Carbonation Resistance of Marine Concrete Containing Nano-SiO2 under the Action of Bending Load

In order to study the influence of nanomaterials on carbonation resistance marine concrete under bending loads, an appropriate amount nano-SiO2 was added plain concrete, and a self-developed box loading device were used conduct coupling test. Four different stress levels set measure depth nano-concrete at ages. Scanning electron microscopy (SEM) X-ray diffraction (XRD) analyze interfacial transition zone. The as test index evaluate durability nano-SiO2-based combined action load carbonation. results showed that compressive flexural strengths remarkably improved when concentration 2%. Compared with regular based by 15.5% 15.3%, respectively. When level 0.15 0.6, depths NS20 20.5 18.4% lower than those PC in tensile zone 18.9 23.7% compression 31 3 28 days PC. PC, decreased 50 23.7%, significantly conventional same age. is constant, tension increases gradually increase age, first 7 d 50% days. Under increased increasing levels, while levels. 0.3–0.45, slope curve increased. SEM XRD analysis revealed internal structure reducing width microcracks, number pores, microcracks. C3S/C2S CaCO3 crystals less C-S-H gel more concrete. dosage 2%, its improvement effect most significant.