| Abstract: |
The design of concrete with specified properties for an application is not a new science, but it has taken on a new meaning with the wide use of special concretes, such as self compacting concrete (SCC). General terms such as flow under its own weight and filling capacity , or workability, flowability, compactibility, stability, finishability, pumpability, and/or consistency are currently used interchangeably without a definition based on fundamental measurements of properties. Several attempts have been made to better relate fresh concrete properties with measurable quantities. Some researchers treated fresh concrete as a fluid and used fluid rheology methods to describe concrete flow. This approach, the most fundamental one, is reviewed in this paper. The main topics that will be addressed are: 1) Review the fundamental definitions of quantities used to uniquely describe the flow of concrete; 2) Give an overview of the tests that are commonly used to measure the rheology of fresh concrete, partially based also on the completed comparison of concrete rheometers sponsored by ACI; 3) Discuss challenges left to resolve to bring rheology to the construction site. A conclusion will present some thoughts on research needed. |
