Abstract
Much has been learned in recent years about the rheology of cement paste and how it relates to microstructure. Such progress has been made possible in part by the use of specialized instruments for measuring dynamic rheological properties, developed to characterize viscoelastic materials. This paper reviews recent studies of cement paste in our laboratory in which dynamic rheological properties are used to follow the effects of cement hydration. Not as much has been learned about the rheology of concrete. Measuring flow behavior of concrete presents interesting challenges; concrete rheometers have been developed, but they are not widely used. It appears likely that concrete rheology is controlled by rheology of its paste, although such links have not yet been directly established. This paper also presents preliminary results from our laboratory on concrete flow behavior. Concrete rheology provides important information about its workability, and rheological parameters have important advantages over slump when characterizing workability.