Evaluation of the Protective Effect of a Nanoscale Deep Penetration Sealer in Improving Chloride Erosion Resistance of Concrete

In this study, the protective effect of a Nanoscale Deep Penetration Sealer (NDPS) in improving the chloride erosion resistance of concrete was evaluated and the influence of water-cement ratio (<i>w</i>/<i>c</i>) and the NDPS spray volume on the protective effect was explored, in order to gain a deeper insight into the effect of NDPS on the durability of concrete in chloride environments. The thickness of the protective layer formed by NDPS within the concrete was determined and the effectiveness of this protective layer was verified. Based on the determination of the ability of NDPS to form a protective layer in concrete, the diffusion laws of chloride in concrete at different <i>w</i>/<i>c</i> and NDPS spray volumes were investigated, and a prediction model was established. The results show that NDPS forms a 2-3 cm protective layer in concrete to resist chloride penetration, which is nearly as thick as the concrete cover. The protective layer weakens the capillary absorption of concrete and prevents the penetration of aggressive substances into the concrete. NDPS significantly improves the chloride erosion resistance of concrete. The chloride diffusion coefficient of concrete with a <i>w</i>/<i>c</i> ratio of 0.6 was reduced by approximately 35% after being sprayed with 1000 mL/m² of NDPS, and the protective effect strengthens with increasing spray volume at a fixed <i>w</i>/<i>c</i> and weakens with decreasing <i>w</i>/<i>c</i> at a fixed NDPS spray volume. The proposed predictive model is the basis for predicting the diffusion of chloride in concrete with NDPS protection in practical engineering applications and provides a guide for the application of NDPS in practical engineering.