A novel magnetic approach to improve compressive strength and magnetization of concrete containing nano silica and steel fibers

Abstract

Novel exploratory research was conducted on the utilization of a new method to optimize the magnetic effect on the compressive strength of concrete specimens containing nano silica and steel fibers. According to the results of previous experiments, this research investigated the compressive strength of 7- and 28-day concrete with different amounts of nano silica and steel fiber in the non-magnetized mode and also after applying the innovative Pre-Post technique (applying both pre- and post-magnetization modes to a specimen), on the other hand, the magnetic susceptibility of this type of concrete was also investigated by increasing the magnetic flux density by 1 T, which was not investigated in previous studies. Based on this, it was proved that adding nano silica of up to 10 % as a substitute for cement and 1 % of steel fiber, increases the compressive strength by 88.79 % and 59.69 % in 7- and 28-day specimens respectively, as well as increasing the magnetic flux density is positively related to the compressive strength of specimens, meaning that with the increasing of this parameter up to 1 T, the compressive strength also enhanced by 152.26 % and 114.03 % for specimens containing 10 % nano silica and 1 % steel fibers in 7- and 28-day specimens respectively, in addition of this, it was evaluated that the rate of increment of the compressive strength in the 7-day specimens was higher than the 28-day ones. Using the results of this experiment, it is noteworthy that adopting the presented pre-post technique in addition to improving the performance of pre-magnetized concrete containing fiber in smart structures equipped with electromagnetic systems, can compensate for the negative effects of using large amounts of additives such as nano silica substituted with cement on compressive strength.