ACI 238.2T-14 PDF Download

ACI 238.2T-14 is a standard that focuses on the concept of concrete thixotropy. Thixotropy refers to the difference in rheological behavior of fresh concrete when it is at rest compared to when it is flowing. This standard aims to provide a comprehensive understanding of thixotropy and its implications in various concrete construction applications such as formwork pressure, multi-lift casting, slip-form paving, pumping, and segregation resistance.

The standard begins by defining thixotropy and differentiating it from other changes in rheological properties. It then delves into the origins of thixotropy and presents various test methods for measuring this property of concrete. These test methods are crucial in evaluating the thixotropic behavior of fresh concrete and understanding how it may vary under different conditions.

The standard also discusses the factors that can affect thixotropy, such as mix composition, temperature, and shear rate. Understanding these factors is essential for effectively managing and controlling thixotropy during the concrete placement process.

Finally, the standard explores the practical applications of thixotropy in concrete construction. It highlights how the knowledge of thixotropy can be utilized to optimize formwork pressure, improve casting techniques, enhance concrete pumping, and minimize the risk of segregation.