Tremie concrete for special geotechnical works – a story about performance and sustainability.

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Abstract

When far more than 50 years ago the first standards on concrete and tremie concrete have been written concrete technology was quite simple. A blend of Portland cement and aggregates mixed with enough, but not too much water. Bored Piles or D-Walls had not been 100 m deep at that time though.
Modern concrete is much more complex, which would allow to rate it also “high-performance” concrete. To specify the necessary criteria that are essential for a successful placement of concrete under submerged conditions in today’s structures is a challenge. A joint task group of EFFC and DFI (European Federation of Foundation Contractors and Deep Foundation Institute) have brought together experts from the industry but also from consultants to find a common understanding on what good practice would be to construct high-quality cast in-situ concrete elements in the ground. 2016 a first edition of the Guideline to Tremie Guide for Deep Foundations has been released and was followed by an edition 2 in 2018 that considered findings from an academic lab and field research study, executed by scientific experts from Missouri and Munich technical universities.
The group has decided to revise and update the Tremie Guide again, and a third edition shall be released by end of 2024. Sustainability has been identified being one of the extra topics to cover. It’s believed that based on a performance-based concept to design concrete, all options can be used to materialize a low-carbon concrete without diminishing quality aspects that also govern sustainability. Eventually, all stakeholders must work together to adopt new, or revised regulations to concrete – like in a future part 3 of the concrete standard EN 206 – leading to more reliable control of performance and for sustainability. Future approaches may be founded on lessons learned from numerical modelling which is a key to better understand the complex interactions governing concrete flow mechanisms.

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Short Curriculum

Karsten Beckhaus, Dr.-Ing., has been involved in the Deep Foundation Industry for 21 years and has been working in the structural engineering business for more than 30 years.  Karsten obtained his University degree in Civil Engineering, and later his doctoral degree, from the Technical University in Munich, Germany.  He is now member of the management board of BAUER Spezialtiefbau GmbH and responsible for the Quality Management and the Technical Support division which assists Bauer’s projects worldwide, in specialist technical consulting, design, logistics and equipment tasks. Karsten also works on sustainability and standardization, amongst others for standards on design and execution of special geotechnical works. Since 2014, Karsten chairs the joint Concrete Task Group of EFFC and DFI. He’s also chairman of the Working Group for revision of European Norms for the Execution of Bored Piles and Diaphragm Walls, ie EN 1536 and EN 1538.