Moisture profiles and diffusion coefficients in mortars containing shrinkage reducing admixtures

Title: Moisture profiles and diffusion coefficients in mortars containing shrinkage reducing admixtures
Author(s): M. Pour-Ghaz, R. Spragg, 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: 197 - 206
Total Pages: 10
Nb references: 38
Language: English

Abstract: Shrinkage reducing admixtures (SRAs) have been used over the last three decades to reduce the volume change (i.e., shrinkage) that occurs in cement paste, mortar, and concrete during drying. The goal of reducing shrinkage is to reduce the risk of shrinkage cracking in concrete elements. SRAs alter the properties of the pore solution, such as surface tension and viscosity, which result in a reduction in the magnitude of drying shrinkage, especially at humidities below 80-85%. In addition to altering the magnitude of shrinkage, SRAs appear to alter the rate of drying and diffusivity coefficient. This paper examines the role of SRAs in two ways. First, desorption spectra are measured to obtain the moisture diffusivity of plain mortar and mortar containing SRA. Second, the paper measures relative humidity in slabs to obtain moisture profiles. The relative humidity profile predicted from the non-linear diffusion coefficient is compared with the measured humidity profile.

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