PREDICTING DEPTH OF CARBONATION OF CONCRETE - A PERFORMANCE-BASED APPROACH

Author(s): Rakesh Gopinath, Mark Alexander and Hans Beushausen
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 439-446
Total Pages: 8
Language: English

Abstract: The deterioration of concrete structures by environmental actions has become a great concern for engineering design and maintenance. In most cases, corrosion of the reinforcing steel in the concrete is the main cause of deterioration affecting the durability performance of the structures. The alkaline environment of the concrete protects the reinforcing steel by maintaining it in a passive state. However, the protection is compromised by carbonation of concrete which may be followed by corrosion in the presence of sufficient oxygen and moisture. Hence there is a need to understand the mechanism of carbonation and adequately model it to be useful in service life design. The main aim of the study reported here is to develop or modify an existing carbonation model for natural exposure conditions, with the South African Oxygen permeability Index (OPI) test parameter as the key variable. For the experimental work, twelve different concrete mixes were produced by varying the water:binder ratio (w/b), curing conditions, and by using fly ash. The specimens were exposed to four different sites for natural carbonation, with the depth of carbonation measured periodically. The carbonation model developed is validated based on the experimental results and the limitations are pointed out.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00