多壁碳纳米管对水泥基建筑材料力学性能和微观结构的影响研究

Effect of Multi-walled Carbon Nanotubes on Mechanical Properties and Microstructure of Cement-based Building Materials

为了研究多壁碳纳米管(MWCNTS)含量、水灰比和加入方式对水泥基建筑材料力学性能和微观结构的影响,在水灰比分别为0.25、0.3、0.35和0.4时,制备了MWCNTs含量为0%0.05%、0.08%、0.10%0.15%、0.20%和0.30%的试件。测试了材料的物理性能、力学性能和显微组织结构。试验结果表明:随着MWCNTS含量和水灰比的增加,水泥基建筑材料的抗弯强度和抗压强度先增大后减小,在MWCNTs含量为0.1%,水灰比为0.3时,复合材料的抗弯强度和抗压强度达到最大,超声处理有利于增加复合材料的机械强度;SEM测试表明,水泥基体被MWCNTs紧密包裹,使得MWCNTS在内部孔隙中起到良好的桥接和填充作用,增强了水泥基体的密实度,有效抑制了微裂缝的发展,从而显著提高了机械强度。

In order to study the effects of multi-walled carbon nanotubes(MWCNTs)content,water-cement ratio and addition method on the mechanical properties and microstructure of cement-based building materials,when the water-cement ratio is 0.25,0.3,0.35 and 0.4 respectively,the samples containing 0%,0.05%,0.08%,0.10%,0.15%,0.20%and 0.30%MWCNTs are prepared.The physical properties,mechanical properties and microstructure of the material are tested.The test results show that with the increase of MWCNTs content and water-cement ratio,the flexural strength and compressive strength of cement-based building materials first increase and then decrease.When the MWCNTs content is 0.1%and the water-cement ratio is O.3,the flexural strength and compressive strength of the composite materials reach the maximum.Ultrasonic treatment is beneficial to improving the mechanical strength of the composite materials.SEM tests show that thecement matrix istightly wrapped byMWCNTs,which makes the MWCNTs play a good bridging and filling role in the internal pores,and enhances the compactness of the cement matrix,effectively inhibits the development of micro-cracks,and significantly improves the mechanical strength.