一种多壁羧基化碳纳米管改性水泥砂浆的抗压强度研究

Study on compressive strength of cement mortar modified with multi-walled carboxylated carbon nanotubes(CNT-COOH)

研究了一种多壁羧基碳纳米管(CNT-COOH)对水泥砂浆抗压强度的影响。为了得到均匀的悬浮液,将CNT-COOH分散在蒸馏水中,然后对其进行超声波处理;进而将CNT-COOH按水泥质量的0.01%、0.05%、0.10%质量比制备水泥砂浆样品。结果表明:随着CNT-COOH含量从0.01%增加至0.10%,砂浆7 d龄期抗压强度增长幅度从14.9%提升至44.8%,28 d龄期抗压强度增长幅度从5.3%提升至22.4%;而且,随CNT-COOH掺量增加,砂浆7 d龄期与28 d龄期抗压强度的比值增加,CNT-COOH掺量为0.10%的水泥砂浆的7 d抗压强度达到28 d抗压强度的76.8%;SEM图像表明,CNT-COOH有效的发挥了填充和裂缝桥接效应,而且成核效应突出,其中的含氧官能团可以参与并促进水化反应。

The effect of multi-walled carbon nanotubes(CNT-COOH)on compressive strength of cement mortar was studied.In order to obtain a uniform suspension,CNT-COOH was well-dispersed in distilled water and then treated by ultrasonic.The cement mortar specimens were prepared via mixing CNT-COOH of 0.01%,0.05%and 0.10%of cement weight respectively.The results show that with the increasing of CNT-COOH content from 0.01%to 0.10%,the compressive strength of mortar increases from 5.3%to 22.4%at 28 d age,and dramatically from 14.9%to 44.8%at 7 d age.Meanwhile,the ratio of compressive strength at 7 d and 28 d ages of mortar increases with the increase of CNT-COOH content,and reached 76.8%at 0.10%content of CNT-COOH.The SEM images show that CNT-COOH can effectively play the filling and fracture bridging effect,and the nucleation effect is prominent,in which the oxygen-containing functional groups can participate in and promote the hydration reaction.