疏浚底泥制备免烧砖的结构与性能研究

发布时间：2018-01-07 00:03

本文关键词：疏浚底泥制备免烧砖的结构与性能研究　出处：《天津科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国疏浚行业每年产生大量的疏浚底泥,疏浚底泥废弃物占地面积广,易造成二次污染,急需处理,近年来有关疏浚底泥资源化利用的研究备受关注。本文致力于探索研究将疏浚底泥用于制备免烧砖,本课题不仅能有效解决疏浚底泥处理难题,符合国家政策导向,同时可以节能利废,保护我国土地资源。目前,疏浚底泥制备免烧砖现有的工艺为疏浚底泥直接与胶凝材料混合搅拌,经压制成型、养护(蒸养、蒸压、自然养护)等步骤制成免烧砖,但所制免烧砖存在最大的问题是强度低、易水化、综合耐久性差。本文在系统分析疏浚底泥理化性质的基础上,研究了免烧砖的强度成型机理,首次提出疏浚底泥免烧陶粒制备免烧砖工艺,测试并分析了疏浚底泥免烧陶粒对免烧砖结构与性能的影响及机理。具体研究内容及结果如下:(1)研究了疏浚底泥制备免烧陶粒的工艺及最佳原料配比。以疏浚底泥不同初始含水率为原料,确定了两种疏浚底泥制备免烧陶粒可行性工艺。疏浚底泥制备免烧陶粒原料最佳配比为绝干疏浚底泥80%、水泥3%、生石灰3%、石膏3%、粉煤灰5%、水玻璃6%。结合粒径分布、筒压强度、堆积密度和吸水率测定表征疏浚底泥免烧陶粒性能,通过XRD、TG/DTG、SEM分析疏浚底泥免烧陶粒微观结构。(2)研究了疏浚底泥制备免烧砖的可行性工艺。疏浚底泥直接掺入法所制免烧砖强度低、极易水化。疏浚底泥免烧陶粒制备免烧砖工艺所制免烧砖强度大幅度提升,耐水性及综合耐久性良好,为疏浚底泥制备免烧砖可行性工艺。(3)探索了疏浚底泥免烧陶粒制备免烧砖最佳原料配比。通过正交试验确定陶粒、水泥、复合胶凝材料掺量及陶粒颗粒级配对免烧砖强度影响关系,得出原料最佳配比为免烧陶粒54.17%、水泥12.5%、粉煤灰24.38%、生石灰6.97%、石膏1.99%。陶粒最佳颗粒级配为L1:5mm,67%;5-8mm,33%。(4)研究了疏浚底泥免烧陶粒对免烧砖结构与性能的影响及机理。以粉煤灰免烧砖作对比,结合抗压和抗折强度、接触角、吸水率、密度、抗盐冻、耐酸碱腐蚀的测定表征了疏浚底泥免烧陶粒对免烧砖性能的影响,通过XRD、TG/DTG、SEM分析了陶粒免烧砖微观结构。结果表明:陶粒免烧砖抗盐冻、耐酸碱腐蚀性好,表现出良好的综合耐久性,但需避免在低浓度盐溶液环境中使用。陶粒免烧砖与粉煤灰免烧砖强度相近,表面均具有疏水性,耐水性好,微观结构相似,且陶粒免烧砖质轻,内部结构更为致密,内部物料水化作用更充分。
[Abstract]:A large number of dredged sediment produced every year in China dredging industry, dredging waste covers an area wide, easy to cause two pollution, urgent treatment, in recent years research on dredged sludge resource utilization has attracted much attention. This paper is devoted to the exploration of the dredged sediment for preparation of brick, this paper not only can effectively solve the dredged sludge treatment the problem, in line with national policy guidance, and energy saving and waste, protection of land resources in our country. At present, dredging preparation of brick existing technology for dredged sediment directly with the cementitious material by mixing, compression molding, curing (steamed, autoclaved, natural curing) and other steps made of unburned brick, but the brick are the biggest problem is the low strength, hydration, comprehensive poor durability. Based on the systematic analysis of dredged sediment on the physical and chemical properties, mechanism of strength forming brick, thinning is put forward for the first time Sediment dredging unburned ceramisite preparation of brick process, test and analysis of dredged sediment unburned ceramisite effects on structure and properties of unburned brick and mechanism. The specific research contents and results are as follows: (1) the process of dredging preparation of unbaked ceramsite and optimum feedstock ratio. With different initial water content of dredged sediment as raw materials. Two kinds of dredged sediment preparation process was determined. The feasibility of unburned ceramsite dredged sediment preparation the best ratio of raw materials for the unburned ceramisite dry dredged in 80%, cement 3%, lime 3%, gypsum 3%, fly ash 5%, water glass 6%. with particle size distribution, cylinder compressive strength, the accumulation of dredged sediment measurement of unburned ceramisite performance. Density and water absorption rate by XRD, TG/DTG, SEM analysis of dredged sediment unburned ceramisite microstructure. (2) investigated the feasibility of technology of dredging preparation of brick. The direct incorporation of dredged sediment produced low strength brick, very Hydrated. Dredging unburned ceramisite preparation of brick by brick technology strength greatly improved, good water resistance and durability, for dredging preparation of brick feasibility process. (3) explored the dredged sediment unburned ceramisite preparation of brick. The best ratio of raw materials through orthogonal test to determine the aggregate, cement composite cementitious material content, and the influence of grain gradation strength of ceramsite brick, obtained the best ratio of the raw materials for unburned ceramisite 54.17%, cement 12.5%, fly ash 24.38%, lime 6.97%, gypsum ceramsite is L1 1.99%. the best particle size gradation of:5mm, 67%; 5-8mm, 33%. (4) studied the effect on dredging unburned ceramisite the structure and properties of unburned brick and mechanism. The fly ash unburned brick compared with compressive strength and flexural strength, contact angle, water absorption, density, frost and salt resistance, acid and alkali resistance of the measurement of sediment dredging on unburned unburned ceramisite Influence of brick performance by XRD, TG/DTG, SEM analysis of the ceramic brick structure. The results show that the ceramic unburned brick of frost and salt resistance, corrosion resistance, good durability, showed good performance, but the need to avoid the use of low concentration in salt solution. The brick with fly ash ceramsite brick strength have similar surface hydrophobicity, good water resistance, similar microstructure, and lightweight ceramsite brick, the internal structure is more compact, internal material hydration more fully.

【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU522.1;X703

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