Finite element investigation of geopolymer hollow-core slabs for sustainable structural applications

The self-weight of a structure has a significant influence on both cost and structural performance; therefore, its reduction remains a key design objective. Since concrete slabs are among the heaviest structural elements, the adoption of hollow-core systems provides an efficient solution for reducing self-weight without a significant loss in load-carrying capacity. When combined with geopolymer concrete, these systems further reduce self-weight and material consumption while enhancing sustainability through lower energy demand and reduced environmental impact. In the present study, a finite element investigation was conducted using ANSYS to evaluate the influence of key parameters on the load-carrying behavior of geopolymer concrete hollow-core slabs. These parameters include the shear span-to-effective depth ratio (a/d), core size, core shape, and reinforcement ratio. Experimental results were used to calibrate the adopted geopolymer concrete material model. The calibrated Menétrey-Willam constitutive model showed strong agreement with the experimental compressive and flexural responses, confirming its suitability for simulating the nonlinear behavior of geopolymer concrete structural elements. The results indicate that geopolymer hollow-core slabs can effectively reduce self-weight without a significant reduction in load-carrying capacity. The solid slab exhibited the highest stiffness and ultimate load, whereas the circular-void configuration achieved the most efficient balance between structural strength and self-weight reduction.