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Mohammed Maslehuddin - One of the best experts on this subject based on the ideXlab platform.
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long term effect of sulfate ions and associated cation type on chloride induced Reinforcement Corrosion in portland cement concretes
Cement & Concrete Composites, 2002Co-Authors: Hamoud A.f. Dehwah, Mohammed Maslehuddin, Simon A. AustinAbstract:This paper reports the influence of sulfate concentration on chloride-induced Reinforcement Corrosion in Portland cement concretes (with C3A varying from 3.6% to 9.65%). The concrete specimens were exposed to mixed chloride and sulfate solutions for a period of 1200 days. The chloride was fixed at 5% NaCl for all solutions, while the sulfate concentration was varied to represent that noted in the sulfate-bearing soil and ground water. The study included an assessment of the effect of cation type associated with sulfate ions, namely Na+ and Mg2+, on chloride-induced Reinforcement Corrosion, an important factor that has received little attention. Reinforcement Corrosion was evaluated by measuring Corrosion potentials and Corrosion current density at regular intervals. The results indicate that the presence of sulfate ions in the chloride solution did not influence the time to initiation of chloride-induced Reinforcement Corrosion, but the rate of Corrosion increased with increasing sulfate concentration. Further, the rate of chloride-induced Reinforcement Corrosion in the concrete specimens exposed to sodium chloride plus magnesium sulfate solutions was more than that in the concrete specimens exposed to sodium chloride plus sodium sulfate solutions.
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Effectiveness of concrete surface treatmentmaterials in reducing chloride-induced Reinforcement Corrosion
Construction and Building Materials, 1997Co-Authors: Mohammed K. Ibrahim, Mohammed Maslehuddin, A. S. Al-gahtani, A.a. AlmusallamAbstract:Abstract The effectiveness of concrete surface treatment materials, such as silane, siloxane, acrylic coating, etc., in reducing chloride-induced Reinforcement Corrosion was investigated. Two sets of reinforced concrete specimens were cast. In the first set, Reinforcement Corrosion was accelerated by impressing an anodic potential of 2 V and the time to cracking was monitored. The second set of concrete specimens were immersed in the chloride solution and Reinforcement Corrosion was monitored by measuring Corrosion potentials and Corrosion current density. Among the surface treatment materials investigated, silane, silane/siloxane with top coat and acrylic coating were effective in reducing the rate of Reinforcement Corrosion. Furthermore, the data developed in this investigation indicated that the performance of coatings can be quickly evaluated using impressed current technique.
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Evaluation of a surface coating in retarding Reinforcement Corrosion
Construction and Building Materials, 1996Co-Authors: H. Saricimen, Mohammed Maslehuddin, Asfaha Iob, Omar A. EidAbstract:Abstract This paper reports results of an investigation conducted to evaluate the effectiveness of a concrete surface coating in reducing the permeability of concrete and retarding Reinforcement Corrosion. An underground structure located on the Arabian Gulf coast was coated with this coating and the properties of concrete and Reinforcement Corrosion were monitored for a period of two years. An improvement in the physical properties of concrete was indicated due to the application of the coating. The Corrosion potentials indicated an increase in the Corrosion activity in the early period of application in certain components. At later periods, however, the Reinforcement Corrosion activity was noticeably lower than that in the pre-application condition, indicating the usefulness of the coating in retarding Reinforcement Corrosion.
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The influence of Arabian Gulf environment on mechanisms of Reinforcement Corrosion
1994Co-Authors: Mohammed MaslehuddinAbstract:The reduction in the useful-service life of reinforced concrete construction in the Arabian Gulf is attributed to Reinforcement Corrosion. While this phenomenon is primarily related to chloride ions, the concomitant pressure of sulfate salts may accelerate the deterioration process. Another factor which might influence Reinforcement Corrosion is the elevated ambient temperature. While few studies have been conducted to evaluate the individual effect of sulfate contamination and temperature on chloride binding and Reinforcement Corrosion, the synergistic effect of these factors on concrete durability, viz.-a-viz., Reinforcement Corrosion, needs to be evaluated. Further, the environmental conditions of the Arabian Gulf are also conducive for accelerated carbonation. However, no data are available on the concomitant effect of chloride-sulfate contamination and elevated temperature on the carbonation behaviour of plain and blended cements.This study was conducted to evaluate the conjoint effect of chloride-sulfate contamination and temperature on the pore solution chemistry and Reinforcement Corrosion. The effect of chloride-sulfate contamination and elevated temperature on carbonation in plain and blended cements was also investigated. Pore solution extraction and analysis, X-ray diffraction, differential thermal analysis, scanning electron microscopy, DC linear polarization resistance and AC impedance spectroscopy techniques were utilized to study the effect of experimental parameters on chloride binding, Reinforcement Corrosion and carbonation.The results indicated that the concomitant presence of chloride and sulfate salts and temperature significantly influences the durability performance of concrete by: (i) decreasing the chloride binding, (ii) increasing Reinforcement Corrosion, and (iii) accelerating the carbonation process. To avoid such deterioration, it is advisable to minimize both chloride and sulfate contamination contributed by the mixture ingredients. Due to the known harmful role of sulfate ions in decreasing the chloride binding and increasing Reinforcement Corrosion, limits on allowable sulfate contamination in concrete should also be established.
