For about a century slump test have been the only practical mean for assessment of concrete workability. Developed as a tool to control the consistency of concrete production, with the time, mainly due to its simplicity, ‘slump’ has gradually transferred into an important concrete “property”. The problem, however, is that the slump test only provides a partial description of concrete workability, the one that closely relat- ed to yield stress in rheological terms. What is missing and cannot be reliably assessed by the slump and any other simple tests is plastic viscosity. The combination of the two main rheological properties: yield stress and plastic viscosity offers a large spectrum of fresh concrete characteristics. Understanding and controlling them 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 factor in concrete supply chain and also an important element of contractual and legal obligations. Rheology of concrete is no longer the destiny of scientists, but there are still significant challenges to overcome before rheology finds its most deserved place in concrete construction sites.
CBE Consultancy Ltd
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