Dr Sam Ghazizadeh

Overall, my research aims to understand and control the properties of cements so that we can design them to perform particular functions for us. My current research interests are:

Mechanisms of cements hydration: cements react with water via a process called hydration. The rate by which cements hydrate can vary significantly from one cement to another. The rate of hydration is always of high technological importance; in some cases, we need cements that harden quickly whereas it is sometimes desirable to have cements with low reactivity. My interest here is to understand how different cements react with water molecules, what processes control the rate of reactions (i.e. rate controlling step), and how we can control those processes to suit our purpose. My current focus is to build up a picture of how various cements, especially iron containing constituents of Portland cements as well as slags activated with near-neutral salts, react with water alone or in the presence of other chemicals. The knowledge will help design cements for specific applications, such as waste immobilisation or digital fabrication of concrete.

Thermodynamics of cements: thermodynamics has long been central to cement science where it has been applied to study a variety of phenomena. The last few years have seen a growing interest in using thermodynamic methods to model reactions surrounding cements hydration and clinkering in kilns. However, it is fairly complex to model these processes partly due to the lack of required thermodynamic data. My research interest is to measure thermodynamic properties of cement hydrates and clinker minerals and test the accuracy of those measurements using theoretical models.

Cement toolbox: cements are the most widely used type of materials, so much so that we often take them for granted. However, in one way or another, we cannot continue using the cements we use today. This is partly because: (i) we are running out of natural resources that are suitable and readily available to use for producing cement; (ii) the carbon footprint associated with the production of some cements, such as Portland cement, is high; (iii) we need cements that could immobilise toxic wastes produced from various industries; (iv) the construction industry is fast advancing with the growing need of cements with particular functionalities (the good example of this is 3D printing concrete which requires specific binders with controlled setting and fluidity). Therefore, we need more than ever to have a toolbox of various cementitious materials that does one or more particular functions for us. The overall aim of my research is to synthesise cements of various chemical and mineralogical compositions, understand their chemical and physical properties as they react with water over time.