Investigation of non-linear drying shrinkage for end-restrained shotcrete with varying thickness
(English)In: Magazine of Concrete Research, ISSN 0024-9831, E-ISSN 1751-763XArticle in journal (Refereed) Submitted
Tunnels in hard, jointed rock is commonly reinforced with shotcrete (sprayed concrete) applied directly on the irregular rock surface. The thickness for such lining can be as low as 50 mm which result in a fast drying. The resulting shrinkage of the restrained lining is a well known phenomena that causes cracking. Installation of some drainage system also results in an end-restrained shotcrete lining which is more prone to shrinkage cracking. The drying process is a complex problem that depends on multiple factors such as cement content, porosity and conditions of ambient air, i.e. temperature, relative humidity and wind speed. In this paper, two numerical models capable of capturing the structural effects of drying shrinkage was compared. Results shows that inclusion of non-linear drying shrinkage is important to accurately describe crack initiation in a end-restrained shotcrete slab. Best fit to experimental data was obtained when the rate of drying was described as a non-linear decreasing function.
Drying shrinkage, cracking, shotcrete, varying thickness, rock support
Research subject Civil and Architectural Engineering
IdentifiersURN: urn:nbn:se:kth:diva-205309OAI: oai:DiVA.org:kth-205309DiVA: diva2:1088430
FunderRock Engineering Research Foundation (BeFo)
QC 201704182017-04-122017-04-122017-04-19Bibliographically approved