表面活性剂对超高分子量聚乙烯UPE纤维分散性及其砂浆力学性能的影响

Effect of surfactant on the performance of the UHMWPE fiberdispersionand its cement mortar

分别采用硅烷偶联剂KH570、聚乙烯醇和羟丙基纤维素三种表面活性剂处理超高分子量聚乙烯UPE纤维,研究了处理后纤维在水泥基中的分散性能及其砂浆的力学性能的影响。结果表明:与处理前纤维相比,经处理后的纤维,可明显提高纤维的亲水性能。一定范围内,纤维在砂浆中的分散性相对误差越小砂浆抗折强度越高,当分散误差低于7%时,抗折强度趋于稳定。与7 d龄期的素砂浆相比,较低掺量下,除硅烷偶联剂KH570能降低砂浆强度外,其余两者基本不会对砂浆强度造成影响。与处理前7 d龄期的纤维砂浆相比,经硅烷偶联剂KH570处理后的纤维砂浆的抗折、抗压强度分别降低17.1%、15.3%,弯曲韧性指数I5、I10、I30分别提高了9.7%、19.5%、14.1%;经聚乙烯醇、羟丙基纤维素处理后的纤维砂浆抗折强度分别提高7.7%、8.1%,弯曲韧性指数I5、I10、I30分别提高了8.0%、10.4%、11.6%、13.3%、13.4%、19.6%,抗压强度变化不大。

It was conducted on the different effects of coupling agent,PVA and HPMC on the performance of the UHMWPE fiber and its cement mortar.Experimental results indicated that the hydrophilic property of the modified fiber was superior to the unmodified fiber , andwithin a certain range,the fiber dispersion in the mortar was positively correlated with its flexural strength.When the dispersion error was less than 7%,the flexural strength tended to be stable.Compared to plain cement mortar at 7 ages ,PVA and HPMC basic will not af-fect the mechanical properties of mortar,while the silane coupling agent KH570 can reduce the strength of mortar.Compared to unmodified fiber mortar at 7 ages,the flexural,compressive strengths of silane coupling agent KH570 modified fiber mortar decrease by 17.1%,15.3%respectively,and the bending toughness indexes of I5,I10,I30 increase by 9.7%,19.5%,14.1% respectively.And the flexural strengths of PVA and HPMC modified fiber mortar decrease by 7.7%and 8.1%respectively ,and the bending toughness indexes of I5,I10,I30 increase by 8.0%,10.4%,11.6%and 13.3%,13.4%,19.6%respectively,while the compressive strength change is not obvious.