Experimental study on mechanical behaviour and gas permeability of New-to-Old concrete bonding

Author(s): M. Choinska, A. Pertué, A. Fabien, A. Khelidj
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1549- 1557
Total Pages: 8
Language: English

Casting new concrete directly on an old concrete may occur for short range casting or for repair, which includes the presence of a bonding surface between the new and the old concrete. The objective of this study is to characterize the mechanical behaviour and gas permeability of the bonding.

The tests are performed on cylindrical concrete specimens using two configurations of casting in order to get lengthwise and inclined specimens. Mechanical study consists in a uniaxial compression test and a shear one. Permeability study is carried out on the lengthwise specimens. All the tests have been performed using concrete at different ages to get new-toold concrete bondings and reference concretes without bonding.

The results emphasize a significant decrease in compressive strength of the inclined specimens and a slighter decrease of the lengthwise ones. The latter is affected by an important shear strength loss. In fact, the bonding appears as the weak zone and affects the overall specimen behaviour: cracking appear at the bond for any specimen type or type of loading. Concerning gas pemeability tests, the first results show an important increase of the intrinsic one for new-to-old concrete bondings and therefore highlight the impact of a bonding on durability of concrete structures.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00

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