Better Understanding of Tide’s Influence on Half-cell Potential Measurements for Reinforced Concrete in Marine Environment

Author(s):  
Lucas Bourreau ◽  
Véronique Bouteiller ◽  
Franck Schoefs ◽  
Laurent Gaillet ◽  
Benoît Thauvin ◽  
...  
Author(s):  
Shrabanee Giri

Corrosion of reinforcement in concrete affects the strength and durability of reinforced concrete structure. Monitoring and maintenance of concrete structure throughout the service life prevent the ingress of corrosion at the initial stage. Half-cell potential meter was developed and fabricated to monitor the corrosion potential of reinforcement in a M25 grade concrete. Half-cell potential test and accelerated corrosion test has been carried out in marine environment of 3.5% of NaCl solution. The potential behaviour of specimen subjected to accelerated corrosion is studied throughout the test period. The results were obtained in terms of current flow behaviour and weight loss. Obtained results has been analyzed graphically and a comparative analysis has been carried out to know the rate of corrosion occurred in the specimen by accelerated corrosion test and half-cell potential test. Obtained results clearly indicates that the potential behaviour value increases with increase in time from 160 mV on day 1 to 949 mV on day 5. In the other way the compressive strength value for corroded specimen is lesser than the controlled specimen subjected to accelerated corrosion.


2004 ◽  
Vol 18 (3) ◽  
pp. 155-162 ◽  
Author(s):  
Veerachai Leelalerkiet ◽  
Je-Woon Kyung ◽  
Masayasu Ohtsu ◽  
Masaru Yokota

2015 ◽  
Vol 754-755 ◽  
pp. 342-347
Author(s):  
Mien Van Tran ◽  
Dong Viet Phuong Tran ◽  
Mohd Mustafa Al Bakri Abdullah

Electrochemical chloride extraction – ECE is an effective method to rehabilitate reinforced concrete structure, which has been corroded. This study investigated concentration of chloride remained in concrete and half-cell potential of the steel reinforcement after ECE using interrupting period of electricity current. Efficiency of ECE using Ca (OH)2was surveyed with two current density of 0.5 and 1A/m2. In this study, ECE treatment was proceeded intermittently in approximately 8 weeks. Results pointed out that chloride concentration decreased to 30 – 60% significantly, especially at in the vicinity of reinforcing steel. Simultaneously, half-cell potential of the steel reinforcement after 4 weeks halted treatment stabilizes in low-corrosion rate.


2003 ◽  
Vol 36 (7) ◽  
pp. 461-471 ◽  
Author(s):  
B. Elsener ◽  
C. Andrade ◽  
J. Gulikers ◽  
R. Polder ◽  
M. Raupach

2018 ◽  
Vol 1 (4) ◽  
pp. 885-894
Author(s):  
Zubaidi Amri ◽  
Abdullah Abdullah ◽  
Syarizal Fonna

