Field survey on re-bar corrosion of carbonated existing concrete buildings in Japan

Author(s): Kei-ichi Imamoto, Manabu Kanematsu, Chizuru Kiyohara, Hitoshi Hamasaki, Toru Kinose, Kouji Teranishi, Takafumi Noguchi
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials Systems and Structures (SMSS2019) Durability, Monitoring and Repair of Structures
Editor(s): Ana Baričević, Marija Jelčić Rukavina, Domagoj Damjanović, Maurizio Guadagnini
ISBN: 978-2-35158-217-6
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 2-9
Total Pages: 813
Language : English

Abstract: This paper reports re-bar corrosion of existing concrete buildings based on field survey. Twenty-one buildings ranging in age from 42 to 100 years were surveyed in 2017. The survey results indicated that the re-bar was corroded only in cases of poor cover thickness. Re-bar corrosion of concrete at low relative humidity was quite minor although carbonation had significantly progressed. This might indicate that not only carbonation but also moisture is key to cause re-bar corrosion. It was found that a relative humidity of approximately 80% and re- bar with thin cover thickness strongly affect the corrosion in a carbonated concrete structure. At an appropriate cover thickness layer, the relative humidity of the concrete was stable. On the other hand, concrete carbonation progress was not significant due to a high moisture content under relative humidity of 80% or more, which prevented CO2 ingress from the outer zone. The truth of carbonation induces re-bar corrosion, given a sufficient cover thickness under relative humidity of 80% or more, should be discussed in the future.

Online publication :2019
Publication type : full_text
Public price (Euros) : 00