Construction methods · Bored piles and deep foundations

Tremie concreting of piles

Concrete for a bored pile is placed through a pipe whose tip stays embedded in the fresh concrete, so the mix displaces the slurry without mixing with it. The mix must flow for hours without segregating; the pour must not stop.

How bridges get built · Bored piles and deep foundations · Tremie concreting of piles

Also called: underwater concrete placement, tremie method, tremie pipe

How it is done

Design a concrete with 180-220 mm slump or a self-compacting mix with retarder for 4-8 hours of workability.
Set the tremie to the base with a plug; start the pour and keep 1-3 m of embedment as the concrete rises; measure the level after every truck.
Withdraw casing as the concrete rises, keeping the concrete head above the outside pressure.
Overpour to bring sound concrete above the cut-off level.

Where it fits

All bored piles and barrettes under slurry or water.

Where it does not

Mixes that stiffen before the pour ends; interrupted supply.

Plant, pace and money

PlantTremie pipes and hoppers, pump or crane and skip, concrete supply of 30-80 m3 per hour.

ProductivityA 60 m3 pile is poured in one to three hours.

CostConcrete at USD 150-250 per m3 plus placement.

Risks and controls

What goes wrong

Tip pulled out of the concrete, cold joints, slurry inclusions, cage floating.

Quality assurance

Pour log with level and volume per truck, slump tests every truck, CSL after 7 days.

Examples

Every bored pile in the game's marine sites.