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This research is aimed at studying the corrosion rates of carbon and weathering steels due to exposure at three urban exposure sites and the characteristics of corrosion products of carbon steel in Yangon, Myanmar. The ISO 9223 standard was used to classify the corrosion aggressiveness of the atmosphere. There is a high level of time of wetness (TOW) class which is τ4 in the south and τ3 in the central part of Myanmar. At the recent exposure sites in Myanmar, the atmospheric impurities are low, so the corrosion rates of carbon and weathering steels are mainly governed by TOW. The corrosion rates of test sites fall into the ISO C2 category. It appears that corrosion kinetics fit the power model well, since the correlation coefficient is high. Various morphologies of corrosion products including globular, flowery, and sandy lepidocrocite emerged in the early stage of exposure. The longer TOW conditions resulted in the formation of lepidocrocite and goethite. The growth of goethite products on carbon steel was discovered after nine months of exposure.

Pultrusion is an easy molding method of fiber-reinforced polymer (FRP) to obtain a long composite material with a uniform cross-section at relatively low cost. In some cases, pultruded FRPs are now used in bridges and deck projects. Since the application of pultruded FRP as a structural material is increasing, a study on the durability of pultruded FRP under outdoor conditions is necessary in terms of safety. Some studies have shown that pultruded glass fiber-reinforced polymer (GFRP) exhibits a slight reduction in mechanical properties during outdoor exposure. Since pultruded GFRP consists of multi-layers, the change of mechanical properties in each layer is important to understand. In this study, an outdoor exposure test on pultruded GFRP for 10 years was conducted with three types of pultruded GFRP, which have different laminate systems, including surface-coated specimens of each type. Changes of strength and elastic modulus due to outdoor exposure were discussed with a focus on the contribution of each layer based on the rule of mixtures. [ABSTRACT FROM AUTHOR]