亚微级纤维素纤维对水泥浆体微观结构的影响

以H_2SO_4溶液酸解脱脂棉的方法制备亚微级纤维素纤维(SCF),研究了其对水泥浆体微观结构的影响.结果表明:原始脱脂棉在酸解作用下,微原纤逐步剥离,形成尺度细小的亚微级纤维素纤维,且其直径随着H_2SO_4溶液质量分数的增大、酸解时间的延长而逐渐减小;亚微级纤维素纤维与水泥浆体具有很好的相容性,水泥水化产物依附于亚微级纤维素纤维表面生长;由于亚微级纤维素纤维在尺度上与C-S-H凝胶相匹配,因此随着水泥水化产物的不断生成、生长,该纤维逐渐被其包埋,从而起到诱导和桥接作用,使水泥浆体的微观结构更加均匀.

Effect of Submicron Cellulosic Fiber on the Micro structure of Cement Paste

The submicron cellulosic fiber(SCF) was prepared by acid splitting cotton fiber in H2SO4 solution. Laser particle size analyzer, scanning electron microscopy(SEM) and FTIR spectrometer were used to evaluate the diameter, structure and composition of the SCF. It is found that the natural cellulosic fiber split into more fine fiber, with a diameter range from dozens of micron to hundreds of nanometers, decreasing with the increasing sulfuric acid concentration or prolonging reaction time. Then the effect of SCF on the micro structure of cement paste was investigated by SEM and FTIR. The test results indicate that the compatibility of cellulosic fiber and cement paste is well, the hydration product C S H gel grows on and along the surface of SCF and finally embed it inside. The induction and bridging effect of SCF make the microstructure of cement paste more homogeneous.