Structural Behavior of Reinforced Fibrous Concrete Beams Incorporating Nano Silicon Dioxide Powder

Abstract

This research investigated the combined effect of nano-silicon dioxide (NSD) and steel fibers (SF) on the structural behavior of reinforced concrete beams. Eight specimens were tested: four without SF and four with SF, with varying NSD percentages (1%, 2%, and 3%) replacing cement. The study examined the mechanical properties of concrete and structural behavior outputs, including load-deflection, ductility, and damage patterns. Results indicate that NSD significantly enhances compressive strength, with increases of 8.7%, 25.2%, and 32.5% for 1%, 2%, and 3% NSD, respectively. Combined with SF, there are additional improvements in tensile and flexural strengths, leading to higher load capacity and reduced deflection. Beams with 1% steel fibers showed a 30% higher load capacity compared with those without fibers. The ACI code was found to underestimate the load capacity of beams with NSD and SF, indicating the need for updated equations. While NSD increased concrete brittleness, SF enhanced ductility and energy absorption. Future research should focus on optimizing NSD and SF dosages, studying long-term durability, and validating findings through large-scale tests.