摘要
利用自行研制的活塞式挤压流变仪研究了掺加PVA短纤维和粉煤灰的地聚合物浆体在挤压过程中的流变学特性,在此基础上通过单轴挤压机成功制备出宽厚比为12.5的短纤维增强地聚合物基复合材料薄板。利用Rdm ana冲击试验机系统分析了各种纤维和粉煤灰掺量的地聚合物挤压板在冲击载荷作用下的力学响应行为。结果表明,PVA短纤维的加入改变了粉煤灰基地聚合物材料破坏模式:由脆性破坏变为延性破坏,使纤维的加入明显提高了粉煤灰基地聚合物材料的冲击韧性。对于不掺或掺加少量粉煤灰的地聚合物材料具有较高的冲击强度、刚度和韧性。当太多量的粉煤灰被加入后,粉煤灰基地聚合物复合材料薄板的抗冲击性能显著下降。通过扫描电镜(SEM)、X衍射(XRD)、激光粒度仪(LSA)等微观测试手段探讨了SFRGC的微观结构和冲击破坏机理。
The effect atically investigated s of fly ash and fiber on the rheological behaviors of geopolymeric pastes were systemby using the specially designed ram rheometer. Based on the rheological testing resuits, a PVA short fiber reinforced fly ash-geopolymer composites manufactured by extrusion technique (SFRFGC) was successfully prepared by adjusting the fiber volume fraction and fly ash content. The dymanic behaviors were then studied on the SFRFGC by using Rdmana impact tester. The experimental results show that for normally curing SFRGC, PVA fiber addition greatly increases the ductility of SFRGC, especially in the case of high volume fraction of fiber, resulting in a change of impact failure mode from brittle pattern to ductile one. As a result, a great increase in the impact toughness was seen in SFRGC with high fiber content. Comparatively fly ash addition also exhibits obvious influence on the rhelogical and impact behaviors. The spherical shape of fly ash particles can greatly improve the extrudability of fresh SFRGC pastes. SFRGC without or with low percentage of fly ash possesses very high impact strength and stiffness. However, when too much fly ash is incorporated, the impact resistance of SFRGC is reduced rapidly. The corresponding microstructure and failure mechanism are also explored by laser particle size analysis (LSA), X-ray diffraction analysis (XRD), and scanning electron microscope (SEM).
出处
《解放军理工大学学报(自然科学版)》
EI
2007年第6期599-605,共7页
Journal of PLA University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(50702014)
先进建筑材料四川省重点实验室开放课题基金资助项目(07XZJ01)
关键词
地聚合物
短纤维
粉煤灰
挤压
动态性能
微观结构
geopolymer
short fiber
fly ash
extrusion
rheological behavior
dynamic behavior
microstructure