Alkali-activated concrete (AAC), as a novel green, low-carbon building material, has attracted extensive attention because it reuses industrial solid waste, reducing energy consumption and carbon emissions, and offers superior corrosion resistance, frost resistance, and high-temperature stability compared with ordinary Portland cement (OPC) concrete. In marine engineering, steel-bar corrosion caused by aggressive ions has long been a critical threat to structural durability. Fiber-reinforced polymer (FRP) bars, including glass fiber-reinforced polymer (GFRP), carbon fiber-reinforced polymer (CFRP), and basalt fiber-reinforced polymer (BFRP) bars, have emerged as ideal alternatives to steel bars because of their light weight, high tensile strength, excellent corrosion resistance, and design flexibility, thereby effectively addressing the corrosion problem in harsh marine environments.

The bond performance between FRP bars and AAC is a fundamental prerequisite for composite action in the structure. Because of the significant differences in physical and mechanical properties between FRP bars and steel bars, as well as between AAC and OPC, traditional bond theory for steel-OPC structures cannot be directly applied to FRP-AAC systems, making in-depth research on their bond mechanisms and influencing factors essential. This paper systematically summarizes the research progress in this field in terms of test methods, bond mechanisms, influencing factors, and theoretical models.

Common test methods for bond performance include the pull-out test, beam test, and half-beam test, among which the pull-out test is widely used because of its simplicity and ability to clearly present bond-slip curves. The bond resistance between FRP bars and AAC mainly comprises chemical adhesion, friction, and mechanical interlocking, and the force-transmission mechanism differs from that of steel-OPC due to the anisotropy and low shear strength of FRP-bar surfaces. The main failure modes include concrete splitting failure, FRP-bar splitting failure, and FRP-bar pull-out failure.

Key factors affecting bond performance include the following: 1) AAC properties. Compressive strength and porosity (especially the density of the interfacial transition zone, ITZ) strongly influence bond strength; higher compressive strength improves bond performance, while the transformation from N-A-S-H gel to C-A-S-H gel reduces ITZ porosity and improves bond stability. 2) FRP-bar characteristics. CFRP bars exhibit higher bond strength than BFRP and GFRP bars because of their higher elastic modulus and rougher surfaces; a smaller bar diameter and appropriate surface treatment contribute to better bond performance. 3) Bond length. Bond strength decreases with increasing bond length because of nonuniform stress distribution. 4) Durability. AAC provides better protection for FRP bars in high-temperature, high-salinity marine environments; CFRP bars have superior alkali resistance compared with GFRP and BFRP bars.

Existing bond strength prediction models are mainly developed for OPC systems and lack modifications that account for AAC characteristics, which leads to conservative predictions. For bond-slip constitutive modeling, the CMR model is more suitable for describing the ascending segment of bond-slip curves, whereas the descending and residual segments still require optimization.