The Experimental Research On The Interaction Between Concrete Carbonation And Chloride Ingress Under Loading

Concrete carbonation and chloride attack is always regarded as an important cause of deteriorating in service-life performance of reinforced concrete structure (RC). Loads and carbonization have a significant effect on chloride ion induced erosion. Researches on concrete carbonation, as well as the relationship of loading, carbonation and chloride salts erosion play an important role in accurately predicting the concrete structure service life performance. While in this main line, present paper focuses on the impact of the concrete carbonation, influence of loading on concrete carbonation, the interaction mechanism of carbonation on the chloride salt as well as loads of chloride erosion test. The main research works are as follows:(1) Designing a more accurate method of measuring concrete carbonation depth, and proposing the relationship of CaCO3changes with depth after concrete carbonization, Meanwhile, experimental tests revealed the microstructure impact of concrete carbonation which provides some experience and test results on the study of concrete carbonation.(2) Establishing the relationship between tensile strain and carbonation tests, under different strain carbonation test results comparing with the same conditions without the stress state, and fitting a simple function of concrete with tensile strain changes when change of carbonation depth. Based on the cracked concrete carbonation experiments, a carbonation cracks self-healing was investigated and proposed the concrete carbonation self-healing theory with time. Environmental scanning electron microscope (ESEM) and energy dispersive analyzer (EDS) were used to observe and analyze the extent of crack self-healing through the experiment by monitoring cracks in CaCO3of formation process based on the carbonation reaction principle, the establishment of cracks with the changes in the numerical solution of the carbonization process. Based on Fick’s law and diffusion transfer principle, establishing the diffusion coefficient of carbonation cracked concrete along the crack depth. Furthermore, ANSYS and experimental verification are used to analysis the crack width change perpendicular to the direction of the crack depth carbonation extent and adaptability of the model.(3) In order to analysis the impact of carbonization on the transfer of moisture and chloride ions, carbonation, chloride binding capacity of concrete, capillary water absorption, experiments were conducted to establish a theoretical model of the influence of carbonation of concrete on chloride ion transport.(4) Consider different pouring direction stirrup positions, stirrup corrosion state of chloride ion distribution as well as the impact of the steel corrosion, salt fog environment considering the load coupling corroded reinforced concrete chlorine ion distribution and rust development of the state of the in-depth discussion, which contributes to the durability design of reinforced concrete structures in marine atmosphere zone in a foreshadowing role.