PURPOSE: A mixture having stable strength, improved high-temperature properties and brittleness resistance at low temperature free from reduction in strength by water immersion, obained by dispersing red mud into hot asphalt by a flashing method consisting of a fatty oil and an alkylamide, followed by blending the dispersion with sand and crushed stone.

CONSTITUTION: Red mud is dispersed into hot asphalt by a flashing method consisting of a fatty oil and an alkylamide to give a dispersion, which is blended with sand and crushed stone. The alkylamide has preferably a boiling point of 120W220°C(3mmHg), a freezing point of -8W16°C, a specific gravity of 0.87W 0.88(25°C), a viscosity of 13W19(25°C, cps), and water-solubility of 8W38 (25°C, g in 100g).