Study on the Performance of Abrasion-resistance Concrete of Low Heat Cementitious for Ultra-high Dam

The discharge flow velocity in the spillway systems of ultra-high dams can reach 40–50 m/s, causing coupled damage of flow scouring and cavitation erosion on the surface of hydraulic structures. Therefore, high strength, high abrasion resistance, and low thermal cracking resistance in concrete are key requirement. This study employs low-heat Portland cement and systematically investigates the effects of different dosages and combinations of fly ash, silica fume, and a new admixture HDC on the mechanical properties, abrasion resistance, cavitation erosion resistance, and heat of hydration characteristics of concrete. The experimental results indicate that incorporating silica fume significantly enhances the mechanical properties and abrasion resistance of low-heat cement-fly ash system concrete, but reduces workability and increases the heat of hydration slightly. The additional addition of HDC further improves the mechanical properties, abrasion resistance, and cavitation erosion resistance of the concrete, while effectively suppressing the hydration heat. The composite mix with 20% FA + 2.5% SF + 2.5% HDC demonstrates the optimal performance, with Abrasion loss a 2.4% and cavitation loss 0.35%, respectively. Hydration heat tests show that adding 8% HDC could reduces the hydration heat by 9.4%, significantly improve the crack resistance. This study can provide an important reference for the material design and performance optimization of abrasion-resistant concrete for ultra-high dams.