Concrete is the most widely used building material globally, but its porous structure makes it susceptible to corrosion from moisture, chloride ions, and carbon dioxide, leading to problems such as steel reinforcement corrosion and carbonation cracking. In recent years, methyltrimethoxysilane, as a highly efficient penetrating protective agent, has been increasingly applied to the long-term protection of critical infrastructure such as bridges, tunnels, and seaports.

Unlike film-forming coatings, methyltrimethoxysilane can penetrate deep into the capillary pores of concrete (up to several millimeters), hydrolyzing and condensing on the pore walls to form a hydrophobic siloxane network. This network does not clog the pores, preserving the concrete's "breathability," while effectively blocking the intrusion of liquid water and harmful ions. Experiments show that the water absorption rate of treated concrete can be reduced by more than 80%, and its resistance to freeze-thaw cycles is significantly improved.

It is worth noting that methyltrimethoxysilane is fluorine-free and solvent-free, making it more environmentally friendly than many traditional waterproofing agents. Although it releases a small amount of methanol, this evaporates rapidly in open environments, and its impact on construction workers is controllable. Currently, several European and Chinese standards (such as JT/T 986-2015) have listed it as a recommended concrete protective material. With the increasing popularity of the "century-long project" concept, this "invisible protection" technology is safeguarding the durability of infrastructure.