The strenuous job of planning a reinforced concrete structure doesn’t end after your project is complete. Concrete structures can be exposed to elements like salt water, CO2 and chloride, which can penetrate the concrete all the way to the steel reinforcement, resulting in corrosion. If corrosion is not properly monitored and managed, the durability of the structure begins to weaken, which has serious safety risks. The risks and rate of corrosion increases the longer a building, bridge, or dam is around, so it is especially important to test and maintain them when needed.
Cracks in Concrete
A lot of corrosion can go completely unnoticed. Often, if you see corrosion, it is too late for simple repairs, and rebuilding may be necessary. However, sometimes non-structural cracks may appear, which may not pose any safety risks at first. Although not immediately dangerous, there are a couple of reasons you might want to repair these cracks. The first reason is simply that they make the structure look unsafe and unattractive. The second reason is that these cracks can begin to act as pathways to the reinforcement, making it even easier for destructive elements to corrode your rebar. For these reasons, it is valuable to repair these cracks with your preferred method.
How to Repair Concrete
There are lots of methods to repair concrete, so take care to choose the right technique for the problem at hand. Here are five methods to repair cracks that can help prevent corrosion and improve appearances:
- Epoxy Injections
- Routing and Sealing
- Stitching the Cracks
- Drilling and Plugging
- Grouting Methods (with Portland cement or dry packing)
It is important to keep in mind the objective you have for repairing the crack. For more serious cracks or deep corrosion, you may need to consider other methods. The methods listed above can help provide water tightness, improve durability, and prevent the spread of a corrosive environment. By understanding the end goal, you can determine the right choice for repair.
Tools to Identify Corrosion Patterns
At this point, you may be wondering how you can accurately identify corrosion patterns and cracks in your concrete structure. While you can see and solve non-structural cracks simply by looking at the concrete, it can be difficult to ensure that there is, in fact, no structural damage occurring. Further, there may be underlying issues that can go completely unnoticed. Therefore, it is important to properly test either the corrosion potentials or the corrosion rate of the rebar. Giatec offers two NDT solutions for this:XCell™ and iCOR®.
XCell is a tablet-based NDT probe for fast and accurate detection and on-site analysis of corrosion in reinforced structures. The device measures the corrosion potential and sends it wirelessly to a tablet for generating half-cell contour plots in real-time.
iCOR is a non-destructive tool that uses our patented CEPRA technology to estimate the corrosion rate without having to physically connect to the rebar. This high precision device provides details of the corrosion rate mapping of rebar, corrosion potential mapping of rebar, in-situ electrical resistivity of concrete, and ambient temperature and relative humidity. It can perform all of these functions with no connection to reinforcement, but by adding this connection iCOR is also capable of performing the half-cell potential test.
Both iCOR and XCell can help you identify corrosion, which is critical to know before beginning concrete repair. To prevent major issues, corrosion tests should be performed regularly. The tool you choose may depend on requirements you are given, ease of use, or simply preference. At the end of the day, iCOR and XCell are both excellent choices to accurately understand and assess corrosion.