Half-cell Potential Test Research Articles

IoT for Cathodic Protection System as Iron Concrete’s Corrosion Protection

Iron concrete or reinforcement steel is steel used for reinforcement of concrete construction or known as reinforced concrete. Iron concrete can undergo a corrosion process caused by chemical or electrochemical reactions between reinforcement steel and its environment. One way to protect concrete from corrosion is cathodic protection. There are two types of cathodic protection, namely sacrificial anodes and impressed current cathodic protection (ICCP). ICCP is more commonly used for protection in reinforced concrete structures. In ICCP, negative current flows to the iron concrete and positive current flows to the anode. This is to protect the concrete from corrosion. In addition to the corrosion protection system, there is also a half-cell potential test to measure the chance of corrosion of the concrete. The project used IoT to monitor and control the ICCP. Measurements are made by reading the potential difference between the reference electrode and the iron concrete. The probability of corrosion can be determined by reading the corrosion probability table with ASTM C879-09 standard. The ICCP system in general still uses the manual method so that there are time efficiency problems in controlling the voltage and current for ICCP purposes, cannot schedule the provision of electric current and monitor it at any time, especially if the electric current flowing in the concrete is higher than the standard it should be. Based on the results of the tests carried out, the IoT system can regulate the power supply by setting the voltage and current and can schedule the power supply to provide electric current to the iron concrete and can provide notifications if the electric current flowing in the concrete is more than or less than ICCP standard.

Half-Cell Electric Potential Testing Equipment

The pace of consumption of the building up bars is one of the significant boundaries expected to gauge the lingering administration life of a built up concrete (RCC) span deck. In the current review, first, the straight polarization obstruction procedure was utilized to gauge the erosion paces of plain gentle steel and cold wound twisted (CTD) bar examples, which were regularly utilized in the more established existing extensions. To consider the changeability of a consumption rate, the recurrence conveyances of the erosion rates for the two sorts of not entirely settled. Then, a probabilistic methodology was embraced for evaluating a current RC support and-section street span deck, exposed to consumption of bars inferable from air-borne chlorides. A computational model was created utilizing the Monte Carlo reenactment strategy, to survey the decrease in the flexural limit of a common brace. It was seen that the decrease in the mean limit and the scattering of the limit as for time, were high with the deliberate factual boundaries of the erosion pace of CTD bars. The half cell testing technique utilizes this cycle to identify whether the building up steel is under dynamic consumption. This technique uses a multimeter to quantify the expected contrast between the steel and half cell device. The examination of the expected contrast between the steel and a half cell device. The investigation of the potential distinction can show on the off chance that dynamic erosion is occurring on the building up steel. Keywords: NDT, Coastal environment, Half-cell potential Test, Chloride content, Corrosion.

Effect of fly ash on compressive strength, carbonation and corrosion resistance of reinforced concrete: a systematic review

Purpose The purpose of this paper is to study and analyze the effects of fly ash (FA) as a mineral admixture on compressive strength (CS), carbonation resistance and corrosion resistance of reinforced concrete (RC). In addition, the utilization of inexpensive and abundantly available FA as a cement replacement in concrete has several benefits including reduced OPC usage and elimination of the FA disposal problem. Design/methodology/approach Reinforcement corrosion and carbonation significantly affect the strength and durability of the RC structures. Also, the utilization of FA as green corrosion inhibitors, which are nontoxic and environmentally friendly alternatives. This review discusses the effects of FA on the mechanical characteristics of concrete. Also, this review analyzes the impact of FA as a partial replacement of cement in concrete and its effect on the depth of carbonation in concrete elements and the corrosion rate of embedded steel as well as the chemical composition and microstructure (X-ray diffraction analysis and scanning electron microscopy) of FA concrete were also reviewed. Findings This review provides a clear analysis of the available study, providing a thorough overview of the current state of knowledge on this topic. Regarding concrete CS, the findings indicate that the incorporation of FA often leads to a loss in early-age strength. However, as the curing period increased, the strength of fly ash concrete (FAC) increased with or even surpassed that of conventional concrete. Analysis of the accelerated carbonation test revealed that incorporating FA into the concrete mix led to a shallower carbonation depth and slower diffusion of carbon dioxide (CO2) into the concrete. Furthermore, the half-cell potential test shows that the inclusion of FA increases the durability of RC by slowing the rate of steel-reinforcement corrosion. Originality/value This systematic review analyzes a wide range of existing studies on the topic, providing a comprehensive overview of the research conducted so far. This review intends to critically assess the enhancements in mechanical and durability attributes (such as CS, carbonation and corrosion resistance) of FAC and FA-RC. This systematic review has practical implications for the construction and engineering industries. This can support engineers and designers in making informed decisions regarding the use of FA in concrete mixtures, considering both its benefits and potential drawbacks.

