Abstract: The Baihetan dam was built of low-heat cement concrete. To understand its properties under the condition of dry curing, this study focuses on the development of its compressive strength and splitting tensile strength, and presents an analysis on the features of microscopic morphology and pore structure obtained using scanning electron microscope and mercury intrusion methods. Results show that under dry curing, 33.3% of the 28d compressive strength and 31.6% of the splitting tensile strength are lost relative to the standard curing. And dry curing leads to a smaller quantity of hydration products, a significant increase in concrete porosity and pore volume, a decrease in the total area of pores, and the dominance by macropores in a size range of 100 nm to 1000 nm. Thus, this study has verified that dry curing has an adverse effect on the development of microstructure and strength of low-heat cement dam concrete.

Key words: low-heat cement, concrete, dry curing, strength, pore structure, mercury intrusion