Material mix and air content management of RCC at high elevation dam projects

Studies on the air content of RCC at projects located in high altitude areas of Tibet were undertaken using laboratory and field experiments to investigate the influence of strong sunlight, low atmospheric pressure, large daily temperature variations, and high rates of evaporation. Results show that with the same mix proportion, the air content of RCC at high-altitude is significantly less than that at lower altitudes. Mix proportions and quality control measures such as appropriately increasing the amount of air-entraining agent, controlling the appropriate ‘vibrating-compacted’ value at the mixing plant, and appropriate fine sand powder content are proposed.