Experimental and Numerical Study of Nano-Modified Slag Concrete for Rigid Pavement Slabs with PP Fibers and GFRP Mesh under Repeated Impact

This study investigates sustainable rigid pavements using slag-based cement concrete enhanced with supplementary materials. Industrial slag, an eco-friendly and cost-effective by-product, partially replaced cement to improve strength, durability, and environmental performance. Thirteen concrete mixes were designed with varying slag contents (400–500 kg/m³) and fly ash replacement ratios (0–30%), along with nanomaterials (3% nano-silica, 10% silica fume, 3% metakaolin) and high-range water-reducing admixtures. Polypropylene fibers (1% by volume) were added to enhance crack resistance. Mechanical properties, including compressive, tensile, and flexural strengths, and durability indicators were evaluated. Results showed slag-based mixes outperformed conventional concrete, with nanomaterials and pozzolanic additives refining the microstructure, reducing porosity, and increasing flexural capacity.Rigid pavement slabs were tested under repeated impact loading using different reinforcement schemes. Slabs reinforced with Gavazzi glass fiber meshes, alone or combined with steel reinforcement, exhibited significantly higher impact resistance. The number of blows to first cracking increased from 2 in control slabs to 8 in reinforced ones, with minimal crack displacement (0.21 mm), and failure occurred after up to 70 blows, demonstrating high energy absorption. Numerical simulations using ABAQUS closely replicated experimental crack propagation, failure modes, and displacement, validating the model.Overall, integrating slag-based concrete with advanced nanomaterials and fiber reinforcement produces durable, high-performance, and sustainable pavements. Future work should explore long-term performance under varying service conditions.