PRECAST REINFORCED CONCRETE PILES

PRECAST REINFORCED CONCRETE PILES
Precast reinforced concrete piles are constructed of conventional reinforced concrete with internal reinforcement consisting of a cage made up of longitudinal bars and lateral or tie steel. The piles are usually in the form of square with sections ranging form about 250 mm to about 450 mm and a maximum section length of up to about 20 m. For the reason of saving weight, long piles would manufacture with a hollow interior in hexagonal, octagonal or circular sections. Maximum allowable axial load is up to about 1000 kN. The lengths of pile sections are often dictated by practical considerations.
The use of the main longitudinal bars is provided to prevent the bending moments induced when the pile is lifted from its casting to the stacking area. On the other hand, lateral steel in the form of hoops and links resist shattering or splitting of the pile during driving.
Sometimes, it may be necessary to extend the pile by casting a length on to it in-situ . In such situations, the concrete at the top of the original pile should be stripped to expose 200 mm of the reinforcement. The new longitudinal reinforcement is then joined to the original reinforcement by full penetration butt weld.
Where welding is not practical, the original longitudinal reinforcement should be exposed to a distance of 40 times the bar diameter, and the new reinforcement overlapped for this length. The extension is then cast in-situ. Also, it can use epoxy mortar with dowels to connect the piles.