中文摘要：

通过碳纤维在新拌水泥浆体中的变动系数、硬化水泥浆体电阻率和SEM分析测试等综合评价了羟丙基甲基纤维素（HPMC）对碳纤维在水泥浆体中的分散性的影响。试验发现：HPMC能显著改善纤维的分散,掺量在0.2%～0.4%时,分散效果较好。分析认为机理在于其分子结构中的极性羟基基团与碳纤维表面的极性羟基基团或羰基基团以及水分子之间形成氢键,增强了短碳纤维表面的亲水性和浸润性,提高了短碳纤维的分散性;但掺量较大反而由于体系粘聚性增加而影响分散性,且由于引入较多气泡而使电阻率提高。

英文摘要：

With the tests of the variation coefficient of fresh cement paste,the conductivity of hardened cement paste,and the scanning electron microscope（SEM）,the effects of HPMC on the dispersibility of carbon fiber in cement paste were evaluated.The results of the tests show that the adding of HPMC can significantly improve the fiber dispersibility.In the range of 0.2%-0.4% adding of HPMC,the dispersibility of carbon fiber is the best.The mechanism of the positive effect of HPMC on the dispersibility of carbon fiber is that hydrogen bonds are formed among the polar hydroxide radicals in its molecule structure and on the surface of the carbon fiber,and the water.Therefore the hydrophilicity and the wetting ability of the surface of carbon fiber can be increased,and then its dispersibility is improved.However,at higher admixture content,HPMC may increase the cohesiveness of the system and induce negative effect on the dispersibility,also it may increase the porosity and affect the conductivity.