143. SCC delayed effects development within a new type of steel-VHPC prebended beam

Title: 143. SCC delayed effects development within a new type of steel-VHPC prebended beam
Author(s): S. Staquet, C. Boulay, L. D’Aloïa, R. Le Roy, F. Toutlemonde
Paper category : conference
Book title: 5th International RILEM Symposium on Self-Compacting Concrete
Editor(s): G. De Schutter and V. Boel
Print-ISBN: 978-2-35158-047-9
e-ISBN: 978-2-35158-088-2
Publisher: RILEM Publications SARL
Publication year: 2007
Pages: 951 - 956
Total Pages: 6
Nb references: 5
Language: English

Abstract: An extensive experimental research has been carried out to extend the technique of prebended composite beams to VHPC. The main advantage of using VHPC instead of C55 concrete is to decrease the prestressing losses of the system thanks to a significant decrease of the creep deformations. As one-step was the casting of two 13m-span beams, it was necessary to use a SCC. Since a risk of cracking at early age due to the transversally restrained shrinkage in the beam was probable and due to the influence of partly restrained longitudinal shrinkage on the composite behavior, the autogenous shrinkage development was examined both under standard isothermal and realistic temperature (same as the beam) conditions. Numerous complementary measurements such as mechanical characterization, creep and shrinkage tests in standard (20°C, 50% RH) and variable ambient conditions were performed. The effects of a realistic temperature history on the VHPC autogenous shrinkage are quantified. With the efforts of mix-design optimization, it could be demonstrated that the creep deformations of this VHPC were reduced by about a factor 2 in comparison with currently used C55 concrete, which made the use of prebending significantly more efficient.

Online publication: 2009-06-16
Publication type : full_text
Public price (Euros): 0.00