碳纳米管增强水泥砂浆梁弯曲性能试验研究

Experimental study about flexural property of carbon-nanotube reinforced cement mortar beam

以水泥砂浆为基体,多壁碳纳米管(MWCNT)为增强组分,采用不同的分散剂和分散方法制备碳纳米管水泥砂浆(MWCNTRM)。通过对碳纳米管水泥砂浆标准试件的三点弯曲试验,研究了分散剂类型及其掺量、水灰比、碳纳米管掺加量对碳纳米管水泥砂浆梁弯曲性能的影响。结果表明:分散剂与碳纳米管的质量比存在一个临界值(分散剂为CTAB时约为3.0,分散剂为PVP时约为4.0),当分散剂掺加量大于或小于此值时,所得碳纳米管水泥砂浆梁的挠曲强度均有不同程度的减小;碳纳米管掺加量存在一个最优值,当掺量大于或小于此值时,其增强效果减弱;随着水灰比的增加,碳纳米管水泥砂浆梁的挠曲强度反而有所提高,其相应砂浆的流动性要比相同水灰比的素水泥砂浆的流动性要差。

In this article, fiber-reinforced Cement Mortar with multi-walled carbon nanotubes （MWCNTs） loadings were fabricated with different surfactant and dispersion method.It is shown that for effective dispersion the application of ultrasonic energy is absolutely required.The flexu- ral behaviour of reinforced cement mortar beams with different surfactant and concentration, water cement ratio, concentration of MWCNTs were investigated by three point bending test.Results show that there exists an optimum weight ratio of surfactant to MWCNTs （about 3.0 to CTAB, about 4.0 to PVP）.When the concentration of surfactant is higher or lower, the reinforcing effect is decreased.There also exist a best quantity of mixing amount of MWCNTs,the flexural strength reached its maximum when using this dosage of MWCNTs.Results suggest that the flexural strength of the carbon-nanotube reinforced cement mortar beams increased with water-cement ratio increasing.Comparing to plain cement mortar, the fluidity of MWCNTs-reinforced cement mortar decreases to some extent.