scholarly journals PERBANDINGAN LAJU KOROSI PADA TULANGAN BETON BUSA NORMAL DAN BETON BUSA POZZOLAN

2018 ◽  
Vol 1 (4) ◽  
pp. 885-894
Author(s):  
Zubaidi Amri ◽  
Abdullah Abdullah ◽  
Syarizal Fonna
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Linear Polarization ◽  
Polarization Resistance ◽  
Water Immersion ◽  
Half Cell ◽  
Cell Potential ◽  
Linear Polarization Resistance ◽  
Foamed Concrete ◽  
Potential Mapping

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.

scholarly journals Alternative methodology for linear polarization resistance assessment of reinforced concrete structure

2018 ◽  
Vol 199 ◽  
pp. 06009 ◽  
Author(s):  
Gabriel Samson ◽  
Fabrice Deby ◽  
Jean-Luc Garciaz ◽  
Jean-Louis Perrin
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Current Density ◽  
Linear Polarization ◽  
Concrete Structure ◽  
Polarization Resistance ◽  
Concrete Cover ◽  
Reinforced Concrete Structure ◽  
Linear Polarization Resistance ◽  
Steel Rebar

For reinforced concrete structures, several corrosion detection methods exist: concrete resistivity, half-cell potential or linear polarization resistance (LPR) measurement. The LPR value can be linked to the corrosion rate thanks the Stern-Geary equation if strong hypotheses are made. Existing commercial devices use a guard ring to canalize the current on specific steel rebar area and assume that the steel rebar is uniformly polarized. However, recent works reveal that the top part of the steel rebar, right under the counter electrode, is the most polarized point. The particular point is referred as the point of interest (PI). This works belongs to the DIAMOND project which aims to produce a new corrosion rate measurement device. Comsol® software was used to model the influence of concrete cover, resistivity and injected current on the current density at the PI. Moreover, a significant influence of the steel rebars diameter was also demonstrated. Two types of abacus are built. The first one links to polarization measured on the surface to the polarization on the rebar at the PI. The second links the ratio between the current density at the PI and the density of injected current to concrete cover and steel rebar diameter. The Stern-Geary equation can now be used at the PI without using the approximation of a uniformly polarized rebar. The corrosion state of reinforced concrete structure can be controlled more precisely. The methodology is then applied on two concrete slabs in which three metal bars are embedded at different concrete covers. The first slab is prepared with ordinary concrete while the second contain chloride to artificially activate the corrosion process. The results reveal that the rebars embedded on the first slab are not corroding (icorr ≤0.2 μΑ/cm2) while the second rebar are corroding (icorr>0.2 μΑ/cm2).

Effect of Interrupting Electricity Period on Electrochemical Chloride Extraction of Reinforced Concrete

2015 ◽  
Vol 754-755 ◽  
pp. 342-347
Author(s):  
Mien Van Tran ◽  
Dong Viet Phuong Tran ◽  
Mohd Mustafa Al Bakri Abdullah
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Current Density ◽  
Concrete Structure ◽  
Chloride Concentration ◽  
Steel Reinforcement ◽  
Reinforced Concrete Structure ◽  
Half Cell ◽  
Cell Potential ◽  
Electrochemical Chloride Extraction

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.

scholarly journals Monitoring DIAMOND device for corrosion state evaluation of reinforced concrete structures

2018 ◽  
Vol 199 ◽  
pp. 04007 ◽  
Author(s):  
Gabriel Samson ◽  
Fabrice Deby ◽  
Jean-Luc Garciaz ◽  
Jean-Louis Perrin
Keyword(s):  
Reinforced Concrete ◽  
Linear Polarization ◽  
Concrete Structure ◽  
Polarization Resistance ◽  
Reinforced Concrete Structure ◽  
Linear Polarization Resistance ◽  
Corrosion Evaluation ◽  
Ohmic Drop ◽  
Concrete Resistivity ◽  
Corrosion State

The corrosion of steel rebars is a major issue with respect to the durability of reinforced concrete structure. Several corrosion evaluation methods exist: half-cell potential, concrete resistivity or linear polarization resistance (LPR) measurement. However, these techniques are employed at a given moment and are not suitable for continuous corrosion evaluation. This works belongs to the DIAMOND project which aims to produce a new corrosion state measurement monitoring device. The monitoring probe consists on a cylindrical probe. A ring shape counter-electrode CE is plated on the probe side. At the centre of the CE, a reference electrode (RE) is placed for potential measurement. The device is embedded in concrete at 25 mm of the inspected rebar. The instantaneous ohmic drop observed at the beginning of the polarization measurement is only linked with the concrete resistance which depends on concrete cover and resistivity. A numerical model was developed on Comsol® to create abacuses graph that link concrete resistivity and concrete resistance. Thus, the ohmic drop measure at the beginning of the polarization can now be used to determine regularly concrete average resistivity between the monitoring probe and steel rebar. Two other series of abacus graphs are then introduced in order to determine the polarization resistance of the rebar in front of the monitoring probe (the point of interest (PI)). Two monitoring probes were placed in two types of concrete (one sound concrete and one concrete with chloride). Corrosion potential, concrete resistivity and rebar corrosion rate were monitored over around 200 days. The experimental results obtained with the monitoring probe are finally compared to the results obtained with the surface DIAMOND probe (introduced in the ICCRRR 2018 paper “Alternative methodology for linear polarization resistance assessment of reinforced concrete structure [1]”).

