM type (i.e., based on the chemistry of the SCM, as described by ASTM/AASHTO). The paper proposes an interpretation for commercial SCMs to directly quantify the DOR* from the Q and CH consumed. The DOR* is a performance indicator for the SCM (i.e., it is the fraction of the SCM that can react in concrete), and an input to models to predict the performance of concrete.
“Pozzolanic Reactivity of Supplementary Cementitious Materials,” published in the July 2023 issue of the ACI Materials Journal, pp. 63-76.
