Calculation of shrinkage strain in early-age concrete structures - An example with concrete pavements

Author(s): Jun Zhang, Dongwei Hou, Yuan Gao
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: 918 - 929
Total Pages: 11
Language: English

Abstract: 
This paper focuses on the modeling of the distribution of shrinkage strain in early-age concrete pavements. In the modeling, an integrative model for autogenous and drying shrinkage predictions of concrete at early-age is introduced first. Second, a model taking both cement hydration and moisture diffusion into account synchronously is used to calculate the distribution of interior humidity in concrete. The above two models are experimentally verified independently by a series of shrinkage and interior humidity tests on three types of concretes with different compressive strength. Using the models, the distribution of shrinkage strain in early-age concrete pavements under the condition that the pavement surface suffers to drying is calculated. The model results show that the development of interior humidity inside of pavement since concrete cast obeys two stage mode, that is a vapor saturated stage with 100% relative humidity (stage I) and a stage with the relative humidity gradually decreasing (stage II). Within the stage I, a uniform shrinkage strain is expected throughout the slab. By contrast, the shrinkage gradient along the slab depth is obvious in the stage II. The maximum and minimum shrinkage occurs at slab top and bottom respectively. The distribution of shrinkage strain along the pavement depth is nonlinear and the nonlinearity is strong close to the drying face and the rest is weak. Concrete strength can significantly influence the magnitude of shrinkage strain within the slab.

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