Common signs of concrete cancer include cracking, crumbling, or flaking of concrete, rust spots or bubbles on concrete or cement plaster, and leaks in the ceiling and walls. Concrete cancer occurs when steel reinforcement inside a concrete slab begins to rust. As steel oxidizes, it expands and displaces the surrounding concrete, causing it to become brittle and crack, compounding the problem. There are some telltale signs of a particular cancer, and the most obvious is chipping.
But already before visible cracks form, concrete crumbling, internal wall leaks, expanding walls, concrete bubbling, and rust spots can tell you what is happening inside the walls. So how can you detect if your building has concrete cancer? One of the first telltale signs is the presence of ferrous stains on the concrete surface. If the steel rusts inside the concrete, rusty water can purge the steel to the surface, leaving brown spots on the surface. If corrosion has advanced to the point where the steel is expanding, it will usually begin to cause the concrete to crack or break (known as chipped concrete).
The resistivity test is completely non-destructive and gives us an indication of the condition of the concrete structure and the degree of chloride (salt) contamination. When we measure the resistivity of concrete, we determine if the concrete structure is corroding and at what speed. This can be a very useful test, especially when combined with the half-cell potential test to locate potential areas of concrete corrosion. This concrete beam down to a balcony in Drummoyne featured reinforcing bars placed too close to the surface, triggering corrosion that ruptured the concrete. The only sure way to distinguish between specific cancer and something less of a concern is to organize a professional inspection.
Even if flooding is only occasional, it still becomes a problem, as there may be small pockets of moisture hidden in the cracks and crevices that continue to consume the concrete. With something as serious as specific cancer, you'll want to be absolutely sure that it's being done correctly. Once the underlying steel and concrete have been repaired, you will need to cure them properly with specialized coatings. Flat concrete roofs are particularly vulnerable to leaks and water-driven concrete cancer if they are not properly waterproofed. There are many different ways in which concrete can wear out over time, so it's extremely important to know what to watch for and who to call when specific cancer screening is needed. You can be assured of quality workmanship and a specialized solution that covers structural remediation of concrete, steel or wood.
The particular cancer can be especially difficult to detect where a concerted effort has been made to hide or disguise it. This is because Diamond Cut Concrete offers a 24-hour customer service line and can provide you with a quote in one day. If you suspect that your building has been affected by concrete cancer, be sure to have it checked by a professional (such as repair site builders or waterproofing contractors) to find out what type of repair work needs to be done. Unfortunately, this awareness of the durability of concrete and the risk of corrosion is something that the construction industry did not understand so well in past decades. In these cases, the metal structure inside the concrete begins to oxidize, which triggers a chain reaction. Depending on the cause of the concrete cancer, the structural engineer may recommend different solutions.