Cored concrete specimens from seawall exposed to marine environment for 22 years were evaluated by carbonation depth test,rapid chloride permeability test,absorption of water test and microstructure examination.The re...Cored concrete specimens from seawall exposed to marine environment for 22 years were evaluated by carbonation depth test,rapid chloride permeability test,absorption of water test and microstructure examination.The results show that concrete exposed to marine environment has smaller carbonation depth and carbonation depth of concrete exposed to tidal zone is less than that in splash zone.There are similar water absorption rate and chloride permeability for concrete exposed to splash zone compared with concrete exposed to splash zone removed 3mm surface layer.However,concrete exposed to tidal zone with bio-films has lower chloride permeability and water absorption rate than those of concrete exposed to tidal zone removed 3mm surface layer.In addition,Results of FE-SEM and EDAX indicate that concrete exposed to splash zone has loose structure,exposed finer aggregate and concrete exposed to tidal zone covers by dense structure of oyster cementation and shell.Microstructures analysis further verified that concrete covered with oysters and their cementation has beneficial effects to durability of concrete.展开更多
A novel Ti/MnO2 reference electrode (TMRE) used for concrete environment was fabricated by the electro-deposition method and encapsulated carefully.The properties of the electrode were characterized by open-circuit po...A novel Ti/MnO2 reference electrode (TMRE) used for concrete environment was fabricated by the electro-deposition method and encapsulated carefully.The properties of the electrode were characterized by open-circuit potential,potentiodynamic polarization behavior in synthetic concrete pore solutions and electrochemical performance in cement mortar.The experimental results indicate that the TMRE shows good stability with and without the addition of Cl-ions and desirable polarization behavior in synthetic pore solution.Results of tests in cement mortar indicate that the potential of TMRE will be stable after about 7 days.The stability and desirable polarization behavior make it a promising reference electrode for concrete environment.展开更多
基金Funded by the National Natural Science Foundation of China (No.50678053)
文摘Cored concrete specimens from seawall exposed to marine environment for 22 years were evaluated by carbonation depth test,rapid chloride permeability test,absorption of water test and microstructure examination.The results show that concrete exposed to marine environment has smaller carbonation depth and carbonation depth of concrete exposed to tidal zone is less than that in splash zone.There are similar water absorption rate and chloride permeability for concrete exposed to splash zone compared with concrete exposed to splash zone removed 3mm surface layer.However,concrete exposed to tidal zone with bio-films has lower chloride permeability and water absorption rate than those of concrete exposed to tidal zone removed 3mm surface layer.In addition,Results of FE-SEM and EDAX indicate that concrete exposed to splash zone has loose structure,exposed finer aggregate and concrete exposed to tidal zone covers by dense structure of oyster cementation and shell.Microstructures analysis further verified that concrete covered with oysters and their cementation has beneficial effects to durability of concrete.
文摘A novel Ti/MnO2 reference electrode (TMRE) used for concrete environment was fabricated by the electro-deposition method and encapsulated carefully.The properties of the electrode were characterized by open-circuit potential,potentiodynamic polarization behavior in synthetic concrete pore solutions and electrochemical performance in cement mortar.The experimental results indicate that the TMRE shows good stability with and without the addition of Cl-ions and desirable polarization behavior in synthetic pore solution.Results of tests in cement mortar indicate that the potential of TMRE will be stable after about 7 days.The stability and desirable polarization behavior make it a promising reference electrode for concrete environment.
