【作者】 王慧萍；

【导师】 胡曙光；

【作者基本信息】 武汉理工大学 ， 材料学， 2005， 硕士

【摘要】 随着我国基础设施建设的快速发展,混凝土材料用量持续增加,巨大的碎石开采量给自然环境造成严重破坏。与此同时,目前粉煤灰尤其劣质粉煤灰利用率较低,城市污泥和淤泥至今未得到妥善处置,造成环境污染。本论文以劣质粉煤灰、城市污泥和淤泥为原料,研制高强轻集料以替代天然碎石集料,不仅能使粉煤灰与淤泥得到有效的利用,而且对于节约资源、能源,保护环境,实现建材行业的可持续发展具有十分重要的意义。 本文结合高性能轻集料混凝土研究取得的成果,提出了高性能轻集料理想结构模型;以理想结构模型为指导,采用以焙烧前期动态膨胀为主,以形成连通孔,降低容重;后期以静态膨胀为主,通过液相物质填堵连通孔,调整优化孔结构,提高强度,降低孔隙率。通过二者有机结合,使轻集料内部形成理想结构;配合固相烧结以及高温下对莫来石晶化技术,优化原料组成和焙烧制度,调整轻集料孔结构和晶相组成,解决粉煤灰轻集料吸水率大、强度低的问题。 通过对粉煤灰、污泥和淤泥等原材料进行成分分析、物相分析和软化温度范围分析,进行原料配合比试验和研究,确立了原料的最优配合比。采用SEM、XRD、DTA和TG等测试技术,结合轻集料的宏观性能测试,确定了影响轻集料性能的关键因素,确立了粉煤灰与污泥的质量比为4:6的最优生产配比。工业化生产出了筒压强度为7.4 MPa,吸水率为8.5%的产品,达到了国标GB/T17431.1-1998中优质品的标准。 建立了基于轻集料生产过程中产品质量、成本高低、资源消耗和环境污染为主要控制指标的相对绿色度模糊评价理论模型,以此模型定量分析了分别本研究开发的高强优质轻集料、粘土陶粒、页岩陶粒的绿色度,证实本研究开发出的轻集料具有显著的绿色特征。更多还原

【Abstract】 With the development of the substructure building in our country, the amount of concrete consuming is increasing continuously and the exploitation of mine resource results in the serious damage of the natural environment. At the same time, the utilization rate of fly ash, especially the low quality ones is still very low and sludge are still not used and treated with well, which results in environmental pollution. This paper studies and prepares high strength light aggregate that can take place of the natural aggregate and even the natural gravel aggregate with the raw material of fly ashes and city sludge and sludge. This study can not only make use of the fly ash and sludge well but also possess very important meaning for saving source and energy and ensuring the sustainable development.The ideal structural model of high performance lightweight aggregate was set up in this paper combined the achievement received in the research work on high performance lightweight concrete. Regarding the ideal structure model as guidelines, we adopt the dynamic expanding in earlier stage for the main fact, in order to form through holes, reduce unit weight; Relying mainly on expanding in static behavior on later stage to cram and feed through holes through the liquid phase material, adjust and optimize the structure of hole, we successfully improved the strength and reduced the hole rate. Through the two-combined expanding model organically, the ideal structure of lightweight aggregate was formed. Cooperate with the solid burning technology and mullite crystallizing technology together with optimizing raw materials and sintering system, the hole structure and composites of lightweight aggregate was adjust, and its problem of low strength and high water absorption rate were solved.On the basis of analyzing the component, physical elemental analyzing, the range of Intenerated temperature of fly ash and sludge, this research experimented and studied the proportion of the raw materials, and then ascertained the optimized proportion. By adopting SEM, XRD, DTA and TG, combining the result of macro performance, the law of impact coursed by concerned factors on the performance of lightweight aggregate is summoned, which suggests that the optimized proportion of fly ash to sludge is 4:6. The industry has produced the high quality light aggregate whose strength is 7.4MPa and the water absorptive ration is 8.5%, which is accorded to the standard of the perfect production according to the national standard GB/T17431.1-1998.A evaluation model for the green degree of both process schemes and the products is set up based on the product quality, level of the cost, resource consuming and environment pollution during the manufacturing course of lightweight aggregate. The results based on this model reveals that the high performance lightweight aggregate manufactured according to the research work in this paper has an obvious highly relative degree of green.更多还原