碱矿渣再生骨料混凝土试验研究

发布时间：2018-09-08 07:23

【摘要】：矿渣是一种冶金工业副产品,在我国排放量巨大,其堆积和排放对环境造成不利影响。矿渣目前主要用于生产矿渣水泥或作为混凝土的外掺料,且利用率不高。研究发现用碱激发矿渣活性并用于制作碱矿渣水泥和混凝土,其性能优异,对资源的消耗少,是一种十分环保的材料。随着我国城镇化的加快,大量构筑物被拆除,随之而来的是大量的固体废弃物,其中大部分是废弃混凝土。将废弃混凝土破碎加工成为再生骨料配制混凝土的研究也受到越来越多的关注。而将碱矿渣水泥与再生骨料两者结合使用是一个新的思路,在国内这方面研究较少。这种新型材料的研究,对节约资源、保护环境的可持续发展战略具有重要意义。本课题利用云南昆钢嘉华水泥建材有限公司生产的磨细高炉矿渣粉作为原材料,对碱矿渣水泥和碱矿渣再生骨料混凝土进行试验研究。通过调整碱浓度、水玻璃模数、溶矿比三个因素设计正交试验方案,运用极差法分析法和方差分析法分析这三个因素对碱矿渣水泥性能(凝结时间、流动度、胶砂强度等)的影响程度,找出碱矿渣水泥较优配合比成型试件,并利用扫描电镜对碱矿渣水泥内部结构进行微观试验分析。在此基础上,用较优配比的碱矿渣水泥(碱浓度6%、水玻璃模数1.0、溶矿比0.55),改变再生骨料替代率和再生骨料附加水不同加水方式,配制碱矿渣再生骨料混凝土。研究再生粗骨料替代率(0、20%、40%、60%、80%、100%)和再生粗骨料附加水不同加水方式(一次加水、二次加水)对碱矿渣再生骨料混凝土的工作性能、干燥收缩、抗压强度和弹性模量的影响规律。再生骨料替代率低于60%时,随着再生骨料替代率的增加,对碱矿渣再生骨料混凝土的工作性能、干燥收缩、抗压强度和弹性模量影响不大。用二次加水拌制碱矿渣再生骨料混凝土,溶矿比与理论值接近,其干燥收缩、抗压强度、弹性模量测试结果更好。该课题研究,不仅为矿渣微粉的推广应用找到新途径,同时还可为碱矿渣再生骨料混凝土在工程中的应用奠定理论基础。
[Abstract]:Slag is a by-product of metallurgical industry. Slag is mainly used to produce slag cement or admixture of concrete, and the utilization ratio is not high. It is found that alkaline activated slag can be used to make alkali slag cement and concrete with excellent properties and low consumption of resources. It is a kind of environmental protection material. With the acceleration of urbanization in China, a large number of structures have been demolished, followed by a large number of solid waste, most of which is waste concrete. More and more attention has been paid to the process of crushing waste concrete into recycled aggregate to prepare concrete. The combination of alkali slag cement and recycled aggregate is a new idea. The research of this new material is of great significance to the sustainable development strategy of saving resources and protecting the environment. Using the pulverized blast furnace slag powder produced by Jiahua cement Building Materials Co., Ltd of Yunnan Kunming Iron and Steel Co., Ltd as raw material, the test study on alkali slag cement and recycled aggregate concrete from alkali slag is carried out. By adjusting the concentration of alkali, the modulus of sodium silicate and the ratio of dissolved ore to mineral solution, the orthogonal test scheme was designed. The performance of alkali slag cement (setting time, fluidity) was analyzed by means of range analysis method and variance analysis method. The optimum mix ratio of alkali slag cement was found out, and the microstructure of alkali slag cement was analyzed by scanning electron microscope. On this basis, the recycled aggregate concrete of alkali slag was prepared by changing the replacement rate of recycled aggregate and the different ways of adding water to recycled aggregate with the optimum ratio of alkali slag cement (alkali concentration 6, water glass modulus 1.0, dissolved ore ratio 0.55). The effects of the replacement ratio of recycled coarse aggregate (020%) and recycled coarse aggregate plus water (primary water, secondary water) on the working performance, drying shrinkage, compressive strength and elastic modulus of recycled aggregate concrete were studied. When the replacement ratio of recycled aggregate is lower than 60, with the increase of the replacement ratio of recycled aggregate, there is little effect on the working performance, drying shrinkage, compressive strength and elastic modulus of alkali slag recycled aggregate concrete. The ratio of dissolved ore to the theoretical value of reclaimed aggregate concrete made of alkali slag mixed with secondary water is close to the theoretical value, and the test results of drying shrinkage, compressive strength and elastic modulus are better. The research will not only find a new way for the application of slag powder, but also lay a theoretical foundation for the application of alkali slag recycled aggregate concrete in engineering.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

【参考文献】