Elastoplastic Modelling of an In Situ Concrete Spalling Experiment Using the Ottosen Failure Criterion

An in situ concrete spalling experiment will be carried out in the ONKALO rock characterization facility. The purpose is to establish the failure strength of a thin concrete liner on prestressed rock surface, when the stress states in both rock and concrete are increased by heating. A cylindrical ho...

Full description

Saved in:
Bibliographic Details
Main Authors: Lauri Kalle Tapio Uotinen, Topias Kalle Aleksi Siren
Format: Article
Language:English
Published: Wiley 2017-01-01
Series:Journal of Engineering
Online Access:http://dx.doi.org/10.1155/2017/4723017
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An in situ concrete spalling experiment will be carried out in the ONKALO rock characterization facility. The purpose is to establish the failure strength of a thin concrete liner on prestressed rock surface, when the stress states in both rock and concrete are increased by heating. A cylindrical hole 1.5 m in diameter and 7.2 m in depth is reinforced with a 40 mm thin concrete liner from level −3 m down. Eight 6 m long 4 kW electrical heaters are installed around the hole 1 m away. The experiment setup is described and results from predictive numerical modelling are shown. Elastoplastic modelling using the Ottosen failure criterion predicts damage initiation on week 5 and the concrete ultimate strain limit of 0.0035 is exceeded on week 10. The support pressure generated by the liner is 3.2 MPa and the tangential stress of rock is reduced by −33%. In 2D fracture mechanical simulations, the support pressure is 3 MPa and small localized damage occurs after week 3 and damage process slowly continues during week 9 of the heating period. In conclusion, external heating is a potent way of inducing damage and thin concrete liner significantly reduces the amount of damage.
ISSN:2314-4904
2314-4912