Structural components are susceptible to different types of loading, such as monotonic and cyclic loadings, etc. Fatigue loading is cyclic in nature and falls into two general categories: low-cyclic fatigue and high-cyclic fatigue. Glass fibre-reinforced polymer (GFRP) bars are suitable replacements for steel reinforcement rebars due to their corrosion-resistant characteristics. This characteristic warrants an extended service life for GFRP RC structures. The research investigates the fatigue performance of ribbed GFRP bars in concrete, which is crucial due to the growing use of GFRP as a substitute for traditional steel reinforcements. An experimental program was carefully planned to evaluate the fatigue life of ribbed GFRP bars within concrete beams, including factors such as concrete strength and the degrees of fatigue stress applied. An innovative displacement-controlled testing technique was devised to address the limitations of conventional force-controlled fatigue testing methods. The results demonstrate that ribbed GFRP bars may withstand up to 2 million cycles of fatigue stress, exceeding current code standards and questioning previous empirical data. This research also includes the fatigue characteristics of ribbed GFRP bars during tension-tension fatigue through a detailed review and innovative experiments. The experimental program included the fatigue, the fatigue life and the behaviour of ribbed GFRP bars, classifying them according to the testing protocol. Low-frequency fatigue testing is between 0.03 and 0.04 Hz, and fatigue tests are under higher frequency fatigue testing at 4 Hz. This research identified an optimal gripping mechanism for conducting fatigue tests on GFRP bars and evaluated the feasibility of using conventional universal testing machines for fatigue life assessment, commonly found in many structural laboratories.  In addition, the impact of influential factors such as stress ratio is examined through a testing program. Finally, the study expands to present a simplified model based on the Sendeckyj model, but it utilizes a normal distribution to forecast the fatigue life of FRP-RC elements under repeated loading situations. This novel method is used to analyze fatigue data for GFRP, CFRP, and BFRP materials, allowing for the creation of S-N-P curves to be simplified with accurate estimations.