ASTM C1611:21 pdf free download – Standard Test Method for Slump Flow of Self-Consolidating Concrete.
11.2 Single-Operalor Precision—The single-operator precision statement reflects the use of both procedures A and B. The single-operator standard deviation for slump flow has been found to be 27 mm 11.1 in.J (see Note 4) for mixtures having slump flow values between approximately 4X0 and 680 mm [19 and 27 in.1. Therefore, results of two properly conducted tests by the same operator on the same hatch of concrete should not difler by more than 75 mm [3.0 in.] (see Note 4).
X 1.1 The flow rate of a self-consolidating Concrete mixture is influenced by its viscosity. Hence, for the purpose of developing a self-consolidating concrete mixture in the laboratory, a relative measure of viscosity is useful. When periorming the slump flow test, the time it takes [or the outer edge of the concrete mass, to reach a diameter of 5(X) mm [20 in.] from the time (he mold is first raised, provides a relative measure of the unconfined flow rate of the concrete mixture. For similar materials, this time period, termed T0, gives an indication of the relative viscosity of the selfconsolidating concrete mixture.
Nori XI. 1— The T, alue can provide intiwmation on the flow properties of thc self-consolidating conerctc mixture. whereby longer valucs normally correspond to increased viscosity. Special high-range water-reducing admixtures are typically used o modify the flow properties of the self-consolidating concrete mixture. In addition, viscosity- modifying admixtures and other changes in mixture proportions and materials can also influence flow properties and resistance to segregation.