Učinkovitost armature premazane ekstraktom kore nara u betonu pri zaštiti od korozije

This paper aimed to develop an affordable, eco-friendly, and accessible natural inhibitor derived from the peel of the pomegranate fruit. An extract was prepared from the pomegranate peel and utilised as a corrosion-resistant coating known as pomegranate peel extract (PPE) applied to the steel rebar. The corrosion resistance of the PPE-coated steel was evaluated using accelerated carbonation, impressed voltage, half-cell potential, weight loss, and accelerated corrosion tests. The carbonation test revealed that the uncoated steel rebar displayed patches, indicating carbonation, whereas the PPE-coated rebar was not affected, demonstrating an uncarbonated zone. Moreover, the half-cell potential test clearly indicated that the PPE-coated steel rod exhibited a moderate risk of corrosion with a potential of -247 mV. Particularly, the weight loss of the uncoated conventional steel was 40 % greater than that experienced by the PPE-coated rod. In the accelerated corrosion test, the PPE-coated rods took longer to develop initial cracks in the concrete, with durations of 182, 206, and 230 h for samples 1, 2, and 3, respectively, which were comparatively higher than those of conventional concrete. Thus, the test results of the PPE-coated steel were compared with those of the uncoated conventional steel, and the performance of the PPE-coated rod in terms of corrosion resistance was evaluated.

Mechanical properties and corrosion resistance of recycled aggregate concrete exposed to accelerated and natural marine environment

This paper presents the effect of long-term exposure (simulated and natural) on the mechanical and durability characteristics of ordinary Portland cement concrete (OPCC) with and without recycled concrete aggregate (RCA) prepared using two water-cement (w/c) ratios. Each of the four concrete mixes (i.e. 0.40-R0, 0.40-R30, 0.43-R0 and 0.43-R30) was exposed to the simulated ((i.e. Fog apparatus/chamber as per provisions of ASTM B117) and two natural marine environments (on a water jetty and submerged in the seawater) for a period of 90, 180 and 365 days. To observe the long-term effect of the simulated and natural environment exposure, the exposed specimens were tested for compressive strength, splitting tensile strength, pull-out strength, and half-cell potential test as per the standard testing provisions of ASTM C39, ASTMC496, ASTMC900, and ASTMC876, respectively. The comparison of the results showed that the concrete specimens exposed to the natural marine environment submerged in the seawater resulted in reduced compressive and pull-out strengths, high and increased split tensile strength, and poor resistivity to corrosion as compared to the one placed on a deck of water jetty and simulated marine environment. The concrete prepared by using 30% RCA was significantly affected by the exposures as compared to the natural environment and a difference of nearly 30% in results of compressive strength, split tensile strength, and pull-out strength and a difference of 40% was found in resistivity to corrosion. Similarly, the high w/c ratio also affected the compressive strength, split tensile strength, pull-out strength, and resistivity to corrosion of concrete. The results of microstructure also confirmed that the concrete exposed to a harsh environment underwent severe deterioration, which led to the lessening of the mechanical properties.

