Fresh concrete can exhibit different rheological behavior when at rest than when flowing. This difference is due to thixotropy, which can have important consequences for formwork pressure, multi-lift casting, slip-form paving, pumping, and segregation resistance. This TechNote defines thixotropy and distinguishes it from other changes in rheological properties; discusses the origins of, test methods for measuring, and factors affecting thixotropy; and concludes with its applications.
Keywords: aggregate segregation; formwork pressure; plastic viscosity; pumpability; rheology; rheometer; static yield stress; thixotropy; yield stress.
TechNotes are a committee document that are narrowly focused, single-topic guides, usually practice oriented, that present a specific direction on a particular issue. ACI committee documents (including TechNotes) are reviewed and approved by ACI's Technical Activities Committee.
Table of Contents
Description of thixotropy
Origins of thixotropy
Effects of concrete materials and temperature on thixotropy
Applications of thixotropy
Referenced standards and reports
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