An overview of the mechanism of shrinkage reducing admixtures in mitigating volume changes in fresh and hardened cementitious systems at early ages

Title: An overview of the mechanism of shrinkage reducing admixtures in mitigating volume changes in fresh and hardened cementitious systems at early ages
Author(s): G. Sant, P. Lura, K. Scrivener, J. Weiss
Paper category : conference
Book title: International RILEM Conference on Use of Superabsorbent Polymers and Other New Additives in Concrete
Editor(s): O.M. Jensen, M.T. Hasholt and S. Laustsen
Print-ISBN: 978-2-35158-104-9
e-ISBN: 978-2-35158-105-6
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 223 - 232
Total Pages: 10
Nb references: 27
Language: English

Abstract: Since their introduction three decades ago, shrinkage reducing admixtures (SRAs) have been extensively utilized to reduce the risk of shrinkage cracking in concrete structures. While the majority of research on SRAs has focused on their ability to reduce drying shrinkage, recent studies indicate SRAs also mitigate plastic and autogenous volume changes in cementitious systems. These benefits which are related to altered salt dissolution, pore solution surfacetension depression and viscosity enhancement, enable SRAs to considerably improve the volumetric stability of plastic and hardened concretes. This paper provides an overview of the mechanism of SRAs to reduce shrinkage and cracking by: (1) under plastic conditions: decreasing the magnitude of tensile stresses developed and (2) under autogenous conditions: amplifying crystallization stresses and limiting the effects of self-desiccation at early-ages.

Online publication: 2010-10-04
Publication type : full_text
Public price (Euros): 0.00