Existing studies on chloride ion transport in concrete under compressive load had rarely incorporated the influence of the dry–wet time ratio, even though this ratio was a key factor affecting chloride penetration in coastal concrete structures subjected to periodic drying–wetting cycles. This study was therefore motivated to fill this gap and to provide more reliable theoretical support for the durability assessment of such engineering structures. A series of accelerated chloride ion penetration experiments was conducted on concrete under compressive load with different dry–wet time ratios. The effects of the dry–wet time ratio, compressive stress level, and exposure environment on chloride ion transport in concrete were analyzed. A chloride ion diffusion coefficient model that accounted for both the dry–wet time ratio and the compressive stress level was then established and validated. The results showed that the enhancing effect of the dry–wet time ratio on chloride ion transport became significant under relatively high compressive stress. When the dry–wet time ratio was 7:1, the convection zone depths of concrete specimens under no stress and compressive stress were both 5 mm. Moreover, when the compressive stress level was 0.5 times the compressive strength and the dry–wet time ratio was 7:1, the chloride concentration of the specimens increased by an average of 756.4% compared with that under natural immersion.

The objective of this study was to experimentally quantify and analytically model chloride ion transport in high-performance concrete incorporating single and binary mineral admixtures under sustained compressive loading, thereby improving durability prediction for load-bearing concrete exposed to chloride environments. A series of accelerated chloride transport experiments was conducted on high-performance concrete subjected to sustained compressive loading. The surface strain evolution of concrete was investigated under different compressive stress ratios and admixture dosages. The effects of the admixture dosage and sustained compressive stress ratio on chloride distribution were analyzed. A chloride diffusion coefficient model that incorporated sustained compressive loading and composite mineral admixtures was established, and its validity was verified. The influences of key parameters on chloride transport in binary-blended high-performance concrete were further discussed. The results showed that the strain of ordinary concrete specimens was the largest, followed by that of high-performance concrete with a single admixture of fly ash or silica fume, and the strain of high-performance concrete with double admixtures of fly ash and silica fume was the smallest. The chloride concentration in concrete first decreased and then increased with the increase in compressive stress level. The largest change amplitude was observed in ordinary concrete, and the smallest was in high-performance concrete with double admixtures of fly ash and silica fume. An increase in the time decay coefficient caused the chloride concentration in binary-blended high-performance concrete to decrease first and then increase. When the fly ash content was kept constant, the chloride concentration gradually decreased with increasing silica fume content. When the silica fume content reached 17%, the chloride concentration at a diffusion depth of 11 mm approached zero.

To investigate the effects of loading type and stirrup arrangement on the corrosion and deterioration characteristics of reinforced concrete beams, constant current accelerated corrosion tests were conducted under no load, uniaxial compressive load, and biaxial compressive load conditions, with specimens without stirrups serving as the control group. A comparative analysis was performed on the overall corrosion of the top surface of the concrete beams, the expansion strain of the concrete beams, and the crack distribution on the top surface of the beams with and without stirrups. The characteristics of the protective layer spalling in the concrete beams under different loading conditions were also discussed. The results showed that the expansion strain of specimens with normal stirrups was significantly higher than that of specimens without stirrups. Under uniaxial compressive loading, the expansion strain was lower compared to the no-load specimens. Under biaxial loading at 15% of the compressive strength, the expansion strain was minimal, suggesting that the loading compaction effect suppressed crack propagation. Furthermore, under biaxial loading, as the load level increased, the Poisson effect intensified the tensile deformation in the vertical direction, causing cracks to propagate rapidly. The extent and depth of the spalling of the protective layer increased significantly, exhibiting more severe deterioration characteristics.