WATER PENETRATION INTO FROST DAMAGED CONCRETE

Author: Peng Zhang, Yuan Cong, Wanyu Zhao, Wenchao Geng, Zhengzheng Dai, Tiejun Zhao
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference Segment on Frost Action in Concrete
Editor(s): Marianne Tange Hasholt, Katja Fridh and R. Doug Hooton
ISBN:978-2-35158-182-7
e-ISBN:978-2-35158-183-4
Publisher:RILEM Publications SARL
Publication year:2016
Pages:242-251
Total Pages:10
Language:English

Abstract: In service life, concrete can be damaged either by mechanical or environmental loads or by combined ones. These damages will strongly influence water movement in concrete which could later lead to more serious deteriorations. This paper used neutron radiography to investigate the influence of frost damage on water penetration into concrete. In addition, the improvement of frost resistance by addition of air entrainment was investigated. The results indicate that it is possible to visualize penetration of water into the porous structure of concrete by neutron radiography. Further evaluation of the test data allows determining time-dependent moisture profiles quantitatively with high resolution. After concrete is damaged by freeze-thaw cycles water penetration into ordinary concrete is accelerated. It can be shown that frost damage is not equally distributed in specimens exposed to freeze-thaw cycles.Thermal gradients lead to more serious damage near the surface. The beneficial effect of air entrainment on frost resistance has been demonstrated. After 50 freeze-thaw cycles, air entrained concrete showed no measurable increase in water absorption. But layers near the surface of concrete absorbed slightly more water after 200 freeze-thaw cycles although the dynamic elastic modulus remained constant. Results presented in this paper help us to better understand mechanisms of frost damage of concrete.

Online publication:2016
Publication type:full_text
Public price (Euros):0.00