Post-tensioned slabs contain a tendon, or steel cable, that runs crisscrossed throughout the center of the slab. Once the poured concrete dries, the post-tensioned cables are stretched and tightened, which applies a significant force to the concrete slab. This technique strengthens and compresses the concrete, which helps reduce cracking and structural instability.   The post-tensioning process helps residential homes and commercial buildings achieve greater load-bearing strength. Post-tension slabs are more durable and stable than traditional concrete slabs that lack the reinforcement of steel cables.