Abstract: Radial splitting tensile tests for natural and water saturated concrete specimens with size of Φ150×150mm was carried out under different strain rates(10^-5,10^-4,10^-3 and 10^-2s^-1). Splitting tensile strength of concrete was analyzed in detail, and energy release characteristics and damage law of natural and water saturated concretes were researched in the whole process of splitting tensile damage by real-time acoustic emission data. The results show that: 1) with the increase of loading rate ,splitting tensile strength of natural and water saturated concretes increases; 2) at low strain rates (10^-5,10^-4 and 10^-3/s), the splitting tensile strength of water saturated concrete is smaller than that of natural concrete due to the wedging action of free water, whereas at the strain rate of 10^-2/s, the splitting tensile strength of water saturated concrete is larger than that of natural concrete due to Stefan effect; 3) dynamic enhancement factor of water saturated concrete is larger than that of natural concrete, and strain rate sensitivity of water saturated concrete is more obvious; 4) acoustic emission signal characteristics is in accordance with concrete failure characteristics, and acoustic emission data can be used to accurately monitor the process of concrete splitting tensile failure.

Key words: concrete, water saturated, strain rate, dynamic splitting tensile characteristics, acoustic emission