PROPERTIES OF CARBON-STEEL AND POLYPROPYLENE-STEEL HYBRID FIBER CONCRETE IN LOW-VOLUME FRACTION RANGE

This paper deals with trial testing on concrete reinforced by different combinations of carbon-steel, polypropylene-steel or steel-hybrid fibers in the low volume content range to ensure high electrical resistivity of the fiber concrete. Optimum reinforcement composition is obtained for (compression, splitting tension, and flexural) strength testing conditions and for post-peak behavior. The effect of various measures adopted to promote uniform fiber distribution are assessed by impedance measurements. During the testing program, fiber distribution is checked by microscopy and SEM.