Evolution of the thermal expansion coefficient of UHPC incorporating very fine fly ash and metakaolin

Title: Evolution of the thermal expansion coefficient of UHPC incorporating very fine fly ash and metakaolin
Author(s): Stéphanie Staquet, Bernard Espion
Paper category : conference
Book title: International RILEM Symposium on Concrete Science and Engineering: A Tribute to Arnon Bentur
Editor(s): J. Weiss, K. Kovler, J. Marchand, and S. Mindess
Print-ISBN: None
e-ISBN: 2912143926
Publisher: RILEM Publications SARL
Publication year: 2004
Nb references: 8
Language: English

Abstract: This research focuses on the development of the autogenous shrinkage of UHPC since casting time. One of the purposes of this research was to analyse the possibility to substitute the silica fume normally used in UHPC by another pozzolan in order to minimize the autogenous shrinkage. Three optimal mix proportions were tested: the first one was based on the Reactive Powder Concrete mix proportion; 2/3 of the silica fume used in RPC was replaced by a very fine fly ash coming from South Africa in the second one and by a metakaolin in the third one. For each mix proportion, the evolution of the activation energy in function of the concrete strength was determined as well as the thermal expansion coefficient. Two different cures were applied: at 20°C or a heat cure at 42°C during two days after casting. The autogenous shrinkage curves were obtained from the measurements after having eliminated the thermal strains. For UHPC cured at 20°C, the mix proportion containing metakaolin shows an autogenous shrinkage significantly lower than the other mix proportions. For UHPC cured at 42°C, the total shrinkage measured for the mix proportion containing metakaolin is negligible by comparison with the others mix proportions.

Online publication: 2004-03-25
Classification: Driving Forces
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143926.024