摘要
以聚丙烯纤维为对比研究了新型材料玄武岩纤维(BF)对水泥砂浆的抗压、抗折强度和干缩的影响,并采用XRD、SEM及MIP现代检测技术对纤维微观作用机理进行了分析。结果表明:玄武岩连续纤维具有替代聚丙烯纤维的可行性;BF的加入提高了水泥砂浆的早期强度,但使28d强度有所降低;对早期砂浆的收缩有明显的改善效果,但28d以后对砂浆收缩的影响作用不显著;微观分析显示早期水化浆体中由于纤维-水泥石界面结合紧密和纤维乱向作用阻止了裂缝的引发与扩展,提高了水泥基材料早期力学性能。28d掺加纤维的水泥浆体在纤维-水泥石界面上产生弱界面,界面的弱化与总空隙率增加的共同作用导致掺加纤维水泥砂浆的长期力学性能下降。
Compared with the polypropylene fibers, the effects of new basalt fibers（BF） on the compressive and flexural strength and shrinkage of the composites were studied. And the influence of adding fibers on hydrated pastes microstructure is probed by applying to XRD, SEM, MIP testing means in this paper. The results indicate that BF has potential possible for replacing PP in cement composite. The addition of BF fiber into cement mortar has a greater compressive and flexural strength than blank at early hydration period, but decreases the strength of cement mortar at 28d. The dry shrinkage can be decreased especially at early-age shrinkage, but the effect of decreasing shrinkage is not distinctness after 28d. Adding Fibers on cement mortar can decrease the water loss on the surface of cement mortar, as a result, the dry shrinkage can be decreased. Microstructure analysis shows the fiber-cement interface has a better bonding state, At the same time, Fibers in the cement mortar have a random-oriented supporting system, the mechanics performance has a more increase than blank at 3d. At 28d, the material adding fiber into cement paste has a feeble fibe^cement interface, and the MIP shows that with adding fibers at 28d increase the ratio of porosity and pore diameter of cement paste, these factor lead to a decreasing the mechanics performance at a long term.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2008年第5期765-769,共5页
Journal of Materials Science and Engineering
基金
河海大学创新基金资助项目(2013406087)
关键词
武岩纤维
水泥砂浆
物理力学性能
微观结构
basalt fiber
mortar
physical and mechanical properties
microstructure
