Assessment of reinforcement corrosion in fully carbonated concrete through half-cell potential technique: Investigation of the influence of concrete surface wetting

Date of Publication

2-2011

Document Type

Master's Thesis

Degree Name

Master of Science in Civil Engineering

Subject Categories

Civil Engineering

College

Gokongwei College of Engineering

Department/Unit

Civil Engineering

Thesis Adviser

Ronaldo S. Gallardo

Defense Panel Chair

Jason Maximino C. Ongpeng

Defense Panel Member

Mary Ann Q. Adajar
Bernardo A. Lejano

Abstract/Summary

Corrosion of reinforcement is one of the major causes of pre-mature deterioration of reinforced concrete structures. In a tropical country like the Philippines, the cyclic wetting and drying climatic condition favors corrosion induced by carbonation. The half-cell potential (HCP) technique is universally used in locating corroding rebars and in assessing the corrosion risk of concrete structures due to its simplicity, cost-effectiveness and rapid diagnosis of corrosion. This study reports the results of half-cell potential measurements obtained on the 31st service life of reinforced concrete columns which are fully carbonated and contaminated with chloride ions. Corrosion predictions from HCP data obtained at four different levels of wetness of concrete surface: (1) dry; (2) minimally wet; (3) thoroughly wet; and (4) after 2 hours drying of thoroughly wet concrete, were compared with the actual corrosion revealed from the direct visual inspection of reinforcements. Results showed that HCP measurement is most effective when performed on minimally wetted concrete surface. At minimally wetted concrete surface condition, 5 out of 9 severely corroded rebars were detected and two of the most corroded columns have been identified through the potential difference technique and statistical evaluation of HCP data, respectively. The HCP technique has been fairly reliable in detecting the most corroded column. But a more reliable corrosion prediction can be attained if HCP technique is complemented with carbonation depth measurements. Another interesting finding of this study is that other than the highest gradient, the lowest gradient in the potential field can also indicate the location of corroding areas on fully carbonated concrete structure.

Abstract Format

html

Language

English

Format

Electronic

Electronic File Format

MS WORD

Accession Number

CDTG004890

Shelf Location

Archives, The Learning Commons, 12F Henry Sy, Sr. Hall

Physical Description

1 computer optical disc ; 4 3/4 in.

Keywords

Reinforced concrete—Corrosion; Corrosion and anti-corrosives

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3-4-2024

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