The effect of the type and content of multi-wall carbon nanotubes (MWCNTs) on the damping performance of cement mortar is studied in this paper. The pristine MWCNTs (P-CNT) and the functionalized MWCNTs (F-CNT) grafted with COOH were used in the experiment. The content of MWCNTs was 0.05wt% and 0.1wt% of cement. The flexural/compressive strength and loss factor of CNT-mortar composites were measured. The experimental results show that MWCNTs can significantly enhance the flexural strength and loss factor, and the values increased with the increase of CNTs content. The effect F-CNT was better than P-CNT when the MWCNTs content was the same due to the presence of COOH. The mechanism of MWCNTs reinforced mortar damping performance was analyzed by a variety of micro test techniques. The test results of X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and thermogravimetry showed that MWCNTs did not change the compositions of mortar, but improved the polymerization degree of gel and the degree of hydration of cement. The results of mercury intrusion porosimetry, N₂ adsorption and backscattered scanning electron microscopy showed that MWCNTs effectively reduced the porosity and interfacial transition zone thickness of mortar. Transmission electron microscope results showed that the energy dissipation capacity of mortar is increased due to the bridging effect of MWCNTs.

本文研究了多壁碳纳米管(MWCNTs)的种类和含量对水泥砂浆阻尼性能的影响。实验中使用了原始多壁碳纳米管 (P-CNT) 和接枝有 COOH 的功能化多壁碳纳米管 (F-CNT)。MWCNTs的含量为水泥的0.05wt%和0.1wt%。测量了 CNT-砂浆复合材料的弯曲/压缩强度和损耗因子。实验结果表明，多壁碳纳米管可以显着提高抗弯强度和损耗因子，并且随着碳纳米管含量的增加而增加。由于COOH的存在，当MWCNTs含量相同时，F-CNT的效果优于P-CNT。通过多种微观测试技术分析了MWCNTs增强砂浆阻尼性能的机理。X射线衍射测试结果，X射线光电子能谱、傅里叶变换红外光谱和热重分析表明，MWCNTs没有改变砂浆的组成，但提高了凝胶的聚合度和水泥的水化度。压汞孔隙率测定结果，N₂吸附和背散射扫描电镜表明，MWCNTs有效降低了砂浆的孔隙率和界面过渡区厚度。透射电镜结果表明，由于多壁碳纳米管的架桥效应，砂浆的能量耗散能力增加。