A cost-effective method to assess the fiber content and orientation in steel fiber reinforced concrete

Steel fiber reinforced concrete (SFRC) is a widely used construction material in the modern civil and building engineering. When steel fibers are incorporated into a concrete matrix, significant improvement in the mechanical behavior with respect to the parent plain concrete can be obtained. Several researches have shown that the mechanical performance of SRFC strongly depends not only on the fiber content, but also on the orientation in the concrete mixture with respect to the applied stress. Therefore, measuring these parameters, especially on-site, is a goal of the utmost importance. As a matter of fact, non-destructive measurements are preferable and the cost of these tests should be as cheap as possible. In this paper, a cost-efficient, hand-held measurement device is presented. It is based on a magnetic probe, which is very sensitive to ferromagnetic material such as steel fiber. First, the working principle of the measurement method is discussed. Then, the experiment validation of this device as well as the comparison with a previously developed reference device are reported.