Abstract: Through the indoor test, the dynamic elastic modulus of concrete was measured by using impact elastic wave method. The effect of rubber powder and its content on frost resistance durability of concrete was researched by experiment. The results show that, compared with ordinary concrete, when the number of freeze-thaw times is less, adding appropriate amount of rubber powder will cause the quality of concrete to increase, the dynamic elastic modulus to decrease, the relative dynamic elastic modulus to increase and the compressive strength to decrease; so the content of rubber powder has little effect on the frost resistance of concrete. However, when the number of freeze-thaw times is more, adding appropriate amount of rubber powder will cause the mass loss ratio of concrete to decrease, the dynamic elastic modulus, relative dynamic elastic modulus and the compressive strength of concrete to increase; so the frost resistance of concrete is enhanced, and the optimal mixing amount of rubber powder for concrete is 15~20 kg/m3. Finally, the micro-mechanism of enhancing the frost-resistance durability of concrete by mixing rubber powder was researched through SEM test. The research results can provide theoretical basis and reference for the design of concrete frost resistance durability.

Key words: hydraulic engineering, concrete, rubber powder, frost-resistance durability, impact elastic wave, mass loss, dynamic elastic modulus, compressive strength

摘要： 通过室内试验，采用冲击弹性波技术测量混凝土的动弹模，研究了橡胶粉及掺量对混凝土抗冻耐久性的影响。结果表明：与普通混凝土相比，冻融次数较少时，适量掺加橡胶粉，混凝土的质量增加、动弹模降低、相对动弹模增加、抗压强度有所降低，橡胶粉掺量对抗冻性能影响不大；但冻融次数较大时，适量掺加橡胶粉，混凝土的质量损失率减小，动弹模、相对动弹模及抗压强度增加，抗冻性能增强，最佳橡胶粉掺量为15~20 kg/m3。通过扫描电镜试验分析，揭示了掺加橡胶粉提高混凝土抗冻耐久性的微观机理。研究成果可为混凝土抗冻耐久性设计提供理论依据和参考。

关键词: 水利工程, 混凝土, 橡胶粉, 抗冻耐久性, 冲击弹性波, 质量损失, 动弹模, 抗压强度