Low carbon and high performance have become key trends in the development of construction materials. Understanding the mechanism by which curing conditions affect the mechanical properties of high-ductility geopolymer concrete (HDGC) is of significant importance. This study investigated three sealing curing temperatures (room temperature, 45 °C, and 60 °C) and four curing durations (1 day, 3 days, 5 days, and 7 days), while considering two final curing ages (7 days and 28 days) to explore their effects on the axial tensile and compressive properties of HDGC. The results showed that both 45 °C and 60 °C could improve the brittle failure of HDGC under axial compressive loading. However, curing at 60 °C and for durations longer than 1 day in an oven would catalyze the formation of eight-faced zeolite crystals within the slag–fly ash geopolymer matrix, and it could weaken the matrix’s pore structure and subsequently affect the material’s later strength development. Nevertheless, oven heat curing enhanced the bridging effect between the fibers and the matrix, partially compensating for the reduction in the initial tensile strength of HDGC. This follows the pseudo-strain-hardening material’s saturation cracking criterion to enhance the strain-hardening behavior of HDGC and improve its tensile energy absorption capacity. A curing condition of 45 °C for 5 days is recommended to maximize the ductility of HDGC. This study provides important theoretical support for the design and promotion of green, low-carbon, high-ductility composite materials.

This study introduces the Quick Group Search Optimizer with Passive Congregation (QGSOPC) coupled with the influence-matrix method to optimize cable forces in a completed 1 070 m, five-span, twin-tower cable-stayed bridge. Compared with the original design, QGSOPC reduces maximum tower-top displacement by 83.8% (84.1 → 13.6 mm), girder deflection by 41.9% (236.7 → 137.5 mm) and peak bending moment by 11% (118 078 → 105 120 kN·m), while lowering the composite objective function by 40.7%. A comparative analysis using GSO confirms the enhanced performance of the proposed algorithm. The results demonstrate that QGSOPC offers a practical, efficient tool for achieving the "straight-tower & level-beam" completion state of long-span cable-stayed bridges.