Concrete Repair Systems
As part of our range of structural repair systems, Timberwise are also able to assist with problems relating to damaged concrete.
What causes damage to concrete?
There are several key issues that can cause damage to concrete. These are:
Due to the porous nature of concrete, carbon dioxide in the air can penetrate into it causing damage. The soluble alkalis and calcium hydroxide give concrete a PH of around 12.5 and when carbonation begins the calcium hydroxide reacts with the carbon dioxide which in turn lowers the pH of the concrete and this can leave it at risk of deterioration.
Carbonation starts on the surface of the concrete, but over time it penetrates into the pores of the concrete causing deterioration, although this doesn’t happen if the concrete is fully submerged in water. The carbonation process can have a detrimental impact on the protection that once existed for the steel bar, and that makes the material very susceptible to corrosion. Once the carbonation process begins the protective environment which once existed for the steel bar is reduced allowing it to be susceptible to corrosion in the event that any moisture is found.
Natural aggregates, water and salt all cause chlorides to be released into the concrete and these can lead to the accelerated corrosion of the steel bars in areas where this occurs.
Freeze & Thaw
During cold temperatures, water that enters into the porous areas of the concrete can freeze. This can cause it to expand and put additional outward pressure on the material.
Properties in the aggregates and cement can cause a chemical reaction and this can result in a breakdown of the concrete.
The solution to damaged concrete: Surveying and testing concrete
The technique for testing concrete prior to a concrete repair is basic:
- Inspecting the concrete visually.
- Using a metal hammer to tap the surface. Sub-surface deterioration will give a lower-pitched “hollow” sound compared to a high-pitched sound given by a good quality concrete.
- Low-level voltage can be produced by corrosion. As a result, half-cell testing is conducted on the reinforcing steel to reveal the electrical potential.
- Depth of carbonation, chloride content, core sample testing and compressive strength are all tested and conducted.
The Timberwise Concrete Repair System
The lightweight base coat comes as one polymer modified mortar component which features excellent bonding properties. With this particular product you don’t need corrosion protection or a bonding coat. A one component lightweight finishing mortar makes up the finish.
Benefits of the Timberwise Concrete Repair System:
- Reliable and easy application.
- No risk of confusion with two individual products.
- No protection coat or bonding.
- Concrete is protected against carbonation.
- Tested and approved.
- Saves time.
- Reduces scaffolding times.