Inverted Slump Cone Test for Fiber Reinforced Concrete 

This test method provides a measure of the consistency and workability of fiber-reinforced concrete.
The inverted slump-cone time is a better indicator than slump of the appropriate level of workability for fiber-reinforced concrete placed by vibration because such concrete can exhibit very low slump due to the presence of the fibers and still be easily consolidated. Mixtures with a time of flow less than 8 s, or with a slump greater than 2 in. (50 mm) shall be evaluated in terms of slump because the time of flow is too short to determine with satisfactory precision, or may not be determinable because the fiber-reinforced concrete flows freely through the inverted cone.
The results may be used for mixture proportioning, quality control both in the laboratory and in the field, and in development and research.
The results obtained using this test method may be influenced by vibrator diameter, amplitude, and frequency.
This test method may not be applicable to some concretes reinforced with fibers flexible and long enough to wrap around the vibrating element and dampen vibration.