scholarly journals Evaluación mecánica de concreto y de corrosión en mortero con partículas de neumático reciclado

2013 ◽  
Vol 3 (3) ◽  
pp. 188-199
Author(s):  
C. Flores ◽  
S. Rodríguez ◽  
A. Cárdenas ◽  
O. Guarneros
Keyword(s):  
Mechanical Properties ◽  
Corrosion Rate ◽  
Compression Strength ◽  
Linear Polarization ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Hardened Concrete ◽  
Scrap Tire ◽  
Linear Polarization Resistance ◽  
Polarization Resistance Method

RESUMENSe estudió la factibilidad del uso de partículas de neumático reciclado en concreto y morteros. Para evaluar las propiedades mecánicas del concreto endurecido se realizaron pruebas de densidad, resistencia a la compresión y determinación del módulo de elasticidad. Además se determinó la trabajabilidad del concreto en estado fresco mediante la prueba de revenimiento Las muestras se fabricaron con la sustitución de un 5%, 7.5% y 10 % del volumen de la arena por partículas de neumático reciclado. Se determinó mediante la técnica de potencial de corrosión el estado que guardaba en acero revisando de esta manera la probabilidad de corrosión. Para el estudio de la velocidad de corrosión se utilizó la técnica electroquímica de resistencia a la polarización lineal (RPL) en morteros fabricados bajo las mismas condiciones y proporciones que en los concretos. Los resultados mostraron que una mezcla con 7.5% de partículas de neumático reciclado puede ser utilizada en estructuras de resistencia moderada, ligera y ubicadas en ambientes con cloruros.Palabras clave: Concreto; mortero; neumático reciclado; velocidad de corrosión; Propiedades mecánicas.ABSTRACTThe feasibility of using scrap tire particles in the elaboration of concrete and mortar was investigated. To assess the mechanical properties of hardened concrete, tests evaluating of its density, modulus elasticity and compression strength were undertaken. To determine the workability of freshly made concrete, a slump test was also performed. Tests in which 5, 7.5 and 10% of sand were substituted by recycled tire particles were made. The likelihood of corrosion on the steel is determined, using the technique of corrosion potential. To test the velocity of corrosion was used the linear polarization resistance method (LPR method) was utilized under the same conditions as well as fabrication of concrete. It was observed that using 7.5% of recycled tire particles offers satisfactory results in structures of moderate strength and lighter weight located in environments with chlorides.Keywords: Concrete; mortar; recycled tire; corrosion rate; mechanical properties.

Half-cell potential measurements—Potential mapping on reinforced concrete structures

2003 ◽  
Vol 36 (7) ◽  
pp. 461-471 ◽  
Author(s):  
B. Elsener ◽  
C. Andrade ◽  
J. Gulikers ◽  
R. Polder ◽  
M. Raupach
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Half Cell ◽  
Cell Potential ◽  
Potential Mapping

scholarly journals Test of inhibitors for preventing corrosion of steel reinforcement in concrete

2021 ◽  
Vol 32 (2) ◽  
pp. 110-113
Author(s):  
Albana Jano ◽  
Alketa Lame ◽  
Efrosini Kokalari
Keyword(s):  
Corrosion Rate ◽  
Polarization Resistance ◽  
Guar Gum ◽  
Cement Mortar ◽  
Extrapolation Methods ◽  
Half Cell ◽  
Cell Potential ◽  
Reinforced Cement ◽  
Locust Bean ◽  
Corrosion Of Steel

Abstract Concrete is more widely used than any other manmade material. The objective of this paper is to investigate the behavior of reinforced cement when migration corrosion and guar gum inhibitors are used. The concrete samples were exposed in aggressive media H2SO4 1 M and in the presence of 1∙10-3 M Cl-. Electrochemical measurements such as half-cell potential, polarization resistance and Tafel extrapolation methods were performed in order to obtain information on the corrosion behavior of the reinforcing steel in cement mortar. Results demonstrate high resistance polarization and low corrosion rate for concrete sample with inhibitor. The corrosion rate decreases approximately 95% in presence of locust bean gum and 80% in presence of migration inhibitor.

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