Confinement effectiveness of 2900psi concrete using the extract of Euphorbia tortilis cactus as a natural additive

Concrete with cactus is a new type of concrete with high fluidity, strength, and durability with more remarkable advantages. The present paper discusses the role of Euphorbia tortilis cactus (ETC) to achieve the strength, durability, and corrosion resistance properties of concrete specimens. In this work, M20 (2900psi) concrete was designed as per Indian standards, and cactus were used as an additive. ETC extracts from Tamilnadu (India) were replaced with water (1%, 3%, 5%, 7%, 9%) by weight. The performance of cactus concrete was analyzed through destructive and non-destructive tests to investigate strength properties. In addition to that, specific tests such as sorptivity, permeability, half-cell potential test, etc. have been performed further for durability and corrosion resistance. ETC concrete improves the fluidity, thereby enhancing the workability of the mixture. Concrete was analyzed through Scanning Electron Microscopy (SEM) to identify the particle distribution. Experimental investigation shows that the strength properties of concrete have been enhanced by 29% due to Polysaccharides at optimum level. However, durability is achieved at a high, which stimulates the effective filling of voids in concrete. It shows that better performance of concrete gives at optimum dosage. On Euphorbia tortilis cactus concrete, no literature has been discovered.

Corrosion potential of coated steel bar embedded in sea-water mixed mortar

Corrosion of embedded steel bars in concrete structures is the most impactful deterioration case in the world therefore many researchers and engineers are looking for the unknown mechanism related to the occurrence process, the effect of the damaged structures to its capacity and serviceability, and the intervention methods to control the rate of corrosion nowadays. One of the most prevalent liquid materials used in concrete is freshwater. However, the lack of freshwater for basic requirements in certain regions necessitates the adoption of an alternate material. Seawater, abundant in Indonesia, has the ability to substitute freshwater in concrete mixtures. However, its high concentration of chloride ions might raise the risk of corrosion in reinforced concrete structures. The laboratory experiment was proposed to find the empirical test result of the performance of corrosion prevention to the seawater mix RC structures. Three type of cements (PPC, PCC, and PPC-PCC mixture) were used as binder and two type of protection (steel coating and no coating) were applied in this research. One day after specimen casting, it were demolded and cured under water condition until 28 days. After that, the cylindrical and beams specimens were tested and the cubical specimens were exposed to three conditions (air-dry, wet, and dry-wet cycle) until a half-year and the half-cell potential test was conducted periodically every week. Based on the results, it demonstrated that the steel coating is the most suitable corrosion prevention method and PCC is recommended to maintain the corrosion potential stable to be passive.

RETRACTED: The influence of fiber RC beams under flexure on the chloride-induced corrosion

Corrosion of rebars is the main cause of the deterioration of reinforced concrete structures. In an aggressive marine environment, rebar corrosion occurs due to chloride ion penetration of the reinforced concrete (RC). This paper presents the findings of an experimental study conducted to determine the influence of fiber reinforcement on the chloride-induced corrosion and flexural behaviour of reinforced concrete beams. Uncracked and cracked reinforced concrete beams were exposed to a 16.5% chloride solution in a cyclic immersion for three years, causing them to corrode naturally. The half-cell potential test was carried out to monitor the corrosion potentials, and flexural tests were carried out in a three-point bending configuration to assess the structural performance. Gravimetric tests revealed that bars in conventional concrete had higher degrees of corrosion than those in fiber-reinforced concrete with a variation of 11 %. With increasing crack widths (max 0.2–0.3 mm), there was a tendency toward early corrosion initiation, in contrast, fiber addition delayed the process of corrosion initiation by 6 %. Regarding flexural performance, fiber-reinforced beams are significantly better than conventional concrete beams, especially steel fiber incorporated concrete beam's residual flexural strength 16 % more than the conventional concrete beams.

Corrosion evaluation of steel bars in steam-cured concrete under chloride attack and alkali–silica reaction

One of the challenges to reinforced concrete slabs in bridges is deterioration due to rebar corrosion by deicing salts. In order to simulate a concrete slab subjected to deicing salt penetration from the top surface of the bridge slab during winter, high-strength steam-cured concrete with double-layer reinforcements was exposed to 10% sodium chloride solution to investigate rebar corrosion. Five concrete mix proportions were prepared, including high early strength concrete and concrete containing fly ash and blast furnace slag as supplementary cementitious materials (SCMs). For both the high early strength and fly ash concretes, alkali active andesite in the pessimum proportion was mixed with coarse aggregates to investigate the effect of alkali–silica reaction (ASR) on rebar corrosion. It was found that the combined effects of chloride attack and ASR adversely affected the corrosion resistance of high early strength concrete. Fly ash concrete had excellent performance as to corrosion resistance and ASR mitigation. Results also showed that a widely used electrochemical technique known as the half-cell potential test can satisfactorily diagnose corrosion of double-layer reinforced concrete. Concrete specimens containing SCMs with no ASR threat showed no signs of steel bar corrosion and significantly low chloride diffusion coefficients after 3 years.

