METHODS OF ASTM G16 AND CONFLICTS IN CORROSION TEST DATA:udCASE STUDY OF NANO2 EFFECTIVENESS ON STEEL-REBAR CORROSION

摘要

In this paper, applications of the methods of ASTM G16 for addressing inherent conflicts in laboratory measurements ofudcorrosion test data were studied, using the inhibiting effect of NaNO2 on the corrosion of concrete steel-rebar for the caseudstudy. For this, electrochemical monitoring techniques were employed for studying effectiveness of differentudconcentrations of NaNO2 admixture in replicated concrete samples immersed in NaCl and in H2SO4 media for anudexperimental period of sixty-eight days. The corrosion test data from this experimental setup were subjected to theudprobability density fittings of the Normal and the Weibull functions as well as to significance testing methods of ASTMudG16-99 R04 specifications. Results identified 10g (0.1208M) NaNO2 admixture with optimal inhibition efficiencyudmodel, η = 88.38±4.62%, in the saline/marine simulating environment and the 8 g (0.0966M) NaNO2 admixture withudoptimum effectiveness, η = 13.51±83.48%, in the acidic environment. The techniques of ASTM G16 adequatelyudidentified and addressed conflicting effectiveness from the test data of NaNO2 admixtures in the studied testudenvironments.