改性竹原纤维水泥基复合材料制备及性能研究

发布时间：2018-04-11 18:17

本文选题：竹原纤维 + 水泥　；参考：《福建农林大学》2017年硕士论文

【摘要】：纤维增强水泥基复合材料可在一定程度上解决高性能水泥复合材料拉压比低、韧性差、耐久性低的问题。同时,纤维增强水泥复合材料也可提高水泥基材料的韧性,减少水泥基材料结构产生的荷载裂缝,克服早期收缩裂缝、易软化等缺点。本文采用竹原纤维为增强体,制备了竹原纤维增强水泥基复合材料。针对竹原纤维与水泥基体间界面相容性差的难题,采取三种价格低廉、方便简易的方法(甘油改性、铝酸酯改性和硅烷改性)对竹原纤维进行改性,对改性竹原纤维/水泥基复合材料进行核磁共振、扫描电镜、抗拉、抗压及干燥收缩、冻融破坏、碳化等实验,对复合材料的界面结合情况、孔隙率、抗拉强度、抗渗、抗冻融等性能进行研究。主要研究结果如下:(1)甘油改性竹原纤维增强水泥复合材料孔隙率最低,能显著提高复合材料的密实度。铝酸酯改性竹原纤维/水泥复合材料内部孔径分布比普通水泥复合材料更均匀,水分饱和后材料内部水分分布最均匀。(2)改性竹原纤维/水泥复合材料具有明显的多裂缝开裂特性和应变硬化,纤维改性显著提高了复合材料的韧性、抗拉强度和抗折强度。铝酸酯改性组折压比和拉压比相比标准组分别提高23%和61.4%(3)甘油改性竹原纤维/水泥复合材料有较好的力学性能及耐候性;试件破坏时具有较好的完整性,具有一定的塑性。(4)毛细吸水实验及氯离子侵蚀实验结果表明:改性竹原纤维的加入对抗渗性能影响较大,铝酸酯改性竹原纤维复合材料具有较好的抗渗性能。(5)干燥收缩、冻融破坏和碳化实验结果发现:甘油改性竹原纤维/水泥复合材料具有良好的抗收缩能力;铝酸酯改性竹原纤维/水泥复合材料抗冻能力优异,加入铝酸酯改性的竹原纤维能够有效地延缓水泥复合材料的老化进程,延长其使用寿命。
[Abstract]:Fiber reinforced cement matrix composites can solve the problems of low tensile / compression ratio, poor toughness and low durability of high performance cement composites to some extent.At the same time, fiber reinforced cement composites can also improve the toughness of cement-based materials, reduce the load cracks caused by the structure of cement-based materials, overcome the early shrinkage cracks, easy to soften and so on.In this paper, bamboo fiber reinforced cement matrix composites were prepared by using bamboo fibers as reinforcements.Aiming at the difficult problem of poor interfacial compatibility between bamboo fiber and cement matrix, three simple and convenient methods (glycerol modification, aluminate modification and silane modification) were adopted to modify bamboo raw fiber.The modified bamboo fiber / cement matrix composites were tested by NMR, SEM, tensile resistance, compression and drying shrinkage, freeze-thaw destruction, carbonization, etc. The interfacial bonding, porosity, tensile strength and impermeability of the composites were studied.The properties of freeze-thaw resistance were studied.The main results are as follows: 1) the porosity of glycerol modified bamboo fiber reinforced cement composites is the lowest and the compactness of the composites can be improved significantly.The pore size distribution of bamboo-fiber / cement composites modified by aluminate is more uniform than that of ordinary cement composites.The modified bamboo fiber / cement composites have obvious multi-crack cracking characteristics and strain hardening after water saturation. The fiber modification improves the toughness, tensile strength and flexural strength of the composites.Compared with the standard group, the flexural pressure ratio and tension compression ratio of aluminate modified group increased by 23% and 61.4% respectively) glycerol modified bamboo fiber / cement composite had better mechanical properties and weathering resistance, and the specimen had better integrity when it was destroyed.The results of capillary water absorption experiment and chloride ion erosion test showed that the addition of modified bamboo fiber had great influence on the permeability resistance, and aluminates modified bamboo fiber composite had better anti-seepage property.The results of freeze-thaw failure and carbonization test showed that glycerol modified bamboo fiber / cement composite had good anti-shrinkage ability, and aluminate modified bamboo fiber / cement composite had excellent freezing resistance.The bamboo-fiber modified by aluminate can effectively delay the aging process of cement composite and prolong its service life.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528.58;TB332

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