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The effect of chloride and sulfate ions on Reinforcement Corrosion
Cement and Concrete Research, 1993Co-Authors: Omar S. Baghabra Al-amoudi, Mohammed MaslehuddinAbstract:Abstract The effect of chloride, sulfate and chloride-sulfate solutions on Corrosion of steel embedded in cement paste has been investigated. The Reinforcement Corrosion was evaluated by measuring Corrosion potentials and Corrosion current density using D.C. linear polarization resistance technique. Results indicate that the Corrosion activity was very minimal in specimens immersed in pure sulfate solution. The Reinforcement Corrosion activity was found to be higher in specimens immersed in chloride-sulfate solutions as compared to those immersed in pure chloride solution. The Corrosion rate was observed to be doubled when the sulfate concentration in 15.7% Cl − solution was raised from 0.55 to 2.1%.
Martin Cullen - One of the best experts on this subject based on the ideXlab platform.
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Structural performance of RC beams under simultaneous loading and Reinforcement Corrosion
Construction and Building Materials, 2013Co-Authors: Martin CullenAbstract:Abstract The paper aims to investigate the influence of simultaneous loading and Reinforcement Corrosion on the structural performance of concrete beams. Five reinforced concrete beams were first loaded to 60% of their strengths, and then subjected to the sustained load and Reinforcement Corrosion simultaneously, until they collapsed either due to Corrosion development or further loading. The experimental results indicate that, under the same loads, the time-dependant deflections of corroded beams increased more rapidly than those of non-corroded beam, and reached their limiting deflections prematurely. A local Corrosion of a shorter length of tensile bars decreased beam strength and ductility more greatly than an extensive Corrosion of a longer length of bars. Simultaneous loading and Corrosion impairs beam strength and ductility more significantly than separate one. Either a further Corrosion or an occasional over-loading or both are likely to cause concrete structures under service loads to collapse suddenly without significant deflection.
A.a. Almusallam - One of the best experts on this subject based on the ideXlab platform.
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Effectiveness of concrete surface treatmentmaterials in reducing chloride-induced Reinforcement Corrosion
Construction and Building Materials, 1997Co-Authors: Mohammed K. Ibrahim, Mohammed Maslehuddin, A. S. Al-gahtani, A.a. AlmusallamAbstract:Abstract The effectiveness of concrete surface treatment materials, such as silane, siloxane, acrylic coating, etc., in reducing chloride-induced Reinforcement Corrosion was investigated. Two sets of reinforced concrete specimens were cast. In the first set, Reinforcement Corrosion was accelerated by impressing an anodic potential of 2 V and the time to cracking was monitored. The second set of concrete specimens were immersed in the chloride solution and Reinforcement Corrosion was monitored by measuring Corrosion potentials and Corrosion current density. Among the surface treatment materials investigated, silane, silane/siloxane with top coat and acrylic coating were effective in reducing the rate of Reinforcement Corrosion. Furthermore, the data developed in this investigation indicated that the performance of coatings can be quickly evaluated using impressed current technique.
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EFFECT OF Reinforcement Corrosion ON BOND STRENGTH
Construction and Building Materials, 1996Co-Authors: A.a. Almusallam, A. S. Al-gahtani, Abdur Rauf Aziz, RasheeduzzafarAbstract:Abstract The effect of Reinforcement Corrosion on the bond strength between steel and concrete was investigated. The bond behaviour of reinforced concrete elements, including the ultimate bond strength, free-end slip, and the modes of failure in precracking, cracking and postcracking stages was studied. Also, the effect of different crack widths and the rib profile degradation for various degrees of Corrosion on the bond strength were evaluated. In order to establish different levels of Corrosion, a calibration curve establishing a relationship between the duration of the impressed current and the corresponding degree of Corrosion was prepared. The magnitude of Corrosion was measured as gravimetric loss in weight of the reinforcing bars. The results indicate that in the precracking stage (0–4% Corrosion) the ultimate bond strength increases, whereas the slip at the ultimate bond strength decreases with an increase in the degree of Corrosion. The degradation of bond results from the crushing of concrete keys near the bar lugs. When Reinforcement Corrosion is in the range of 4 to 6%, the bond failure occurs suddenly at a very low free-end slip. At this level of Reinforcement Corrosion, a large slip was noted as the ultimate failure of the bond occurred due to the splitting of the specimens. Beyond 6% rebar Corrosion, the bond failure resulted from a continuous slippage of the rebars. The ultimate bond strength initially increased with an increase in the degree of Corrosion, until it attained a maximum value of 4% rebar Corrosion after which there was a sharp reduction in the ultimate bond strength up to 6% rebar Corrosion. Beyond the 6% rebar Corrosion level the ultimate bond strength did not vary much even up to 80% Corrosion. In terms of the effect of rib profile, a sharp reduction in the bond strength was initiated when its degradation exceeded 25%. This decrease in bond strength continued up to 45%. Thereafter, there was no significant effect of the rib profile degradation on the bond strength.
