A comprehensive assessment of durability and service life prediction of concrete structures in the simulated tidal zone of the South China Sea considering measures to enhance concrete durability

Abstract

The island and reef area in the South China Sea is characterized by high temperature, high salinity, high humidity and windiness, which can accelerate the deterioration of concrete structures, requiring some measures to improve the durability of concrete. To improve the poor durability of concrete structures in the tidal zone of island and reef area in the South China Sea, the influence of multiple factors on concrete structures is investigated. The tests of mass, ultrasonic velocity, flexural strength and chloride ion content are used to analyze the deterioration of concrete and the service life of concrete structures. The results show that the performance of concrete under the simulated tidal environment of island and reef area is enhanced first and then attenuated, and the relationship of the mass retention, relative dynamic elastic modulus and strength retention between any two parameters is linear. Compared with concrete with a water cement ratio of 0.53 (C(-0.53)) in the paper, the deterioration degrees of C(-0.53) with calcium nitrite (CN), C(-0.53) with amino alcohol corrosion inhibitor (AA), C(-0.53) with hydrophobic pore-blocking ingredient corrosion inhibitor (HPA), C(-0.53) with salt crystallization inhibition (UMP), concrete with a water cement ratio of 0.31 (C-0.31) and concrete with a water cement ratio of 0.26 (C-0.26) decrease by 0.5%, 1.0%, 1.5%, 1.8%, 4.5% and 9.1% respectively. In addition, compared with only chloride diffusion coefficient, the multiparameter evaluation is more suitable for the chloride diffusion behavior in concrete under the simulated tidal environment of island and reef area. Compared with C(-0.53), the service life of CN, AA, HPA, UMP, C-0.31 and C-0.26 increase by at least 1.3 times, 1.9 times, 1.7 times, 6.7 times, 3.3 times and 5.5 times respectively. This study provides theoretical guidance and technical support for the durability of island and reef engineering.