Bridge Protection: Engineering Durability

Why bridges deteriorate

The bridge deck operates in the most aggressive environment of all engineering structures. In summer, its surface heats up (in Ukraine, in August it can reach +85-90°C), in winter it freezes, and together with anti-icing agents, the most dangerous enemy — chlorides — penetrates the concrete. They do not destroy concrete directly. They penetrate through micro-pores to the steel reinforcement and initiate corrosion. Rust expands several times in volume, pushing the concrete from the inside, and the protective layer begins to delaminate. By the time cracks become visible, the process inside has been ongoing for years.

Add to this the constant dynamic load — thousands of transport cycles daily, vibration, temperature deformations when the structure expands and contracts every day. Each cycle opens micro-cracks through which water penetrates deeper. Classic waterproofing, designed for a static structure, fatigues and cracks under such conditions.

Effective bridge protection is not just one coating, but an engineering sequence where each layer of waterproofing performs its function.

First, the concrete itself is restored: repair compounds return the structure's geometry and strength, filling craters and cavities and protecting exposed reinforcement. Next, the surface receives a continuous waterproof membrane that completely cuts off access to water and chlorides. On the roadway, it must withstand what ordinary coatings cannot — traffic movement, braking, abrasion, impact loads, while maintaining elasticity to move with the structure rather than tearing under its deformations.

Special attention is paid to expansion joints and connections. These are the most vulnerable points of any bridge, where the structure 'breathes'. Here, materials capable of stretching and compressing multiple times without losing tightness and adhesion are needed.

Why liquid membrane, applied on-site, is a key technological advantage of modern bridge systems — continuity and seamlessness. Rolled materials have seams, and a seam is always a potential leak point. A liquid membrane, applied directly on-site, forms a seamless coating that replicates any geometry: connections, drainage, edges, complex nodes. It bonds with the substrate over the entire area, so even local damage does not spread under the coating, as it does with rolled systems.

The speed of curing such systems allows for opening traffic in a short time — a critical advantage for bridges that cannot be taken out of service for long.