Thermal dilation and internal relative humidity in hardened cement paste

Title: Thermal dilation and internal relative humidity in hardened cement paste
Author(s): Zachary C. Grasley, David A. Lange
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: 18
Language: English

Abstract: The coefficient of thermal dilation of hardened cement paste and concrete is a function of the state of internal moisture in the pore system. It has been theorized that changes in the pore fluid pressure induced by temperature change causes additional dilation when the material is partially saturated. Drying shrinkage stresses in early-age concrete also evolve from changes in the pore fluid pressure. The Kelvin-Laplace Equation relates changes in the pore fluid pressure to the measured internal relative humidity. This research investigated the relationship between the relative humidity in the micropore structure of hardened cement paste and the changes in pressure initiated by temperature changes. It was found that the measured changes in internal relative humidity and the coefficient of thermal dilation support the theory that the coefficient of thermal dilation in hardened cement and concrete is augmented by changes in pore fluid pressure. The additional thermal strain caused by changes in pore fluid pressure was successfully modeled using internal relative humidity measurements as a main parameter.

Online publication: 2004-03-25
Classification: Driving Forces
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143926.021