Cracks in concrete are common and develop when stresses in concrete exceed its strength. Cracks are usually caused by normal concrete shrinkage as it hardens and dries. CSC), as we know it today, was formed in 1958 through the merger of three premixed companies. Although concrete is a very strong building material, it has its limits.
Placing excessive amounts of weight on a concrete slab can cause cracking. When you hear that a concrete mix has a strength of 2000, 3000, 4000, or more than 5000 PSI, it refers to the pounds per square inch that would be needed to crush that concrete slab. Tight cracks are common in concrete slabs. In general, if the crack is stable and does not leak water, it does not indicate a structural problem.
In most cases, these are shrinkage cracks that formed when the concrete cured. Concrete naturally cracks on its own, unless it is given a place to crack, such as a control joint or expansion joint. As concrete cures, heats up and expands. In summer, I saw the slab crack before I could walk on it.
Cracks in concrete are extremely common, but are often misunderstood. When a homeowner sees a crack in their slab or wall, especially if the concrete is relatively new, they automatically assume something is wrong. This is not always the case. Some types of cracks are unavoidable.
The best thing a contractor can do is try to control cracking. This is done by properly preparing the subbase, ensuring that the concrete is not too wet, using reinforcement where needed, and properly placing and spacing the crack control joints and expansion joints. However, cracks sometimes occur despite the precautions taken. The chemical reaction, which causes concrete to move from a liquid or plastic state to a solid state, requires water.
While shrinkage cracks can appear on the surface within hours of pouring concrete, it takes a full month for new concrete to fully settle. I am not familiar with the flooring product you are using, but I would recommend contacting the manufacturer regarding installation over concrete cracks. The key point to understand in relation to cracking is that water is a certain percentage of the concrete mix. If your concrete is a little older, a concrete repair professional can help you fix the cracks.
Concrete Decor is a valuable source of information, ideas, product news and training relevant to commercial and residential work in decorative concrete and related specialties. In general, cracks wider than a credit card and going through the depth of concrete are structural in nature and could be a sign of more serious problems (see Evaluating Concrete Crack Repair). Although aesthetically unattractive, crusting cracks do not present any structural problems, but they can be patched if desired. It is porous and water will seep through the solid concrete and flood the basement if present.
However, proper site preparation and good concrete finishing practices can go a long way in minimizing the occurrence of cracks and producing a more aesthetically pleasing project. When cracks can't be prevented, concrete contractors often use control joints to, well, control where the cracks will end up. This chemical reaction, or hydration, continues to occur for days and weeks after the concrete is poured. We place reinforcing bars in several strategic places to prevent concrete from settling and moving away from the places where it needs to be.
They often use wire mesh as reinforcement, which keeps the concrete pieces together but does not prevent cracking. This means that, as the concrete contracts, steel springs help the concrete contract in the ground it sits on, preventing cracks from forming or, at least, spreading apart. .