What causes a concrete slab to sink?
Concrete is hard to beat as a construction material for all kinds of load-bearing surfaces, from driveways and sidewalks to floors, roads, and airport runways. However, concrete has two characteristics that can cause problems: it’s heavy and it’s brittle.
The weight of a concrete slab can sometimes cause the soil beneath the slab to compress. When this happens, all or part of the concrete slab will sink down under its own weight, often cracking in the process. The cracking occurs because concrete isn’t a resilient material. If a slab is unevenly supported, it’s likely to crack because it can’t stretch or bend.
In addition to unsightly cracks, slab settlement problems can also result in potential accidents, poor drainage, tripping hazards and expensive property damage.
Level or Fill
Big lifting power through small holes. To lift a settled concrete slab with PolyLevel®, 5/8″ diameter holes are drilled through the slab. After an injector port is screwed into each hole, a special nozzle mixes two reactive materials and sprays the expanding mixture beneath the slab. The PolyLevel product is lightweight, high capacity and waterproof.
For void filling, Low Density Cellular Concrete (LDCC) may be the right solution. Compared to standard concrete which is a dense, heavy material – cellular concrete is relatively light. Cellular concrete is made by replacing the stone aggregate used in standard concrete with air bubbles. These tiny bubbles are created by blending foaming agents into the concrete during the mixing process. LDCC is lightweight, strong and self-leveling.
Seal the Cracks
At Thrasher Commercial, we use a silicone-based crack and joint sealer developed by our sister company, Supportworks, called NexusPro. It offers a long-lasting and durable solution that will keep moisture from seeping beneath your concrete, where it can cause further problems. When we install NexusPro, we prepare and clean the concrete cracks, install the product and then finish it off with native sand to give the whole surface a clean, finished look.
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