In order to quantitatively describe the local corrosion process of steel bars in cracked concrete area, a new two-staged utility model is established, and the effect of transverse cracks on the reinforcement corrosion...In order to quantitatively describe the local corrosion process of steel bars in cracked concrete area, a new two-staged utility model is established, and the effect of transverse cracks on the reinforcement corrosion is analyzed from the angle of long-term service performance evaluation for reinforced concrete structure. Moreover, based on the principle of spectral analysis for environmental action of concrete, an equivalent relationship is established between the corrosion rate in the natural environment and that under the standard temperature and relative humidity condition according to the principle of equivalent annual corrosion depth. Comparison between the inspection results from some references and the calculated values by the two- staged utility model validates the feasibility of the proposed model. The model was applied to Chinese Railway Track System （CRTS） Ⅱ ballastless track slab with transverse dummy joints, from which satisfactory results of corrosion degree of steel bars were obtained.展开更多
In the present work,a new transient calculation method for parameters that can be used to evaluate the ability of oxygen control in a non-isothermal lead-bismuth eutectic(LBE)loop with solid-phase oxygen control was p...In the present work,a new transient calculation method for parameters that can be used to evaluate the ability of oxygen control in a non-isothermal lead-bismuth eutectic(LBE)loop with solid-phase oxygen control was proposed.It incorporates the dissolution process of PbO particles and the oxygen mass transfer process,and an optimized method was used for finding out the optimized oxygen mass transfer coefficient.In numerical terms,three mass transfer models were simultaneously applied,and comparisons of calculated and experimental results from the CRAFT loop indicated that the optimized calculation method and these new oxygen mass transfer models were correct and applicable to other LBE loops.Through this calculation method,we aimed to optimize prediction of the distribution of oxygen and iron concentrations,time taken to establish the steady state of oxygen,and maximum dissolution/precipitation rates of corrosion products and corrosion depth across the entire LBE loop.We hope that this work will provide a potential reference for designing a more intelligent oxygen control system in the future.展开更多
基金Funded by the Natural Science Foundation of China(Nos.51378501,51174291,51109121,51278495,51008312)the Key Technological Research and Development Programs of Ministry of Railways,China(No.2008G031-18)
文摘In order to quantitatively describe the local corrosion process of steel bars in cracked concrete area, a new two-staged utility model is established, and the effect of transverse cracks on the reinforcement corrosion is analyzed from the angle of long-term service performance evaluation for reinforced concrete structure. Moreover, based on the principle of spectral analysis for environmental action of concrete, an equivalent relationship is established between the corrosion rate in the natural environment and that under the standard temperature and relative humidity condition according to the principle of equivalent annual corrosion depth. Comparison between the inspection results from some references and the calculated values by the two- staged utility model validates the feasibility of the proposed model. The model was applied to Chinese Railway Track System （CRTS） Ⅱ ballastless track slab with transverse dummy joints, from which satisfactory results of corrosion degree of steel bars were obtained.
基金supported by the National Natural Science Foundation of China (Nos. 12027813 and 12105101)the Fundamental Research Funds for the National key project (No. 2019YFB1901301)
文摘In the present work,a new transient calculation method for parameters that can be used to evaluate the ability of oxygen control in a non-isothermal lead-bismuth eutectic(LBE)loop with solid-phase oxygen control was proposed.It incorporates the dissolution process of PbO particles and the oxygen mass transfer process,and an optimized method was used for finding out the optimized oxygen mass transfer coefficient.In numerical terms,three mass transfer models were simultaneously applied,and comparisons of calculated and experimental results from the CRAFT loop indicated that the optimized calculation method and these new oxygen mass transfer models were correct and applicable to other LBE loops.Through this calculation method,we aimed to optimize prediction of the distribution of oxygen and iron concentrations,time taken to establish the steady state of oxygen,and maximum dissolution/precipitation rates of corrosion products and corrosion depth across the entire LBE loop.We hope that this work will provide a potential reference for designing a more intelligent oxygen control system in the future.
