Preparation of Aligned Steel-Fiber-Reinforced Concrete Using a Magnetic Field Created by the Assembly of Magnetic Pieces

Abstract

In steel-fiber-reinforced composites, when the direction of a steel fiber is parallel to the direction of tensile stress, the capacity of the strengthening and toughening effect of the steel fiber can be fully applied to the composites. In this paper, a method to control the direction of steel fibers from one side surface of the mold full of a fresh mixture of steel-fiber-reinforced concrete using a magnet composed of small magnet squares is proposed, which has the advantage that the approach is suitable for specimens or elements with any size or shape. The influence of the method on the orientation effect of steel fiber is explored, and the flexural properties of the specimens prepared by different orientation methods are compared and analyzed through a three-point bending test. The test results show that the steel fibers in the mixture are successfully aligned by the magnetic treatment and the fiber orientation effective coefficient reaches 0.9 or more. The flexural properties of the aligned steel-fiber-reinforced cementitious composite (ASFRC) prepared by the magnetic device is significantly improved. The test results also show that the properties of the ASFRC prepared by the new method are comparable with that prepared by the previous electromagnetic field in terms of the fiber orientation effective coefficient and flexural strength.

Keywords

• aligned steel fiber
• cementitious composite
• flexure strength
• flexural toughness