Study on the Performance and Service Life Prediction of Corrosion-Resistant Concrete Cut-Corner Square Piles.

Abstract

This paper addresses the issue of reduced lifespan of coastal concrete piles due to chloride ion corrosion. A combination of concrete mix optimization and pile geometry improvement measures is proposed. Based on the diffusion coefficient optimization of Fick's second law, the service life prediction of concrete piles in corrosive environments is completed. The results show that, compared to single slag incorporation and the "slag-fly ash" dual-component mix, the "slag-fly ash-corrosion inhibitor" triple-component concrete achieves a 28-day compressive strength of 67.4 MPa, and the chloride ion diffusion coefficient is reduced to 1.14 × 10^-12 m²/s, significantly improving overall performance. Finite element simulations reveal that, compared to ordinary square piles, cut-corner square piles can effectively alleviate stress concentration at the pile tip and reduce settlement. The maximum stress is 3.94 MPa, and the settlement is 22.64 mm, representing reductions of about 16.3% and 15.5%, respectively, compared to ordinary square piles. Concrete service life prediction confirms that the concrete with corrosion inhibitors has a predicted service life of 31.5 years, extending 7.4 years and 13.3 years longer than the single slag and the "slag-fly ash" dual-component groups, respectively. The "material-structure" optimization theory proposed in this study provides a theoretical basis and technical path for the long-life design of coastal engineering pile foundations.