超高掺量粉煤灰混凝土抗压强度和配合比设计的研究

发布时间：2018-11-16 14:20

【摘要】：粉煤灰作为发电厂的副产品一直污染着地球的环境,随着对粉煤灰的认识逐渐加深,人们将其运用到广阔的工程领域中,尤其是运用到混凝土工程之中。由于性能的优异性,混凝土是目前世界上运用最广泛的人工建筑材料,它的年产量(2012)现在已达到2亿吨,因此合理地开发和运用粉煤灰混凝土对于开发绿色建筑材料有着重要的意义。虽然目前对于粉煤灰混凝土的研究已经有了一定进展,但是对于高掺量粉煤灰混凝土的研究还有一定欠缺。对于一般粉煤灰混凝土而言,粉煤灰掺量为15%到20%之间,而高掺量粉煤灰混凝土的粉煤灰掺量也大都在50%左右,本文则围绕粉煤灰掺量为70%~90%的超高掺量粉煤灰混凝土展开研究。根据大连理工大学王立久教授提出的胶凝系数的概念,认为胶凝系数β是与粉煤灰细度、需水量和烧失量相关的变量,通过实验确定超高掺量粉煤灰混凝土的胶凝系数β的公式。从胶凝系数的角度,认为粉煤灰是超高掺量粉煤灰混凝土的单独组分,确定了与超高掺量粉煤灰混凝土配合比设计相关的三个参数:单位用水量、灰胶比、水胶比,以此为根据建立了超高掺量粉煤灰混凝土的配合比计算模型,根据大量的实验数据归纳了超高掺量粉煤灰混凝土的配合比设计步骤。最后,本文通过大量实验数据分析了粉煤灰的掺量、水胶比、粉煤灰激发剂的品种和养护龄期对其强度的影响,研究表明超高掺量粉煤灰混凝土的抗压强度会随着粉煤灰掺量的增加、水胶比的降低而降低,而且在标准条件下养护28d后抗压强度仍有所提高。针对粉煤灰自身的物理化学性质,在超高掺量粉煤灰混凝土中掺入一定的激发剂也可以相应提高其抗压强度。
[Abstract]:Fly ash, as a by-product of power plant, has been polluting the environment of the earth. With the deepening of the understanding of fly ash, people apply it to a wide range of engineering fields, especially to concrete engineering. Because of its excellent performance, concrete is currently the most widely used artificial building material in the world. Its annual output (2012) has now reached 200 million tons. Therefore, the reasonable development and application of fly ash concrete is of great significance to the development of green building materials. Although there has been some progress in the research of fly ash concrete, the research of high content fly ash concrete is still lacking. For the general fly ash concrete, the fly ash content is between 15% and 20%, and the fly ash content of the high content fly ash concrete is about 50%. In this paper, the fly ash concrete with 70% fly ash and 90% fly ash is studied. According to the concept of cementitious coefficient put forward by Professor Wang Lijiu of Dalian University of Technology, the cementitious coefficient 尾 is a variable related to the fineness of fly ash, water demand and burning loss. The formula of cementitious coefficient 尾 of super high content fly ash concrete is determined by experiment. From the point of view of cementitious coefficient, fly ash is considered as a separate component of ultra-high content fly ash concrete, and three parameters related to the mix design of ultra-high content fly ash concrete are determined: unit water consumption, ratio of cement to cement, ratio of water to binder, ratio of water to binder, Based on this model, the calculation model of mix ratio of ultra-high content fly ash concrete is established, and the design steps of mix ratio of super high content fly ash concrete are summarized according to a large number of experimental data. Finally, the influence of fly ash content, water-binder ratio, type of fly ash activator and curing age on its strength is analyzed through a large number of experimental data. The results show that the compressive strength of super-high content fly ash concrete will decrease with the increase of fly ash content and the decrease of water-binder ratio, and the compressive strength will still increase after 28 days of curing under standard conditions. According to the physical and chemical properties of fly ash itself, the compressive strength can be improved by adding certain activator in ultra-high content fly ash concrete.
【学位授予单位】：武汉轻工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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