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EFFECT OF Reinforcement Corrosion ON FLEXURAL BEHAVIOR OF CONCRETE SLABS
Journal of Materials in Civil Engineering, 1996Co-Authors: A.a. Almusallam, A. S. Al-gahtani, Abdur Rauf Aziz, Fahd H. Dakhil, RasheeduzzafarAbstract:The effect of Reinforcement Corrosion on the flexural strength of a uniformly loaded and simply supported one-way slab was investigated. In addition to the flexural strength, the effect of different degrees of Reinforcement Corrosion on the deformational behavior, ductility, and the mode of failure of the slabs were also evaluated. The critical level of Reinforcement Corrosion that renders the strength contribution of steel negligible was evaluated by comparing the strengths of slabs with highly corroded Reinforcement with the strengths of plain concrete slabs. In order to induce different levels of Reinforcement Corrosion, a calibration curve establishing a relationship between the duration of the impressed current and Reinforcement Corrosion was prepared. The magnitude of Reinforcement Corrosion was measured as gravimetric loss in weight of the steel bars. The results indicate a sharp reduction in the ultimate flexural strength of slabs with an up to a 29 Reinforcement Corrosion; thereafter, the strengt...
Joshua Olusegun Okeniyi - One of the best experts on this subject based on the ideXlab platform.
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C10H18N2Na2O10 inhibition and adsorption mechanism on concrete steel-Reinforcement Corrosion in corrosive environments
Journal of the Association of Arab Universities for Basic and Applied Sciences, 2016Co-Authors: Joshua Olusegun OkeniyiAbstract:Abstract C10H18N2Na2O10 (ethylenediaminetetra-acetic acid disodium salt) inhibition and adsorption mechanism on the Corrosion of steel-Reinforcement Corrosion in concrete immersed in corrosive environments were investigated in this paper. For this, seven different concentrations ranging from 0% to 0.667% C10H18N2Na2O10 per weight of cement were admixed in steel-reinforced concretes immersed in saline and in acidic sulphate test-media and these were monitored using electrochemical techniques. Statistical analyses of the scatter of measured data from these, as per ASTM G16-95 R04, showed that C10H18N2Na2O10 > 0% admixtures portrayed excellent efficiency at inhibiting steel-Reinforcement Corrosion in the saline environment. However, attaining comparably high inhibition of steel-Reinforcement Corrosion in concrete immersed in the acidic sulphate environment exhibited greater dependency on high C10H18N2Na2O10 admixture concentration in the steel-reinforced concretes. Different models of adsorption isotherms bear indications of chemical adsorption, chemisorptions, as the prevalent adsorption mechanism of C10H18N2Na2O10 on steel-Reinforcement in both of the corrosive environments.
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Electrochemical Performance of Anthocleista djalonensis on Steel-Reinforcement Corrosion in Concrete Immersed in Saline/Marine Simulating-Environment
Transactions of the Indian Institute of Metals, 2014Co-Authors: Joshua Olusegun Okeniyi, C A Loto, A P I PopoolaAbstract:In this paper, electrochemical techniques were employed to study performance of different concentrations of Anthocleista djalonensis leaf-extract admixtures on the Corrosion of steel-Reinforcement in concrete immersed in 3.5 % NaCl, for simulating saline/marine environment. Analysed test-results showed that the Corrosion rate correlated directly with admixture concentration and inversely with cube of the ratio of standard deviations of Corrosion potential and Corrosion current. The 0.4167 % A. djalonensis (per weight of cement) exhibited optimal inhibition efficiency, η = 97.43 ± 1.20 %, from analysed experimental data, or 94.80 ± 3.39 %, from predicted correlation model, on steel-Reinforcement Corrosion in the medium. The other admixture concentrations also exhibited high efficiencies at inhibiting steel-Reinforcement Corrosion in the chloride contaminated environment. Isotherm fittings of the experimental and predicted performance suggest that they both obeyed the Langmuir adsorption model. Evaluated parameters from the isotherm model indicated favourable adsorption and predominant chemisorption mechanism by this environmentally-friendly inhibitor of steel-Reinforcement Corrosion in the saline/marine simulating-environment.
