Title: In Situ Test to Determine Fiber Content of Steel Fiber Reinforced Concrete by an Electro-Magnetic Method

Author(s): Taketo Uomoto and Kazusuke Kobayashi

Publication: Symposium Paper

Volume: 82

Issue:

Appears on pages(s): 673-688

Keywords: electromagnetic testing; fiber reinforced concretes; fresh concretes; hardened concretes; metal fibers; nondestructive --

DOI: 10.14359/6579

Date: 9/1/1984

Abstract:
To control the quality of steel fiber reinforced con-determination of fiber content is one of the most important matters in practice. Although SFRC is often assumed to be satisfactorily mixed by any concrete mixer, uniform fiber content can not always be obtained if mix proportions and mixer design are unsuitable. To deal with the problem of nonuniform fiber a simple in-situ test is needed to check the quality of SFRC before it is cast. Determination of the fiber content of SFRC can be accomplished by using techniques such as X-ray image analysis, separation by washout analysis, and an electro-magnetic method. However, some of these techniques are too troublesome to be used as in-situ The special electro-magnetic method described herein is not only applicable to hardened concrete but also to fresh concrete. Measurement of fiber content can be done within a few minutes whether the test is performed in the laboratory or on the job. The proposed method of measuring fiber content is discussed from the point of view of practical problems such as the effects of distribution and orientation of fibers, etc.. This method has been introduced as a standard test of SFRC in Japan.