Mechanical and durability study of nano-SiO2 and nano-TiO2 on fiber reinforced concrete

This work presents the results of an experimental investigation into the strength and durability properties of fiber-reinforced concretes that have polypropylene (PP) fibers added to the concrete by volume and nano-SiO2 (silicon dioxide) and nano-TiO2 (titanium dioxide) used as partial substitutes for cement. Nano-SiO2 and nano-TiO2 particles used ranged in size from 40 nm to 400 nm. The specimens were cast using cement blended nano-SiO2 and nano-TiO2 percentages of 1%, 2%, 3%, and 4% by weight of cement. M55 grade concrete was employed for the casting process. The addition of PP fibers to the concrete was 0.5% by volume. The specimens underwent a battery of mechanical tests, including microstructural testing, compression testing, split tensile strength testing, and rupture modulus testing. Furthermore, tests for durability factors such as porosity, sorptivity, and degradation were conducted, and the findings are presented. Flexural strength of 2% nano-SiO2 or nano-TiO2 increased by 8.09% and 6.89% and porosity decreased by 16.13% and 13.92% with respect to the reference concrete. By comparing the outcomes, it was shown that the inclusion of 0.5% PP fibers and 2% nano-SiO2 or nano-TiO2 improved the mechanical qualities, but this was followed by a decrease in strength. The findings demonstrated that 2% nano-SiO2 combined with 0.5% PP fiber had a greater mechanical strength than 2% nano-TiO2.