Modelling of Microstructure Development and Disintegration of Cementitious Composite under Repeated Pore Water Pressure in Micro- Spaces

Author(s): Koichi Maekawa and Yuya Takahashi
Paper category: Proceedings
Book title: 3rd International RILEM Conference on Microstructure Related Durability of Cementitious Composites
Editor(s): Changwen Miao, Wei Sun, Jiaping Liu, Huisu Chen, Guang Ye and Klaas van Breugel
Print-ISBN: 978-2-35158-188-9
e-ISBN: 978-2-35158-189-6
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 17-24
Total Pages : 8
Language : English

Abstract: Reinforced concrete decks submerged in water suffer from considerable deterioration owing to high cycle repetition of traffic loads with increasing rise of inter-crack water pressure, which leads to serious damages to the top surface of concrete decks due to dropping (disintegration) of cement binder. In this study, an attempt was made to incorporate the disintegration of concrete composites into a three-dimensional multi-scale finite element analytial platform, which is capable of simulating the micro-pore structure developments and tracing the path from the occurrence of cracking to the structural out-of-plane shear failure via crack propagation. In the platform, to assess the effect of disintegration as well as the damage by ASR-expansion, poro-mechanical approach is applied and the degree of damage with disintegration is expressed by the pore water pressure histories.
The analytical platform is applied to the fatigue life assessment of RC bridge decks. First, fatigue lives of bridge decks in submerged conditions are investigated with the simulations and the results showed that the fatigue lives can be shorter in 1-2 order in the wet environment than on an ordinary reinforced concrete deck, which has the agreement with the previous studies. Then targeting the bridge decks suffered by the ASR, previous experimental works for bridge decks is referred for experimental verification. It is confirmed that the models introduced in this study may bring about fair behavioural simulation. Furthermore, both experiments and analyses indicate that ASR does not always cause unfavourable structural performances of RC slabs under repeated traffic loads, but it might have led to some extension of fatigue life. The proposed model also promotes the study on so called disintegration of concrete composites owing to the cyclic pore-pressure provoked by the
fatigue loading and it was suggested that cracks due to ASR-induced expansion is large enough to release the water pressure caused by cyclic loadings, which can leads to less disintegration.

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