The effects of uniform magnetic field on the mechanical and microstructural properties of concrete incorporating steel fibers

This study investigated the effects of applying a uniform magnetic field (UMF) of flux density 500 mili Tesla (mT) to fresh and hardened concrete specimens with steel fibers at volume ratios of 1 and 1.5% on mechanical and microstructural properties. To attain these objectives, compressive and splitting tensile strengths tests were carried out on the specimens with steel fiber-reinforced concrete (SFRC) at 28 days. Furthermore, the microstructure of SFRC, subjected to the UMF, was assessed via scanning electron microscopy (SEM) images. An electromagnetic instrument, capable of generating a density of 500 mT, was used to produce UMF. Finally, a model equation was proposed to predict the splitting tensile strength of SFRC subjected to the UMF as a function of its compressive strength. The application of UMF to SFRC specimens incorporating 1.5% steel fibers revealed an increase in both compressive and splitting tensile strengths up to about 18.2% and 9.5%, respectively. The SEM analysis indicated that the UMF enhanced the cement hydration process, which is responsible for the higher mechanical strength development of SFRC compared to the control specimen.