For just about a century the only practical mean to reliably assess workability of concrete was very well known concrete slump test. Developed as a tool to control the concrete production and supply consistency (uniformity), with the time, 'slump' has gradually transferred into an important concrete "property". The problem, however, is that the slump test gives only partial description of concrete workability, the one closely related to yield stress. What is missing and cannot be reliably assessed by the slump test is plastic viscosity. The combination of the two properties: yield stress and plastic viscosity provides a large spectrum of fresh concrete performance criteria. Understanding and controlling these two fundamental fresh concrete properties allow for designing more economical and better performing concrete mixes, designing more complex concrete structures and improving concrete construction processes. Concrete fresh properties (workability) check and verification will remain the most vital quality control component in the concrete supply chain and also an important element of contractual and legal obligations. Reliability and simplicity of yield stress and plastic viscosity measurement methods is another important issue, since they determine how well these new test methods will be accepted by the industry. Rheology of concrete is no longer the destiny of scientists, but there are still significant challenges to overcome before it is fully adopted and used by the concrete industry. The knowledge transfer is one of them.
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