Post Tensioned Slab Over view

Post tensioning is a technique for reinforcing concrete. Post-tensioning tendons, which are prestressing steel cables inside plastic ducts or sleeves, are positioned in the forms before the concrete is placed. Afterwards, once the concrete has gained strength but before the service loads are applied, the cables are pulled tight, or tensioned, and anchored against the outer edges of the concrete. Post-tensioning is a form of prestressing. Prestressing simply means that the steel is stressed (pulled or tensioned) before the concrete has to support the service loads. Most precast, prestressed concrete is actually pre-tensioned-the steel is pulled before the concrete is poured. Post-tensioned concrete means that the concrete is poured and then the tension is applied-but it is still stressed before the loads are applied so it is still prestressed.

Benefits of PT Slab

• Reduced Cost— Reduction in dead loads due to thinner slabs
• Flexibility in design/ Flexibility in providing service ducts and false ceilings.
• Lesser usage of materials
• Durability-Freezing & Thawing durability is higher.
• Stronger/ more efficient
• Minimizes and controls cracking
• Faster Installation / Shoring and formwork can be removed as soon as the tendons are stressed.
• Elimination of shrinkage cracking/ No joints or fewer joints
• Slabs and other structural members become thinner
• Allows construction on expansive or soft soils
• Design of longer spans in elevated members like floors & beams
• Greater Headroom
• Neat & Simplified layout
• Less number of work force engaged than RCC slabs.
• Reduction in the overall building weight/ reduction on the foundation load