不同粉磨工艺对粉煤灰性能的影响

发布时间：2018-07-14 17:24

【摘要】：本文系统研究不同粉磨工艺下粉磨的超细粉煤灰的基本性质差异以及将不同工艺粉磨的超细粉煤灰掺入混凝土中，对混凝土工作性能、力学性能和干缩性能的影响，主要得出以下结论： (1)用盘磨、环辊磨、振动磨和球磨四种不同粉磨工艺超细粉磨粉煤灰，，用盘磨粉磨的超细灰球形度最好，环辊磨次之，振动磨和球磨粉磨的超细灰球形度较差； (2)掺入超细粉煤灰可以显著改善混凝土的工作性能、力学性能和干缩性能，尤以用盘磨超细粉磨至3μm的超细灰最佳，其适宜掺入量为40%； (3)可以用超细粉煤灰代替硅灰配制高强混凝土，并有效解决因掺入硅灰而导致混凝土干缩性能变差的问题。与10%硅灰配制混凝土相比，用40%盘磨粉磨超细灰配制的混凝土，其拌合物坍落度较掺硅灰试样仅损失4%，28天抗压强度仅低1.53MPa，60天抗压强度仅低3.09MPa，而试样的干缩却减少了31.84%； (4)超细粉磨能够将复珠结构的粉煤灰原灰颗粒内部所包裹的更细小微珠释放出来，使更多细小颗粒充填在混凝土基体中，促进粉煤灰在混凝土中的水化反应，从而更充分发挥粉煤灰颗粒的形态效应、微集料效应和火山灰效应。
[Abstract]:In this paper, the basic property difference of ultrafine fly ash grinding under different grinding processes is studied systematically, and the influence of superfine fly ash from different grinding processes on the working performance, mechanical properties and dry shrinkage property of concrete is also studied. The main conclusions are as follows: (1) the ultrafine fly ash is ground by disc mill, ring roller mill, vibration mill and ball mill, the ball mill is the best, and the ring roller mill is the second. The spherical degree of ultrafine fly ash in vibration mill and ball mill is poor. (2) the addition of ultrafine fly ash can significantly improve the working performance, mechanical properties and dry shrinkage performance of concrete, especially the ultrafine fly ash, which is ground to 3 渭 m by disk mill. (3) superfine fly ash can be used instead of silica fume to prepare high strength concrete, and the problem of poor shrinkage property of concrete caused by adding silica fume can be effectively solved. Compared with the concrete prepared with 10% silica fume, the slump of the concrete prepared with 40% disc grinding ultrafine ash only lost 4 ~ 28 days and the compressive strength of 60 days was only 3.09 MPA, while the dry shrinkage of the sample was 31.84. (4) ultrafine grinding can release more fine particles from the inner particles of fly ash primary fly ash, and make more fine particles fill in the concrete matrix, thus promoting the hydration reaction of fly ash in concrete. Thus, the morphology effect, micro-aggregate effect and pozzolanic effect of fly ash particles can be brought into full play.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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