EFFC/DFI Guide to Tremie Concrete for Deep Foundations-Paper

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The 2018 second edition of the EFFC/DFI Guide to Tremie Concrete for Deep Foundations incorporates research and numerical modelling completed after the 2016 edition. It provides practical guidance for designing, testing, and placing concrete in bored piles and diaphragm walls, supplementing rather than replacing existing standards.<br /><br />Tremie concrete must flow through reinforcement, fill excavations, displace water or support fluid, and remain stable throughout long pours. Traditional standards mainly use slump or flow limits, but these do not fully describe modern concrete, whose behaviour depends on both yield stress and viscosity. The Guide therefore promotes a performance-based approach that balances workability—the ability to flow and fill—with stability—the resistance to segregation, bleeding, and filtration.<br /><br />Recommendations cover mix composition, aggregate grading, reinforcement spacing, concrete cover, placement practice, and field trials. The Guide advises specifying project-specific target values based on element depth and volume, reinforcement congestion, and expected pour duration. Suggested tests include slump flow, flow velocity, visual stability assessment, and, where needed, tests for workability retention, segregation, bleeding, and filtration. Slump flow and visual stability checks can support routine acceptance testing, while more complex projects may require additional assessment.<br /><br />Numerical modelling can help explain concrete flow and interactions among mix properties, design details, and execution methods, though models require further validation through full-scale trials. Overall, the Guide aims to reduce defects and improve foundation quality by replacing reliance on limited, empirical consistency requirements with measurable performance criteria. It also recommends that these principles inform future revisions of European standards.

Keywords

tremie concrete

deep foundations

bored piles

diaphragm walls

performance-based approach

workability

stability

slump flow

segregation resistance

numerical modelling