Cracking analysis of massive concrete with large-diameter pipes during construction: Fid-Bau Portal

Cracking analysis of massive concrete with large-diameter pipes during construction

Wang, Dong-bo / Song, Xiao-bin / Nie, Hai-yang

Highlights • We conducted on-site full scale test of massive concrete block with embedded large pipes. • We developed and verified a FEM model with consideration of time-dependent mechanical and thermal properties of early age concrete. • We proposed design suggestions for edge distance and spacing of large pipes for prevention of concrete cracking.

Abstract This paper presented the results of a study on the cracking behavior of early age massive concrete with large-diameter pipes during construction. Material property tests were conducted to identify the time-dependent mechanical properties of the early age concrete made of P.O. 42.5 cement. A full-scale reinforced concrete block of $4.4 \times 4.8 \times 3 m$ with pipes up to 508 mm in diameter was cast and monitored for the development of the temperature and strain of concrete. A three-dimensional FEM model was established based on user defined subroutine for the time-dependent mechanical and creep properties. The FEM model was verified based on the test results and was used for cracking risk analysis of massive concrete with different pipe layouts. It is found that a diameter to edge distance ratio or a diameter to spacing ratio of no more than 1/3 is sufficient to prevent additional cracking risk of concrete due to the presence of pipes.