Principles 5 & 6 - Physical and Chemical Resistance

Concrete structures can be damaged by different types of physical or mechanical attack, including: 

  • Increased mechanical load from increased structure size or equipment
  • Wear and tear from abrasion, such as flooring in a warehouse
  • Hydraulic abrasion from water and water borne solids, such as in treatment or processing plants, or in drainage/sewage channels
  • Surface breakdown from the effects of freeze-thaw cycles in cooler climates

A broad range of chemicals can have adverse on concrete performance with the chemical resistance requirements of a concrete structure typically dependent on the type and concentration of the chemicals, duration of exposure and relative temperatures. 

Appropriate assessment of the risks is a prerequisite to allowing the correct protection strategy to be developed for any specific area. In many situations the design of the best methods of protection will require considerations of both chemical and physical damage, such as mineral processing plants, manufacturing facilities and many more. 

Different types of protective coatings are available from Komerco to provide full range of short and long-term chemical and mechanical resistance, according to the type and degree of exposure. These are based on many different resins and materials including: acrylic, epoxy, polyurethane silicate, epoxy-cement combinations, polymer modified cement mortars and many more. 

In situations where the concrete is already damaged and repair work is required, Komerco can also provide all of the right products to repair these different types of mechanical and physical damage on different types of concrete structure and different climatic and environmental conditions.

An overview of methods to protect and repair alongside potential solutions are outlined below:

Method 5.1 & 6.1 - Coatings - Only reactive coatings are able to provide sufficient additional protection for the concrete to improve its resistance against physical, mechanical or chemical attack.

Method 5.2 & 6.2 - Impregnation - An impregnation is defined as the treatment of concrete to reduce the surface porosity and to strengthen the surface. The pores and capillaries are partly or totally filled.

This type of treatment also usually result in a discontinuous thin film of 10 to 100 microns thickness on the surface. This film serves to block the pore system to aggressive agents to provide additional chemical resistance, or impregnations can react with some of the concrete constituents to result in higher resistance to abrasion and mechanical attack. 

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Method 5.3 & 6.3 - Adding mortar or concrete - The Methods to be used and suitable systems for this are defined in Principle 3 Concrete restoration and the products have to fulfill the requirements of EN 1504-3, Class R4 or R3. In some specific instances products may also need to fulfill additional requirements such as resistance to hydraulic abrasion. To be able to resist a certain level of chemical attack, cement based products need to be formulated with special cements and/or combined with epoxy resins. The engineer must therefore determine these additional requirements on each specific structure.