Slab jacking is a specialized technique used in structure repair works to lift and level sunken or settled concrete slabs. This method is commonly used in situations where the ground beneath the slab has shifted or settled, causing the slab to become uneven and unstable. The process of slab jacking involves drilling small holes in the affected area of the concrete slab and then injecting a specialized grout mixture underneath the slab. This grout mixture is typically composed of a combination of cement, sand, and other additives, and is designed to fill any voids or spaces beneath the slab. As the grout mixture is injected, it expands and exerts pressure on the underside of the slab, effectively lifting it back to its original position. Once the slab is level, the holes in the concrete are filled with a sealant to prevent any water or debris from entering. This method is relatively quick and cost-effective, as it can be completed in a matter of hours or days, depending on the size of the project. Additionally, slab jacking is environmentally friendly, as it does not require the removal and replacement of the entire slab.