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

The present 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 the mechanical and microstructural properties. To this end, compressive and splitting tensile strength tests were carried out on the specimens with Steel Fiber-Reinforced Concrete (SFRC) on Day 28. Furthermore, the microstructure of SFRC subject to the UMF was assessed using images taken by Scanning Electron Microscopy (SEM). 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 which was subject to the UMF as a function of its compressive strength. 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 UMF enhanced the cement hydration process and it was responsible for the higher mechanical strength development of SFRC than the control specimen.