Durability properties of self compacting concrete partial replacement of fine aggregate with waste crushed glass

This research work presents the durability properties of self-compacting concrete partial substitution of sand with waste crushed glass. In SCC cement was replaced with Fly-ash (15%), Alccofine (20%) by weight of cementitious material. These binder proportions are fixed for all mixes. Waste crushed glass has sufficient amount of amorphous silica content which is easily substituted to fine aggregate in SCC. Proportions are taken to replace the fine aggregate with waste crushed glass was 0%, 10%, 20%, 30% and 40% by weight of sand in mix. Grade of the concrete prepared was M70 and W/C was taken as 0.3. In present research work acid attack test and half-cell potential were carried out. For Acid attack test cube specimens of size (100 mm × 100 mm × 100 mm) were casted and cured for 90 days, for half-cell potential test cylinders (200 mm × 100 mm) were casted and cured for 90 days. In acid attack test 5% of hydrochloric acid and sulfuric acid were taken for testing. The results of normal concrete and concrete with waste crushed glass are compared. Test results showing better performance with waste crushed glass in Sulfuric acid and Hydrochloric acid. With 40% waste crushed glass, specimens immersed in Sulfuric acid, weight loss and strength loss are 3.8% and 4.85% respectively by weight before immersed in Sulfuric acid. With 40% waste crushed glass, specimens immersed in Hydrochloric acid weight loss and strength loss are 2.56% and 6.08% respectively by weight before immersed in Hydrochloric acid. Half-cell potential test values are showing increasing the glass content corrosion of steel was decreasing.

Durablilty propeties of geopolymer concrete partial replacement of fine aggaregate with waste crushed glass

This research work focused on durability aspects of geopolymer concrete partial replacement of fine aggregate with waste crushed glass. The waste crushed glass contains a high amount of amorphous silica. The GPC40 grade geopolymer concrete prepared was fly ash, alccofine with constant percentages (85%+15%), alkaline activators, and waste crushed glass. In this research geopolymer concrete GPC40 fine aggregate replaced by waste crushed glass with different percentages 0%, 10%, 20%, 30% & 40% by weight of sand. The alkaline solutions were taken with 10 M. The samples were cured at ambient temperature for 7, 28 and 90 days. The durability tests were conducted after 90 days of ambient curing. Durability tests conducted were acid attack test and half-cell potential test. Sulfuric acid and Hydrochloric acid were taken 5% concertation. Results were compared with normal GPC and waste crushed glass GPC showing better performance in acid attack tests and half-cell potential test. With 40% replacement of waste crushed glass GPC specimens immersed in sulfuric acid the percentage weight loss and strength loss were 2.03 % and 1.81% respectively. With 40% replacement of waste crushed glass GPC specimens immersed in sulfuric acid the percentage weight loss and strength loss were 3.09% and 1.68 % respectively. Half-cell potential results showing increasing glass content decreasing corrosion of steel.

The Study of Half-cell Potential Behaviour of Reinforced Concrete in Marine Environment

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.

