INVESTIGATION OF THE EFFECT OF HYBRID FIBERS AGAINST ELECTRICAL RESISTANCE AND DYNAMIC RESISTANCE AGAINST CONCRETE EXPLOSION

With the increasing development of concrete structures, properties such as strength and durability of concrete have become particularly important. Therefore, it is necessary to use special concretes and obtain new combinations. Ordinary concrete is brittle and frangible, and if rebar is not used, other materials such as fibers should be added to the mixture to remove the brittleness of the concrete. Fiber is used to control cracks in concrete, which in addition to controlling cracks, improves impact resistance, fatigue, shear, bending, as well as energy absorption of concrete. In this research, fiber concrete made of steel, barchip, and macro synthetic fibers and the combination of each fiber with different volume ratios is subjected to explosive load and the failure rate of each sample and the resistance of fiber concrete with hybrid fibers to explosion have been investigated in laboratory and field. Also, the special electrical resistance of hybrid fiber concrete against the electric current has been evaluated, which can be considered as a measure to evaluate the permeability and parallel absorption of concrete water. The results showed that concrete with macro synthetic fibers had greater explosion resistance than other samples. Also, the electrical resistance of concrete with macro-synthetic fibers has been higher than that of other samples, which will have special applications in corrosive areas with high penetration of chloride ions due to higher electrical resistance and consequently lower permeability. Also, for estimating the cost of fiber performance in concrete, the lowest excess cost of using fibers in concrete was related to the use of 1.5% of the concrete volume of macro synthetic fibers due to the low cost of these fibers and its high resistance to electrical resistance and resistance to explosive load. The use of these fibers in concrete to withstand explosion and electric current has been cost effective.