Abstract: Harsh environments pose an adverse effect on the interlayer bonding properties of extra-high arch dams. In this study, interlayer splitting tensile strength of dam concrete is tested experimentally at different temperatures, and a relationship between maturity and strength coefficient is established. And we develop a three-level nine-gradient early warning system for dam interlayer properties based on the relationship between maturity, strength coefficient and water content, taking maturity as the main factor and water content as a supplement. The results show that for the dam concrete tested, its interlayer mechanical performance degrades with a rise in temperature, and its maturity is linearly related to its strength coefficient and water content, with correlation coefficients of 0.9985 and 0.9964 respectively. And by using this early warning system based on the relationship between maturity and interlayer properties parameters, an effective control of dam interlayer bonding quality can be realized.

Key words: extra-high arch dam, interlayer properties, water content, maturity, early warning system