Shrinkage and durability of shotcrete
2010 (English)In: Shotcrete: Elements of a system. PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE ON ENGINEERING DEVELOPMENTS IN SHOTCRETE, QUEENSTOWN, NEW ZEALAND, 15–17 MARCH 201 / [ed] E. Stefan Bernard, London: Taylor & Francis Group, 2010, 173-180 p.Conference paper (Other academic)
Cracking of shotcrete in tunnels has in recent years become a problem in Sweden. Thusan investigation was initiated. The results show that shotcrete differs from of ordinary cast concrete inmany ways. Basically, wet shotcrete is ordinary concrete but is mixed with a set accelerator at the nozzleand as a result the major cement reactions will take place in a stiff (but not hardened) material. Cementhydration results in shrinkage that in ordinary concrete will be compensated for due to settlement, but inthe stiffened shotcrete it will change the properties of the concrete. It will give a different structure andmode of porosity, which in turn will increase shrinkage. Especially with an alkali free set accelerator theshotcrete develops a larger amount and coarser porosity, which in turn will generate significantly largerdrying shrinkage than in cast concrete. Moreover, the shotcrete is very sensitive to early shrinkage if notproperly water cured. Water must be added to compensate for the chemical shrinkage in the stiff but nothard structure of the young shotcrete.
Place, publisher, year, edition, pages
London: Taylor & Francis Group, 2010. 173-180 p.
IdentifiersURN: urn:nbn:se:kth:diva-80372DOI: 10.1201/b10545-21ScopusID: 2-s2.0-84861062950ISBN: 978-0-415-47589-1OAI: oai:DiVA.org:kth-80372DiVA: diva2:496243
Third international conference on engineering developments in shotcrete, Queenstown, New Zealand, 15-17 March 2010
QC 201204102012-02-092012-02-092012-04-10Bibliographically approved