Effects of dissolved oxygen (DO) in seawater on microbial corrosion of concrete: Morphology, composition, compression analysis and transportation evaluation

•Dissolved oxygen (DO) would promote bacterial generation and biofilm formation;•Biofilm acts as a physical barrier to prevent calcium ions’ leaching;•Formation of gypsum and ettringite during MICC would enhance the mechanical compression of concrete during early stage;•Sufficient DO in seawater would inhibit the chloride ion penetration of concrete compared with low DO content.