Quantitative determination of corrosion status of rebar by electrochemical parameters

In this paper, the relationship between electrochemical parameters and corrosion status of rebar was analyzed by measuring macro-current and potential difference of self-made anode ladder monitoring system under different environmental conditions.Laboratory tests show that the anode ladder monitoring system can better judge the corrosion status of steel bars and provide a basis for structural durability evaluation and remaining life prediction. Reinforced concrete is the most widely used building material in engineering. The durability of reinforced concrete structure gradually declines under the long-term action of unfavorable factors in using environment. At present, there are many "models" for predicting the durability life of concrete published in the world, and more researches are being carried out. The most studied "model" is the "model" related to corrosion, especially the relationship between reinforcement corrosion and concrete durability, is the most common and in-depth research. The problem of durability of reinforced concrete structures caused by corrosion of reinforcing bar has been paid more and more attention in engineering field. Early detection and diagnosis of reinforcement corrosion is an important prerequisite for durability evaluation, remaining service life prediction and maintenance scheme selection of reinforced concrete structures.The development of accurate and reliable on-site monitoring technology of reinforcement corrosion has become the focus of scholars at home and abroad. In order to monitor the corrosion of reinforcement in concrete, some electrochemical parameters need to be measured by sensors. These electrochemical parameters include: potential distribution, macrocurrent, concrete resistance, and so on. Among them, the measurement of macrocurrent is a relatively simple and easy method, which has been widely used in the measurement of reinforcement corrosion. Using this method, in recent years, many countries have developed anodic sensor systems for monitoring reinforcement corrosion, a typical non-destructive monitoring system for the embedded durability of TRAPEZOIDAL anode ladder concrete structure is developed by the Institute of Civil Engineering, Aachen University of Technology, Germany, the corrosion degree and depth of steel bar in concrete can be measured for a long time by embedding steel bar sensors with different depths in concrete, which has been put into engineering application in many countries. In this paper, a self-made multi-group anode ladder monitoring system is designed in the laboratory. The corrosion status of each anode steel bar and the change of electrochemical parameters are obtained by using the method of half-cell potential test in the environmental solution of different concentrations, the criterion of electrochemical parameters to determine the corrosion status of rebar was obtained.

Alkali-activated concretes based on high unburned carbon content fly ash: carbonation and corrosion performance

This study investigates the carbonation behaviour of alkali-activated fly ash-based (AFA) concretes. AFA contains 20.67% of unburned carbon. GBFS and OPC were used as sources of calcium (20%). A mixture of NaOH and Na2SiO3 was used as activator. OPC concrete was used as reference material. AFA/GBFS, AFA/OPC and OPC concretes, with and without reinforcing steel, were exposed to accelerated carbonation in a chamber under controlled conditions (25 °C, 65% RH, 1% CO2). In the non-reinforced concrete, the carbonation depth and compressive strength were evaluated up to 360 days. FTIR and SEM were used as complementary tests. Given that carbonation is one of the causes of corrosion in reinforcing steel, the electrochemical behaviour of steels embedded in alkali-activated concrete was evaluated using half-cell potential test, polarization curves and linear polarization resistance techniques. According to the obtained results, AFA/GBFS and AFA/OPC concretes are more susceptible to carbonation than OPC with compressive strength losses of up to 40%. Regarding the corrosion behaviour of the reinforcing steel, the AFA/GBFS concrete showed very negative potentials and high corrosion densities; however, at the end of the exposure period (20 months), the reinforcing steel showed no signs of deterioration, unlike the steel embedded in the OPC concrete.

Behaviour of alkali activated concrete under marine conditions

This study aims to investigate the mechanical and durability behavior of flyash and slag based alkali activated concrete mixes under marine conditions. To fulfil the aim of this study, various tests such as Compressive Strength test, Sorptivity test, Half Cell Potential test and Alkalinity tests were done on both flyash and slag based alkali activated concrete. The experimental results showed that the alkali activated concrete attains its strength at earlier stages when compared to control concrete and it also has low sorptivity value which influences much indurability under marine conditions. Though it was cured in acidic environment for four weeks the alkali activated concrete samples showed only intermediate risk of corrosion.

Performance Management of Transmission Line Tower Foundations against Corrosion by Non Destructive Testing

In this paper, corrosion in overhead line foundations in different field environmental conditions (plain, agricultural and coastal/industrial region) have been detected by non-destructive test methods such as Half-cell potential test, Ultrasonic pulse velocity test, Rebound hammer test, chemical analysis of soil and Transmission Line Tower (TLT) footing concrete samples and scanning electron microscope (SEM) analysis of deteriorated tower footing concrete. The collected soil samples have been analyzed for chemicals and the TLT coping concrete samples have been tested using scanning electron microscope. The correlation between the test values, mineralogical composition of soil and concrete samples at tower footing level is presented.

