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This article, the second of three in a series that examine the use of rheology to measure fresh concrete workability, focuses on the rheological design of concrete production equipment and admixtures.

However, it is difficult to market these products' true impact on concrete to customers who are familiar only with the slump test as the standard workability measurement.

Several manufacturers of twin-shaft plant mixers market them by stressing their products' positive impact on concrete workability using terms such as fluidization and homogeneity, necessary since no rheological parameters for workability are yet part of accepted industry standards.

Leading admixture manufacturers have incorporated rheology into their product development also. Perhaps the best example of rheologically designed admixtures is the development of products that produce self-consolidating or self-compacting concrete. These new-generation admixtures produce a super-fluidifying effect that gives fresh concrete excellent flowability, enables compaction by gravity, and eliminates the need for vibration.

The industry is clearly moving toward designing, developing, and, now, even producing applications in which rheology is playing a critical role. As the emphasis on higher technology only increases, the best the industry can hope for is that the standards organizations can keep pace.