Abstract: Reinforced concrete foam is one alternative to replace conventional reinforced concrete on structural elements. This study aims to measure the The media immersion and variation of specific gravity (SG) is a variable of interest in this study. The specimen type used is Normal foamed concrete (BB) and pozzolan foamed concrete (BBP). The test specimens used were 8 x 8 x 50 cm, with single reinforcement Ø10 mm in it. Reinforced placement of the reinforcement so that the test specimen has a thickness of 4 cm concrete cover. The specimen was immersed in freshwater and artificial seawater in the form of a 3.5% sodium chloride solution. The measurements results using half-cell potential mapping (HCPM) technique described the highest corrosion risk location. At this location corrosion rate measurement performed using linear polarization resistance (LPR) method. The corrosion rate calculation result of normal foamed concrete SG 1,2, 1,4, 1,6 with NaCl 3.5% and  fresh water immersion medium ranged from 0,621 mpy up to 0,854 mpy and 0,194 mpy up to 0,304 mpy. The corrosion rate value of pozzolan foamed concrete SG 1,2, 1,4,1,6 with 3.5% NaCl and  fresh water immersion media ranges from 0,429 mpy up to 0,545 mpy and 0,072 mpy up to 0,120 mpy. The larger SG value of the foamed concrete specimen used, the less corrosion rate occurs. Corrosion behavior of pozzolan foamed concrete is better than normal foam concrete, this phenomenon occurs due to the effect of adding 10% pozzolan which causes better foamed concrete permeability, so that the resistance of concrete against corrosion increased. In general the corrosion rate of pozzolan foamed concrete in the freshwater environment and corrosive environment (artificial seawaters of NaCl 3.5%) is smaller than the corrosion rate of normal foamed concrete. Abstrak: Beton busa bertulang merupakan salah satu alternatif untuk menggantikan beton bertulang konvensional pada elemen struktural. Penelitian ini bertujuan untuk mengukur laju korosi pada beton busa bertulang. Media rendaman dan variasi berat jenis (SG) merupakan variabel yang ditinjau dalam penelitian ini. Jenis benda uji yang digunakan berupa beton busa normal (BB) dan beton busa pozzolan (BBP). Benda uji yang digunakan berbentuk balok 8 x 8 x 50 cm, dengan tulangan tunggal Ø10 mm didalamnya. Dilakukan penempatan tulangan sehingga benda uji memiliki ketebalan selimut 4 cm. Benda uji direndam menggunakan air tawar dan air laut buatan berupa larutan Natrium Clorida 3,5%. Hasil pengukuran menggunakan teknik half-cell potential mapping (HCPM) menggambarkan lokasi yang memiliki resiko tertinggi terkorosi. Pada lokasi ini dilakukan pengukuran laju korosi dengan menggunakan metode linear polarization resistance (LPR). Hasil perhitungan laju korosi pada beton busa normal SG 1,2 sampai 1,6 dengan media rendaman larutan NaCl 3,5% dan air tawar berkisar antara 0,621 mpy sampai dengan 0,854 mpy dan  0,194 mpy sampai dengan 0,304 mpy. Nilai laju korosi pada beton busa pozzolan SG 1,2, 1,4, 1,6 dengan media rendaman NaCl 3,5% dan air tawar berkisar antara 0,429 mpy sampai dengan 0,545 mpy dan 0,072 mpy sampai dengan 0,120 mpy. Semakin besar nilai SG benda uji beton busa yang digunakan, maka laju korosi yang terjadi semakin kecil. Perilaku korosi beton busa pozzolan lebih baik dari pada beton busa normal, fenomena ini terjadi akibat pengaruh penambahan 10% pozzolan yang menyebabkan permeabilitas beton busa semakin baik sehingga ketahan beton terhadap korosipun semakin meningkat. Secara umum laju korosi pada beton busa pozzolan dilingkungan air tawar dan lingkungan korosif (air laut buatan NaCl 3,5%) lebih kecil dibandingkan laju korosi beton busa normal.


2016 ◽  
Vol 63 (2) ◽  
pp. 128-136 ◽  
Author(s):  
Zhiming Ma ◽  
Tiejun Zhao ◽  
Jianzhuang Xiao ◽  
Ting Guan

Purpose – Rebar corrosion in reinforced concrete is the major reason for the durability degradation, especially under harsh environment. This paper presents an experiment conducted to investigate the influence of freeze-thaw cycles on the rebar corrosion in reinforced concrete. The purpose of this paper is to provide fundamental information about rebar corrosion under frost environment and improvement measures. Design/methodology/approach – The related elastic modulus and compressive strength of different concrete specimens were measured after different freeze-thaw cycles. The accelerated rebar corrosion test was carried out after different freeze-thaw cycles; additionally, the value of calomel half-cell potential was determined. The actual rebar corrosion appearance was checked to prove the accuracy of the results of calomel half-cell potential. Findings – The results show that frost damage aggravates the rebar corrosion rate and degree under freeze-thaw environment; furthermore, the results become more obvious with the freeze-thaw cycles increasing. Mixing the air-entrained agent into fresh concrete to prepare air-entrained concrete, increasing the cover thickness and processing the surface of concrete with a waterproofing agent can significantly improve the resistance to rebar corrosion. From the actual appearance of rebar corrosion, the results of calomel half-cell potential can well reflect the actual rebar corrosion in reinforced concrete. Originality/value – The durability of reinforced concrete is mainly determined on chloride penetration that brings about rebar corrosion in chloride environments. Furthermore, the degradation of concrete durability becomes more serious in the harsh environment. As the concrete exposure to the freeze-thaw cycles environment, the freeze-thaw cycles accelerate the concrete damage, and the penetration of chloride into the concrete becomes easier because of the growing pore and crack sizes. In addition, rebar corrosion caused by chloride is one of the major forms of environmental attack on reinforced concrete. The tests conducted in this paper will describe the rebar corrosion in reinforced concrete under freeze-thaw environment.


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