Impact of Polyvinyl Alcohol Fibers and Nano‐Silica on the Mechanical and Durability Properties of Geopolymer Mortar for Improved Performance in Harsh Environments

ABSTRACT Concrete remains the most widely utilized construction material because of its strength, durability, and affordability. However, geopolymers are emerging as a sustainable alternative with the potential to replace conventional concrete. This study explores the mechanical and durability properties (DP) of geopolymer mortar synthesized from fly ash (FA) and metakaolin (MK) modified with nano‐silica (SiO 2 ) and polyvinyl alcohol (PVA) fibers. The primary objective is to enhance compressive strength (CS) and fracture performance through an optimized mix design and predictive modeling. The Finite Element Interpolated Neural Network (FEINN) model was developed to predict fracture characteristics of the geopolymer mortar. Results revealed that the optimal mix containing 0.8% PVA and 1% nano‐SiO 2 achieved 63.8 MPa compressive strength, 10 MPa flexural strength (FS), 51 MPa residual strength, 4.1 kN peak load, 70 mm critical crack length, and 0.61 MPa·m 1 / 2 fracture toughness, though with a 26.4% reduction in workability. The FEINN model, implemented in MATLAB, demonstrated superior prediction performance with 99.5% accuracy, RMSE of 0.05, MAE of 0.06, and an R 2 value of 0.95, outperforming existing methods like long short‐term memory (LSTM), deep neural network (DNN), and artificial neural network (ANN).