A prestressed concrete pile is a type of deep foundation element made of concrete in which internal stresses are intentionally introduced before any external loads are applied. These stresses are created by tensioning high-strength steel tendons within the concrete to counteract the stresses that will result from service loads.
| Feature | Reinforced Concrete (RC) Piles | Prestressed Concrete (PC) Piles |
|---|---|---|
| Definition | Concrete piles with standard steel reinforcement (rebars) | Concrete piles with prestressed steel tendons |
| Type of Reinforcement | Mild steel rebars (passive) | High-tensile steel strands/wires (actively tensioned before casting) |
| Pre-tension or Post-tension | No prestressing involved | Prestressing applied (usually pre-tensioned) |
| Crack Resistance | Moderate – may crack under high tension | High – designed to resist tensile stresses and cracking |
| Load Capacity | Lower load capacity per unit | Higher load capacity (for same cross-section) |
| Durability | More prone to cracking and corrosion if not protected | Better resistance to corrosion due to tight, crack-free concrete |
| Length & Slenderness | Generally shorter or thicker | Can be made longer and more slender |
| Fabrication Method | Simple casting with rebars | Requires tensioning equipment and more precise control |
| Cost | Generally cheaper to produce | More expensive due to prestressing steel and process |
| Usage | Small to medium structures, buildings, short-span bridges | Large buildings, high-rise foundations, marine structures, long-span bridges |
| Common Shape | Square or circular cross-sections | Mostly spun (circular) or square precast piles |
Material: High-strength concrete and high-tensile steel tendons.
Shape: Typically square, rectangular, circular, or octagonal cross-sections.
Length: Can be precast in standard lengths and joined to reach the required depth.
Prestressing Method:
Pretensioned: Tendons are tensioned before casting the concrete.
Post-tensioned: Tendons are tensioned after the concrete has hardened (less common for piles)
