ABSTRACT
The execution of bored piles can be challenging in terms of concrete placement. Insufficient concrete cover and entrapment of debris are commonly occurring defects. It is used to be assumed that poor workability of fresh concrete is the main reason. In order to better understand the physical flow processes se-veral laboratory tests with unreinforced and reinforced piles were conducted using coloured concrete. The study of vertical cross sections through the cured piles revealed the flow pattern. Additionally, the flow pattern was modelled in numerical simulations based upon Computational Fluid Dynamics (CFD). For unreinforced piles the numerical simulations show—in good accordance with the physical experiments—that the fresh concrete rises approximately uniformly over the full cross section. In contrast, the reinforced piles reveal a deviant flow behaviour with a shell-shaped structure around the tremie pipe. Hence a new insight is gained about the spreading of fresh concrete in bored piles.
