The peer-reviewed data descriptor for this dataset has now been published in Elsevier Data in Brief - an open access journal aiming at enhancing data transparency and reusability, and can be accessed here: https://www.sciencedirect.com/science/article/pii/S2352340921008647. Please use the following citation when using the dataset: AlHamaydeh, Mohammad, and Amin, Fouad. "Strength Curve Data for Slender Geopolymer Concrete Columns with GFRP, Steel and Hybrid Reinforcement," Data in Brief, Vol. 39, December 2021, pp. 107589. DOI: 10.1016/j.dib.2021.107589. This dataset provides the normalized axial strength values for circular concrete columns under different loading conditions. Each file represents a group of columns with the same reinforcement type and strength. Within each file the axial strength values are provided for different reinforcement ratios and loading eccentricities. The provided data can be used for developing analytical strength curves for circular columns. Also, the axial load-bending moment interaction diagrams of the analyzed columns could be developed upon further processing of the provided data. Version v1: Assumes identical compressive and tensile strengths for the GFRP reinforcement. This assumption is made based on the lateral support provided by the concrete surrounding the reinforcement. Version v2: Assumes a more realistic assumption of the compressive strength being 80% of the tensile strength for the reinforcement. Selected supporting references: [1] ACI Committee 440. Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars, ACI 440.1R-15. vol. 88 Reappro. Farmington Hills, MI : American Concrete Institute: 2015. [2] Hadhood A, Mohamed HM, Benmokrane B. Flexural Stiffness of GFRP- and CFRP-RC Circular Members under Eccentric Loads Based on Experimental and Curvature Analysis. ACI Struct J 2018;115:1185–98. https://doi.org/10.14359/51702235.