Modelling carbonation rates in concretes with similar strength and with and without slag

Author(s): Sundar Rathnarajan1, Naga Pavan Vaddey2, Radhakrishna G. Pillai1, Ravindra Gettu1,and Manu Santhanam1
Paper category: Proceedings
Book title: Proceedings of the 71st RILEM Annual Week & ICACMS 2017,Chennai,India, 3rd -8th September 2017
Editor(s): Manu Santhanam
Ravindra Gettu
Radhakrishna G. Pillai
Sunitha K. Nayar
ISBN: 978-2-35158-196-4
ISBN: 978-2-35158-190-2 (Set)
e-ISBN: 978-2-35158-191-9:
Publisher: Published by RILEM Publications S.A.R.L.
Publication year: 2017
Pages: 278-285
Total Pages: 8
Language : English

Abstract: The service life of reinforced concrete elements subjected to carbonation could be lesser than
the design life due to premature corrosion initiation. The rate of carbonation in concrete
systems with SCM is reported to be higher than that in concrete made of OPC at a similar
mixture proportion. This article presents the service life estimation for cases with four
concrete mixes of same compressive strength grade. These were cast with and without slag.
The concrete mixes with (i) two w/b ratios (0.50 and 0.55); (ii) three binder contents (310,
340 and 370 kg/m3) were also considered. The concrete prism specimens were cast and
subjected to moist curing. Then, all the specimens were exposed to the natural unsheltered
environment in Chennai, India for 3 years and the depth of carbonation was measured using
phenolphthalein indicator. After 2 years of exposure, the concrete with slag exhibited lower
rate of change of carbonation rate than the concrete without slag. Based on the natural
carbonation coefficient, KNC, values obtained using the experimental data and Tutti’s
square-root model, the service life of a typical concrete bridge girder was estimated.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00