Shrinkage cracking of thin irregular shotcrete shells using multiphysics models

• Shotcrete (sprayed concrete) is commonly used to support tunnels in good quality hard rock. Including a drainage system often results in end-restrained sections of shotcrete, which have created problems with shrinkage induced cracking. In this paper a multi-physical material model with coupled behaviour between thermal actions, moisture transportation and mechanical strain has been used to model and describe the complex behaviour and effects of shrinkage of such a structure. The model was first calibrated against a free shrinkage test and then used to simulate an experimental set-up for testing of end-restrained shrinkage. The first results lead to a need of tuning of the parameters controlling the drying of the shotcrete to accurately describe the experimental results. This tuning could be an indication that the shrinkage behaviour differs between a restrained and an un-restrained sample. However, further research about possible changes in the pore structure as well as more detailed measurements of the early shrinkage behaviour is needed before any such conclusions can be drawn.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Infrastrukturteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Infrastructure Engineering (hsv//eng)

Keyword

Cracking

Fibre Reinforced Shotcrete

Multi-physics

Shrinkage

Byggvetenskap

Civil and Architectural Engineering

Publication and Content Type

ref (subject category)

kon (subject category)