Abstract The aim of this study was to evaluate the corrosion resistance of Ni-bearing carbon steels used in outdoor structures from short-term experimental techniques and compare with the long-term field test data. The carbon steels studied were two experimental steels, produced in a pilot plant, and alloyed with nickel, copper, silicon and molybdenum (Ni-Cu-Si and Ni-Cu-Mo-Si steels), one carbon steel and one commercial Cr-Cu-Si alloyed steel. The atmospheric corrosion resistance of low alloyed carbon steels was evaluated by using field tests for eight years in a marine station, and their electrochemical behavior was studied in laboratory using the electrochemical impedance spectroscopy in aqueous electrolytes containing chlorides. The Ni-Cu-Si and Ni-Cu-Mo-Si steels showed the lowest corrosion rates which decreased as the time increased after eight years of exposure in marine atmosphere. The classification of the low alloyed steels considering the corrosion resistance using electrochemical tests in 10% m/v NaCl solution was similar to rating using field tests in a marine station.

Abstract The effect of short-term oxidation, evaluated by using a Rolling Thin Film Oven Test, and the effect of weathering aging on the oxidation process of hydrated lime modified asphalts were studied. Hydrated lime (HL) has been known as an additive for asphalt mixtures and is now considered as a binder additive that increases asphalt mixture durability. HL was added to the binder in contents of 5, 10, 20, and 30 wt.%. The HL modified binders were aged by using the Rolling Thin Film Oven Test and weathering tests with xenon radiation. A storage stability test by measuring the softening points of HL modified binders was performed. The Thin Layer Chromatography with Flame Ionization Detection (TLC-FID) analysis was used to determine the fractions of resins, aromatics, asphaltenes and saturates of the binders. The aging of HL modified binders was evaluated by using Fourier transform infrared spectroscopy. According to the stability test, a hydrated lime concentration value close to 20 wt.% is the critical point at which there is a risk of segregation of the asphalt binder and hydrated lime during transportation and storage. For the sample weathering aged for 250 hours, a decrease of saturated and aromatic fractions, furthermore an increase in asphaltenes were observed for all samples. Results have shown that additions of 10 wt.% of hydrated lime in asphalt binders resulted in a higher photodegradation resistance among the other asphalt mixtures considering the carbonyl index, stability test and colloidal instability test results.