Study on Graphite Powder as Conductive Pigments for Impressed Current Cathodic Protection System using Carbon Fiber Reinforced Polymer Anode

The use of Carbon Fiber Reinforced Polymer (CFRP), for both strengthening material and anode for Impressed Current Cathodic Protection (ICCP) system, is being investigated. The focus of this study is to develop the epoxy that has good bond strength and electrical conductivity. Graphite powder is used as conductive pigments with percentage ranges from 7.5% to 17.5%. All specimens were partially submerged in 5% NaCl solution and induced with electrical current of 10 mA/m2 and 20 mA/m2 for 30 days. An average potential increase of 200 mV was recorded using half cell potential test. The application of 30 days ICCP up to current density of 20 mA/m2 did not affect the bond strength significantly and still complies with ACI recommendation. However, graphite content of more than 15% are found to be not workable and the bond strength is greatly reduced to less than 1 MPa This study concluded that the recommended graphite powder content shall be in the range of 10% to 15%.

Condition Assessment and Structural Audit Before and After Repair of Fire Damaged Structure and Ansys Simulation of Column Jacketing

This study give details about the rehab process of fire damaged reinforced concrete buildings in basically three categories; condition evaluation, decision making, rehabilitation & retrofitting. Evaluation process of damaged building is based on understanding of condition survey and condition assessment of fire damaged structure. Condition survey includes detailed visual inspection of building whereas condition assessment includes non-destructive testing of building (such as Rebound Hammer test, Ultrasonic Pulse Velocity test, Carbonation test, pH test, Half Cell Potential test etc.). Based on survey and assessment, various repair and retrofitting schemes have been suggested. RC members often need strengthening to raise their capacity to sustain the applied load. This research investigates the behavior of RC columns strengthened using RC jacket technique. A finite element model was stimulated in ANSYS WORKBENCH to study the performance of these columns with and without jacketing, which has been designed for static loading. Based on ansys simulation and Comparison of test result before and after jacketing, it can be said that structure is safe in static loading condition

Influence of red mud on mechanical and durability performance of self-compacting concrete.

Red mud is a hazardous waste material produced during alkaline leaching of bauxite in the Bayer process. This study proposed the use of red mud to replace fly ash in self-compacting concrete (SCC) and the influences of red mud on fresh and hardened properties, and durability performances of SCC were studied. The fresh concrete results show that red mud had a slight negative impact on the fresh properties of SCC. The hardened concrete results show that the mechanical strength of concrete increased with increasing of red mud content. The half-cell potential test results indicated that red mud had a significant effect on restraining the corrosion process in SCC. Compared to the control sample, the red mud samples suffered less corrosion. Cracks associated with corrosion of reinforcement were observed in RMC0 and RMC100 samples after 28 day accelerated corrosion test. The ICP-MS results showed that there's no significant difference in metal elements among the solutions regardless the red mud content in concrete.The relative corrosion rate test results suggested that red mud can suppress the corrosion current. The SCC samples consisting 75% red mud performed the best resistance to corrosion according to the results of half-cell potentials and mass loss of rebar.

Mechanical and Durability Properties of Concrete Using Dredged Marine Sand

This paper reports an experimental investigation on the mechanical and durability properties of concrete using dredged marine sand (DMS). Two sources of DMS were used and the influence of water treatment prior to mixing concrete was studied. Compressive strength, tensile strength and elastic modulus of concrete with DMS were evaluated and compared with concrete made of river sand. The corrosion performance of reinforced concrete using sea dredged aggregate was examined by half-cell potential test. The results showed that the grading of DMS is suitable for concrete production. The compressive strength values of concrete specimens made with DMS are slightly higher than that of concrete made with RS. The water cleaning method is effective to minimize the chance of steel corrosion by reducing the chloride content in DMS aggregates. The results from half-cell potential test indicated that the potential values of specimens with DMS are comparable to that of specimens with RS and hence the possibility of corrosion is low. The study revealed that DMS soon after washing, could be used as an alternative to river sand.