Short-term evaluation procedures for coatings on structural steel

Abstract

This report presents the findings of the first of a two-phased study to aid the Federal Highway Administration in evaluating and selecting protective coatings for steel. The objectives of the study are to review existing short-term test procedures for selecting coatings, and to discuss analytical measurement techniques for characterizing coating systems and for monitoring coating degradation. In assessing current accelerated aging testing procedures, several deficiencies became apparent. These included the reported lack of reproducibility in the rankings for different iterations of the same short-term test and the lack of correlatability between the rankings of short-term laboratory and long-term outdoor exposure tests. It was concluded that, at the present time, coating manufacturers and users do not depend heavily on accelerated test results for making durability assessments. Instead, durability assessments are based on outdoor exposure performance. Recommendations are made to design future short-term test procedures using reliability theory.

Methodologies for predicting the service lives of coating systems

“…None of these procedures, however, has consistently produced a high correlation with longterm outdoor exposure results [Reinhart, 1958;Nowacki, 1962;Kamal, 1966;Quackenbos and Samuels, 1967;Hof&nann and Saracz, 1971;Alumbaugh and Hearst, 1975;Ellinger, 1977;Campbell et al, 1981;Lmdberg, 1982;Leidheiser, 1982; Yaseen and Raju, 1984;Chandler and Bayliss, 1985;Funke et al, 1986;Cutrone and Moulton, 1987;Simms, 1987;Masters, 1987;Wicks, 1988;Skerry et al, 1988;Himics and Pineiro, 1992]. Failure to produce a high correlation has usually been assigned to deficiencies in laboratory-based aging experiments and, in particular, the inability to design a laboratory-based experiment containing a "balance of exposure conditions" [Stieg, 1966;Ellinger, 1977;Skerry et al, 1988].…”

Methodologies for predicting the service lives of coating systems

“…None of these procedures, however, has consistently produced a high correlation with longterm outdoor exposure results [Reinhart, 1958;Nowacki, 1962;Kamal, 1966;Quackenbos and Samuels, 1967;Hof&nann and Saracz, 1971;Alumbaugh and Hearst, 1975;Ellinger, 1977;Campbell et al, 1981;Lmdberg, 1982;Leidheiser, 1982; Yaseen and Raju, 1984;Chandler and Bayliss, 1985;Funke et al, 1986;Cutrone and Moulton, 1987;Simms, 1987;Masters, 1987;Wicks, 1988;Skerry et al, 1988;Himics and Pineiro, 1992]. Failure to produce a high correlation has usually been assigned to deficiencies in laboratory-based aging experiments and, in particular, the inability to design a laboratory-based experiment containing a "balance of exposure conditions" [Stieg, 1966;Ellinger, 1977;Skerry et al, 1988].…”

Methodologies for predicting the service lives of coating systems

“…None of these procedures, however, has consistently produced a high correlation with longterm outdoor exposure results [Reinhart, 1958;Nowacki, 1962;Kamal, 1966;Quackenbos and Samuels, 1967;Hof&nann and Saracz, 1971;Alumbaugh and Hearst, 1975;Ellinger, 1977;Campbell et al, 1981;Lmdberg, 1982;Leidheiser, 1982; Yaseen and Raju, 1984;Chandler and Bayliss, 1985;Funke et al, 1986;Cutrone and Moulton, 1987;Simms, 1987;Masters, 1987;Wicks, 1988;Skerry et al, 1988;Himics and Pineiro, 1992]. Failure to produce a high correlation has usually been assigned to deficiencies in laboratory-based aging experiments and, in particular, the inability to design a laboratory-based experiment containing a "balance of exposure conditions" [Stieg, 1966;Ellinger, 1977;Skerry et al, 1988].…”

Methodologies for predicting the service lives of coating systems

“…None of these procedures, however, has consistently produced a high correlation with longterm outdoor exposure results [Reinhart, 1958;Nowacki, 1962;Kamal, 1966;Quackenbos and Samuels, 1967;Hof&nann and Saracz, 1971;Alumbaugh and Hearst, 1975;Ellinger, 1977;Campbell et al, 1981;Lmdberg, 1982;Leidheiser, 1982; Yaseen and Raju, 1984;Chandler and Bayliss, 1985;Funke et al, 1986;Cutrone and Moulton, 1987;Simms, 1987;Masters, 1987;Wicks, 1988;Skerry et al, 1988;Himics and Pineiro, 1992]. Failure to produce a high correlation has usually been assigned to deficiencies in laboratory-based aging experiments and, in particular, the inability to design a laboratory-based experiment containing a "balance of exposure conditions" [Stieg, 1966;Ellinger, 1977;Skerry et al, 1988].…”