Concrete Protection, Waterproofing, and Reinforcement: Sika Guide
Quick answer: reinforced concrete deteriorates through two main pathways: carbonation (CO2 in the air lowers the concrete's pH, so it stops protecting the rebar, which then starts to corrode) and direct chemical attack in industrial environments or tanks. Sika offers anti-carbonation coatings for exposed façades, epoxy coatings for aggressive chemical environments, crystallizing waterproofing mortars, and carbon fiber laminates to structurally reinforce a weakened element.
Protection Against Carbonation (Façades and Outdoor Structures)
Elastic coating with crack-bridging capacity and a lower environmental footprint
Chemical and Industrial Protection
Sikagard®-62 is a solvent-free, two-component epoxy coating for protecting concrete in tanks and industrial facilities exposed to chemical attack, where an acrylic paint would not hold up.
Crystallization Waterproofing
Sika MonoTop®-160 Migrating is a cementitious mortar that migrates through the concrete's capillaries and crystallizes, sealing the structure even against negative water pressure (for example, a basement where water pushes in from outside). It's applied with a brush directly onto damp concrete.
Structural Reinforcement
Sika® CarboDur® E is a pultruded carbon fiber laminate (CFRP) that bonds to a concrete beam or slab to reinforce it against bending, for example when its load capacity has been reduced by corrosion, cracking, or a change in the building's use. Installation requires a specialized technician and a specific structural epoxy adhesive.
How to Choose
Exposed concrete façade or columns subject to the elements: Sikagard-670 W or Sikagard-5500, depending on the finish and environmental sensitivity you're looking for.
Tank, industrial building, or floor exposed to chemicals: Sikagard-62.
Basement or wall with water infiltration from negative pressure: Sika MonoTop-160 Migrating.
A beam or slab that needs more load capacity without increasing its cross-section: Sika CarboDur E, always with a structural technician.
Frequently Asked Questions
What is concrete carbonation?
It's the reaction between CO2 in the air and the lime in concrete, which lowers its pH over time. When that carbonation front reaches the rebar, the steel is no longer protected and starts to corrode, which can cause cracking and spalling.
Does an anti-carbonation coating cover cracks?
Elastic coatings like Sikagard-5500 have crack-bridging capacity for fine cracks, but they don't replace a structural repair if the crack has a mechanical cause or is still active.
Does the crystallization mortar work against pressurized water?
Yes, Sika MonoTop-160 Migrating is formulated specifically to work under negative pressure, that is, when water pushes in from the inaccessible side of the wall or slab.
