At CSC Services, we specialise in applying protective concrete coatings that minimise the deterioration of concrete. Properly applied, a concrete coating can stop the deterioration of concrete before it progresses to reinforcing steel. Protection of this rebar is essential for the long-term durability of any concrete structure.
This article gives you a visual guide as to the stages of concrete deterioration.
As exposed reinforcing steel, rust staining and spalled concrete are all clear signs of the loss of structural strength, a visual scale of deterioration can be used. Here are some of the key factors to look out for and why.
At the start of the deterioration process, concrete may look nearly new. If acid attack has occurred, the deteriorated concrete can however be chipped easily.
With initial surface deterioration, some exposed aggregate will be present.
Exposed aggregate will be widespread with advanced surface deterioration. There is likely to be moderate cracking too.
As deterioration continues, pH levels of the concrete surrounding the reinforcing steel lowers, and rusting and spalling occurs, exposing the rebar. Rust staining will be evident and there will be significant cracking too. Hammer testing is widely used to identify rebar corrosion below the surface. Concrete that sounds hollow when struck may indicate a void.
At the far end of the deterioration scale, there will be widespread exposed aggregate. In addition, advanced surface deterioration with reinforcing deterioration can also be evident through widespread cracks and rust staining.
Coating deterioration concrete is possible but it is considerably more difficult than applying concrete coatings to new concrete. To do this effectively, a contractor will need to consider the extent of deterioration and substrate condition. There are a range of tools available to assess this, but a contractor must understand the deterioration process to specify the optimum remedial solution.
Following the assessment of the concrete condition, the refurbishment solution can be specified. Typically, concrete coatings or epoxy mortars are used to rebuild the concrete surface.
CSC Services have many years of experience installing cementitious coatings to reinstate concrete cover. There are a range of different coating products available depending on substrate compatibility, lifespan and the film thickness required to provide the necessary cover.
We will often specify a waterborne, cementitious modified polymer coating. A 2mm coating is equivalent to 100mm of good quality concrete cover, and provides a complete barrier to water under 10 bar pressure. being cement based, it chemically reacts with the substrate to form an integral part and will have a design life equivalent to that of the concrete to which it is applied.
Not only does this high performance cementitious coating reinstate cover, it provides structures with additional protection against freeze/thaw cycles, de-icing salts, water and chloride ion penetration, ensuring that the life span of the structure is both achieved and extended.
Give us a call today on 0191 410 3444 for more information about concrete repairs or concrete coatings.