5 research outputs found
Inhibition and Compressive-Strength Performance of Na₂Cr₂O₇ and C₁₀H₁₄N₂Na₂O₈.2H₂O in Steel-Reinforced Concrete in Corrosive Environments
No full textThis paper studied corrosion-inhibition and compressive-strength performances of NaThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Electrochemical performance of sodium dichromate partial replacement models by triethanolamine admixtures on steel-rebar corrosion in concretes
No full textThis paper studies electrochemical performance of partial replacement models of sodium dichromate (Na2Cr2O7) inhibitor by triethanolamine (C6H15NO3) admixtures on the corrosion of steel-rebar embedded in concrete immersed in corrosive environments. For these, 3.5% NaCl and 0.5M H2SO4 media were employed for respectively simulating saline/marine and industrial/microbial corrosive test-environments. Test-results of electrochemical monitoring techniques were subjected to statistical modelling of probability distribution fittings, goodness-of-fit tests and analyses for detailing admixture performance in steel-reinforced concretes. Results from these identified 6 g Na2Cr2O7 + 2 g C6H15NO3 and the 2 g Na2Cr2O7 + 6 g C6H15NO3 partial Na2Cr2O7 replacement admixtures with excellent inhibition efficiencies, η = 91.7% and η = 90.0%, respectively in the NaCl-immersed concretes. Also, the 2 g Na2Cr2O7 + 6 g C6H15NO3 exhibited inhibition efficiency η = 52.5% that lagged behind η = 72.0% of 8 g Na2Cr2O7 but which both represent good efficiency criteria in the H2SO4-immersed concretes. © 2013 by ESG
Methods of ASTM G16 and conflicts in corrosion test data: Case study of NaNO2 effectiveness on steel-rebar corrosion
No full textIn this paper, applications of the methods of ASTM G16 for addressing inherent conflicts in laboratory measurements of corrosion test data were studied, using the inhibiting effect of NaNO2 on the corrosion of concrete steel-rebar for the case study. For this, electrochemical monitoring techniques were employed for studying effectiveness of different concentrations of NaNO2 admixture in replicated concrete samples immersed in NaCl and in H2SO4 media for an experimental period of sixty-eight days. The corrosion test data from this experimental setup were subjected to the probability density fittings of the Normal and the Weibull functions as well as to significance testing methods of ASTM G16-99 R04 specifications. Results identified 10g (0.1208M) NaNO2 admixture with optimal inhibition efficiency model, η = 88.38±4.62%, in the saline/marine simulating environment and the 8 g (0.0966M) NaNO2 admixture with optimum effectiveness, η = 13.51±83.48%, in the acidic environment. The techniques of ASTM G16 adequately identified and addressed conflicting effectiveness from the test data of NaNO2 admixtures in the studied test environments.
[email protected]
Probability density fittings of corrosion test-data: Implications on C6H15NO3 effectiveness on concrete steel-rebar corrosion
No full textIn this study, corrosion test-data of steel-rebar in concrete were subjected to the fittings of the Normal, Gumbel and the Weibull probability distribution functions. This was done to investigate the suitability of the results of the fitted test-data, by these distributions, for modelling the effectiveness of C6H15NO3, triethanolamine (TEA), admixtures on the corrosion of steel-rebar in concrete in NaCl and in H2SO4 test-media. For this, six different concentrations of TEA were admixed in replicates of steel-reinforced concrete samples which were immersed in the saline/marine and the microbial/industrial simulating test-environments for seventy-five days. From these, distribution fittings of the non-destructive electrochemical measurements were subjected to the Kolmogorov-Smirnov goodness-of-fit statistics and to the analyses of variance modelling for studying test-data compatibility to the fittings and testing significance. Although all fittings of test-data followed similar trends of significant testing, the fittings of the corrosion rate test data followed the Weibull more than the Normal and the Gumbel distribution fittings, thus supporting use of the Weibull fittings for modelling effectiveness. The effectiveness models on rebar corrosion, based on these, identified 0.083% TEA with optimal inhibition efficiency, η = 72.17± 10.68%, in NaCl medium while 0.667% TEA was the only admixture with positive effectiveness, η = 56.45±15.85%, in H2SO4 medium. These results bear implications on the concentrations of TEA for effective corrosion protection of concrete steel-rebar in saline/marine and in industrial/microbial environments. © 2014 Indian Academy of Sciences
Nigerian Journal of Banking and Financial Issues (NJBFI): THE IMPACT OF SUSTAINABILITY ACCOUNTING ON THE COMMITMENT TO CORPORATE SOCIAL RESPONSIBILITY OF LISTED OIL AND GAS COMPANIES IN NIGERIA
No full textThis study examines the impact of sustainability accounting on the commitment to Corporate Social Responsibility (CSR) of listed oil and gas companies in Nigeria. The purpose of this research is to establish the influence of the Global Reporting Initiative (GRI) provisions on the commitment to corporate social responsibility among listed oil and gas firms in Nigeria. An ex post facto research design was employed while data was sourced from the annual reports of 7 listed oil and gas firms in Nigeria for a period of 6 years (2017 – 2022). The data was analyzed using descriptive statistics and Pearson correlation analysis while the hypotheses were tested using multiple regression analysis with the aid of E-views Statistical Package. The empirical results revealed that compliance to Global reporting Initiative (GRI) social provision has a negative but significant effect on commitment to CSR, compliance to GRI governance provision has a positive but significant effect on commitment to CSR and compliance to GRI environmental provision has a positive but insignificant effect on commitment to CSR. It is recommended that standard setters develop guidelines to meet local context, country differences and it is suggested that future research should consider other sectors, regions and factors that can influence CSR practices
