AASHTO R 81-17 (2021) PDF Download

AASHTO R 81-17 (2021) is a standard practice that outlines the procedures for evaluating the static segregation resistance of self-consolidating concrete (SCC) cylinders after they have hardened. The standard defines SCC as a type of concrete that is capable of flowing to fill formwork completely, even in the presence of congested reinforcement, without the need for mechanical consolidation.

The purpose of this standard is to provide a method for assessing the stability of SCC by evaluating its resistance to static segregation. Static segregation refers to the separation of coarse aggregates from the mortar matrix during the casting, transportation, or consolidation processes. This can lead to an uneven distribution of ingredients and compromise the overall performance and durability of the concrete.

The standard describes the test procedure, equipment requirements, and specimen preparation techniques for conducting static segregation tests on hardened SCC cylinders. It provides guidelines for measuring and evaluating the segregation resistance of SCC using visual observations, such as the determination of the height difference between the top and bottom surfaces of the cylinder specimen and the estimation of the visual area of segregation.