Why Does Concrete Sink?
Sidewalks and driveways alike can be an common place for trips and falls as a result of uneven or broken concrete. Concrete is heavy, and when the soil foundations underneath the cement naturally settle incorrectly. Concrete raising and mudjacking services are designed to repair the sunken concrete, without the cost or effort of replacing it. We’ve identified the main causes of outdoor concrete that sinks.
How Exactly Does Concrete Sink?
Soil Shrinkage, Compaction & Settling
Underneath the concrete that is laid on the ground, is various types and levels of soils. Each type of soil has different load-bearing capacities, which leads to compaction and settling after unspecified periods of time. Soil that contains large amounts of clay or silt will shrink when it gets dry, creating more room beneath the concrete slab, and making it susceptible to sinking. Unsupported slabs will sink as a result of soil beneath the concrete slabs that settles and compacts, making the slab susceptible to cracking and uneven surfaces.
Washout of Soils
As general rainfall and water activity takes place, water moves underneath the concrete slabs. It can wash away the soil that supports the weight of the concrete, creating void or empty space in the foundation beneath the slab. The empty space can lead to sinking, breaking or caving of the concrete slab.
Sometimes concrete is poured over a flat, sufficient soil foundation, and other times it is not. Whether the foundation beneath the concrete was quality to begin with or not, over time the soil moves, shrinks, and settles, creating voids that allow sinking and breakage. Concrete raising and mudjacking are common solutions in fixing an insufficient soil foundation. By pumping grout and soil mixtures or polyurethane foam materials into small holes in the concrete, insufficient foundations are a quick fix for contractors who perform slabjacking.
Concrete sinks for a variety of reasons, but the common problem is always soil. Whether it’s good soils, bad soil, dry soil, or moved soil, the foundation that concrete sits on is what will determine how it shifts or falls over time.