Durability of seawater and sea sand concrete and seawater and sea sand concrete-filled fibre-reinforced polymer/stainless steel tubular stub columns

This article presents an experimental investigation on the durability behaviour of seawater sea sand concrete and seawater sea sand concrete-filled fibre-reinforced polymer/stainless steel tubular stub columns. Effects of NaCl of seawater on the strength of seawater sea sand concrete and on the deterioration of fibre-reinforced polymer were studied. Accelerated degradation tests were conducted on fibre-reinforced polymer rings exposed to a combined environment of 3.5% NaCl solution and seawater sea sand concrete. Obvious hoop strength reductions were observed in glass fibre-reinforced polymer and basalt fibre-reinforced polymer rings after 6-month exposure at 60 degrees C. Seawater sea sand concrete-filled glass fibre-reinforced polymer tubular stub columns were exposed to an indoor environment (i.e. aged in air at room temperature) for a maximum duration of 2.5 years and no degradation was found by comparing the axial compressive test results from unexposed and exposed specimens. Seawater sea sand concrete-filled stainless steel tubes did not show any deterioration in strength after a 2.5-year exposure to an indoor environment or a 1.5-year immersion in NaCl solution. This study indicated that a hydrothermal environment (e.g. full immersion in solution) is much more aggressive to fibre-reinforced polymer than a dry environment. The reliability of using accelerated degradation test data to estimate the long-term performance of fibre-reinforced polymer-related structures in a real environment may need further research.

Automated summary

This study conducted experimental research on the durability behavior of seawater sea sand concrete, fiber-reinforced polymer, and stainless steel materials in different environments. The results showed that the hydrothermal environment had a greater impact on fiber-reinforced polymer, while stainless steel filled with seawater sea sand concrete exhibited stable performance.