煤矸石加气混凝土的性能研究

发布时间：2018-03-31 21:51

  本文选题：煤矸石　切入点：加气混凝土　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：伴随煤矿产业而生的煤矸石已成为我国现有排放量最大的固体废弃物,由于煤矸石山的堆放引发了环境和社会方面的诸多问题。近年来,许多国家为了高效地解决煤矸石堆放引发的环境问题,把大量的煤矸石应用于建筑产业,得到了良好的效果。目前,加气混凝土产业在我国蓬勃发展。利用煤矸石制备加气混凝土砌块对于我国的环境资源、社会资源和科学研究领域都具有重要的意义。通过采用四因素三水平的正交试验,得到了试验范围内煤矸石加气混凝土基体材料的最佳配合比为煤矸石:生石灰:水泥:石膏=60:18.5:18.5:3,此时基体材料抗压强度可达20.9MPa。加气混凝土料浆中的气泡通过在浆体中上浮来促使浆体体积膨胀,氢气泡的半径r越大,且竖直方向的气泡之间距离h越小时,更有利于实现单位质量加气混凝土料浆的体积增大。聚羧酸高性能减水剂能够引起煤矸石加气混凝土浆体的异常稠化,不适宜用来调节煤矸石加气混凝土浆体的扩展度。在煤矸石加气混凝土基体材料最佳配合比的基础上,采用三因素三水平的正交试验对元素的钙硅比C/S和铝粉的最优掺量进行了确定,综合考虑力学性能与物理性能,确定了煤矸石加气混凝土的实验室最优配合比为煤矸石:生石灰:水泥:石膏=54:23:20:3,铝粉掺量为基体材料总量的1.3‰,水灰比为0.5,此时基体材料的钙硅比为0.82。实验室确定的煤矸石加气混凝土的养护制度为:在1.1MPa的真空压力下恒温187℃养护8h。XRD测试结果表明该蒸压养护制度能够使得大量煤矸石加气混凝土的基体材料生成托勃莫来石型CSH水化产物。研究表明,煤矸石加气混凝土中的孔主要介于0.5mm~2mm之间,并存在一定数量的连通孔。50次冻融循环使得煤矸石加气混凝土试块的质量有所增加,为裂缝吸水和胶凝材料继续水化的共同作用。硬脂酸钙的加入能够有效抑制加气混凝土试块早期的材料吸水,但会使抗压强度显著下降,对抗冻性能不利。稳泡剂对提高煤矸石加气混凝土的抗冻性能有利,使得50次冻融循环后试块的抗压强度显著增加,扩展度为250mm、290mm和320mm的试块抗压强度增加程度分别达到了15.5%、26.5%和30.4%。
[Abstract]:Coal gangue produced by coal mine industry has become the largest emission of solid waste in China. Because of coal gangue mountain stacking caused many environmental and social problems in recent years, In order to efficiently solve the environmental problems caused by coal gangue stacking, many countries have applied a large number of coal gangue to the construction industry and got good results. The aerated concrete industry is booming in China. The preparation of aerated concrete blocks from coal gangue is of great significance to our country's environmental resources, social resources and scientific research fields. The optimum mix ratio of coal gangue aerated concrete matrix material was obtained as follows: coal gangue: quicklime: cement: gypsum 60: 18.5: 18.5: 3. The compressive strength of the matrix material can reach 20.9 MPA. The bubble in aerated concrete slurry passes through the slurry. To inflate the volume of the slurry, The larger the radius of hydrogen bubble is, the smaller the distance between the vertical bubbles is. Polycarboxylic acid high performance water reducing agent can cause abnormal thickening of coal gangue aerated concrete slurry. It is not suitable for regulating the expansion of coal gangue aerated concrete slurry. On the basis of the optimum mix ratio of coal gangue aerated concrete matrix material, Three factors and three levels of orthogonal test were used to determine the optimum content of C- / Si ratio and aluminum powder, and the mechanical and physical properties were considered synthetically. The optimum mix ratio of coal gangue aerated concrete in laboratory is determined as coal gangue: quicklime: cement: gypsum 54: 23: 20: 3, and the amount of aluminum powder is 1.3 鈥，

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