German Guide to Tremie Concrete for Deep Foundations, 2nd Edition - Leitfaden Kontraktorbetonfür Tiefgründungen, Zweite Fassung-PDF

PDF

Pdf Summary

The 2018 second edition of the EFFC/DFI Guide to Tremie Concrete for Deep Foundations provides practical recommendations for designing, specifying, testing, producing, and placing concrete in bored piles and diaphragm walls. It supplements—not replaces—applicable standards and project requirements, and is not itself a standard.<br /><br />The guide emphasizes that successful construction depends on balancing fresh-concrete workability, retention of workability, and stability. Concrete must flow around reinforcement and fill the excavation under its own weight while resisting blockage, segregation, bleeding, and filtration. The guide recommends assessing flow using slump-flow diameter, slump-flow velocity, and visual stability, supplemented by tests for workability retention and stability where project conditions warrant. Suggested acceptance ranges include a slump flow of 400–550 mm and slump-flow velocity of 10–50 mm/s; criteria should be selected for each project.<br /><br />Concrete mix design should account for available materials, reinforcement layout, aggregate grading, admixtures, temperature, transport, and placement duration. Trial mixes and, where appropriate, full-scale field trials help confirm performance. Production controls should verify material moisture, water content, batching, mixing, and delivery consistency.<br /><br />Design and construction details are equally important. The guide recommends adequate reinforcement spacing and concrete cover to allow flow, careful cleaning of excavations, sealed tremie pipes, appropriate pipe spacing and embedment, and uninterrupted placement wherever possible. Placement records should track concrete levels, volumes, and pipe embedment.<br /><br />Quality assurance should combine fresh-concrete testing with informed assessment of the completed structure. Imperfections are not automatically defects; their significance depends on their effect on capacity and durability. Non-destructive tests, direct inspection, and expert interpretation may be needed. Large-scale trials and numerical modelling can help identify risks and refine project-specific procedures.

Keywords

Tremie concrete

Deep foundations

Bored piles

Diaphragm walls

Fresh concrete workability

Slump flow

Mix design

Construction quality assurance

Placement records

Non-destructive testing