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electrochemical performance of anthocleista djalonensis on steel Reinforcement Corrosion in concrete immersed in saline marine simulating environment
Transactions of The Indian Institute of Metals, 2014Co-Authors: Joshua Olusegun Okeniyi, C A Loto, A P I PopoolaAbstract:In this paper, electrochemical techniques were employed to study performance of different concentrations of Anthocleista djalonensis leaf-extract admixtures on the Corrosion of steel-Reinforcement in concrete immersed in 3.5 % NaCl, for simulating saline/marine environment. Analysed test-results showed that the Corrosion rate correlated directly with admixture concentration and inversely with cube of the ratio of standard deviations of Corrosion potential and Corrosion current. The 0.4167 % A. djalonensis (per weight of cement) exhibited optimal inhibition efficiency, η = 97.43 ± 1.20 %, from analysed experimental data, or 94.80 ± 3.39 %, from predicted correlation model, on steel-Reinforcement Corrosion in the medium. The other admixture concentrations also exhibited high efficiencies at inhibiting steel-Reinforcement Corrosion in the chloride contaminated environment. Isotherm fittings of the experimental and predicted performance suggest that they both obeyed the Langmuir adsorption model. Evaluated parameters from the isotherm model indicated favourable adsorption and predominant chemisorption mechanism by this environmentally-friendly inhibitor of steel-Reinforcement Corrosion in the saline/marine simulating-environment.
Shamsad Ahmad - One of the best experts on this subject based on the ideXlab platform.
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effect of ohmic drop on accuracy of Reinforcement Corrosion rate measured using different setups
Journal of Testing and Evaluation, 2014Co-Authors: Shamsad AhmadAbstract:High resistance offered by concrete to the current applied to polarize reinforcing bars embedded in concrete during measurement of Reinforcement Corrosion rate results in Ohmic drop, which causes inaccuracy in the measured value of the Reinforcement Corrosion rate. A study on accuracies of a simple developed setup and two other commercially available setups in measuring Reinforcement Corrosion rate using the linear polarization resistance method with and without Ohmic drop compensation is reported in this paper. The good correlation between electrochemically measured Corrosion current density and gravimetrically measured percentage weight loss was taken as an indicator of accuracy of each setup. The developed setup was found to be most accurate in measuring Corrosion rate without, as well as with, Ohmic drop compensation. Both commercial setups were found to have reasonably acceptable accuracy without Ohmic drop compensation; however, both were found with unacceptable accuracy with Ohmic drop compensation.
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Reinforcement Corrosion in concrete structures its monitoring and service life prediction a review
Cement & Concrete Composites, 2003Co-Authors: Shamsad AhmadAbstract:Reinforcement Corrosion has been widely reported in the literature over the last two to three decades. It is one of the major durability problems, mainly when the rebar in the concrete is exposed to the chlorides either contributed from the concrete ingredients or penetrated from the surrounding chloride-bearing environment. Carbonation of concrete or penetration of acidic gases into the concrete, are the other causes of Reinforcement Corrosion. Besides these there are few more factors, some related to the concrete quality, such as w/c ratio, cement content, impurities in the concrete ingredients, presence of surface cracks, etc. and others related to the external environment, such as moisture, oxygen, humidity, temperature, bacterial attack, stray currents, etc., which affect Reinforcement Corrosion. The assessment of the causes and extent of Corrosion is carried out using various electrochemical techniques. Prediction of the remaining service life of a corroding RC structure is done with the help of empirical models and experimental methods. In this paper a review is presented on the mechanism of Reinforcement Corrosion, techniques utilized to monitor Reinforcement Corrosion and methodologies that are utilized for the prediction of remaining service life of structures.
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Reinforcement Corrosion in the Arabian Gulf and its prevention- a review
2003Co-Authors: Shamsad Ahmad, Omar S. Baghabra Al-amoudi, Mohammad MaslehuddinAbstract:Concrete deterioration due to Reinforcement Corrosion is a widely recognized problem faced by the construction industry. In the temperate climatic conditions, Reinforcement Corrosion is basically attributed to the use of deicer salts in the highway structures. Exposure to the other chloride and/or carbon dioxide environments in marine and industrial structures, respectively, has also contributed to Reinforcement Corrosion. In the Arabian Gulf, the problem of concrete durability, particularly that due to Reinforcement Corrosion, is mainly attributed to the environmental conditions, and poor quality of the construction materials, especially the aggregates. The environmental factors, such as temperature, and relative humidity accelerate the process of Reinforcement Corrosion. This paper provides a review of factors affecting Reinforcement Corrosion. Also, a summary of the preventive measures that should be adopted to minimize Reinforcement Corrosion is provided with the context of the research conducted in this area.