【国外标准】 Standard Test Method for Time of Flow of Fiber-Reinforced Concrete Through Inverted Slump Cone (Withdrawn 2008)

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.1.1 This test method covers the determination of the inverted slump-cone time of fiber-reinforced concrete, both in the laboratory and in the field. 1.2 This test method is considered applicable to freshly mixed concrete having coarse aggregate up to 1 1/2 in. (38 mm) in size. It is not applicable to concrete that flows freely through the cone. 1.3 The values stated in inch-pound units are to be regarded as the standard. SI units are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.