Previous studies have demonstrated the high performance of the concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs) as a stay-in-place formwork and confining material for concrete structures. However, there are several concerns related to the behavior of CFFT as a protective jacket against harsh environmental effects. The environmental effects such as freeze-thaw cycles and deicing salt solutions may affect materials properties, which may affect the structural response of CFFT members as well. This paper presents the test results of experimental investigation on the durability of short- and long-term behaviors of CFFT members. Test variables included the effect of confining using GFRP tubes, freeze-thaw cycles exposure in salt water, and the number of freeze-thaw cycles. CFFT cylinders (150 × 300？mm) were prepared and exposed to 100 and 300 freeze-thaw cycles in salt water condition. Then, pure axial compression tests were conducted in order to evaluate the performance of specimens due to freeze-thaw exposure, by comparing the stress-strain behavior and their ultimate load capacities. Test results indicated that the confinement using CFFT technique significantly protected the concrete when subjected to freeze-thaw exposure. 1. Introduction Corrosion of steel reinforcement causes continual degradation to the worldwide infrastructures, and it has prompted the need for challenges to those involved with reinforced concrete structures. Recently, the use of fiber-reinforced polymer (FRP) tubes as structurally integrated stay-in-place forms for concrete members, such as beams, columns, bridge piers, piles, and fender piles, has emerged as an innovative solution to the corrosion problem. In such integrated systems, the FRP tubes may act as a permanent form, often as a protective jacket for concrete, and especially as external reinforcement in the primary and secondary directions such as for confinement. Furthermore, the use of concrete-filled FRP tubes (CFFTs) technique is predicated on performance attributes linked to their high strength-to-weight ratios, expands the service life of structures, and enhances corrosion resistance, and potentially high durability. Recently, the CFFT technique has become an adapted structural system for different concrete structures. Therefore, extensive research programs have been conducted to investigate the behavior of concrete columns confined with FRP tubes under pure compression load [1–3]. However, there is a lack of the experimental work regarding the durability effects. Short- and long-term durability of the CFFT
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