Studying the Hydration of Cement Systems in Real-time Using Quasielastic and Inelastic Neutron Scattering

The metamorphosis from the mostly crystalline, multiphase cement powder to the amorphous/crystalline mixture that forms the world's most important building material is dependent on the transformation processes during hydration. Understanding these hydration processes is perhaps the most important aim of cement research and quasielastic neutron scattering (QENS) excels in the study of the time-resolved hydration of cementitious systems, by revealing detailed information on the motions of hydrogen and state of water in the mixture, allowing insights into the hydration process to be gained that are unrivalled by other techniques of analysis. This chapter covers the applications of both QENS and inelastic neutron scattering (INS) to cement research. Cement and its constituent components, their hydration, and the importance of kinetics are introduced. Common research tools for the study of cement hydration are briefly outlined, before focus is shifted to QENS and INS. The different methods of applying QENS and INS to cementitious systems and the parameters derived from these that describe the system and the progression of the hydration reaction are outlined. The hydration kinetics, as revealed through the time-evolution of these parameters, is discussed. In the final section, case studies of cement research using QENS and INS are presented.