【作者】 于霖；

【导师】 卢红霞；

【作者基本信息】 郑州大学 ， 材料学， 2010， 硕士

【摘要】 碱激发矿渣胶凝材料跟传统水泥相比,具有较高的强度,较低的水化热,以及较好的快硬性、抗腐蚀性、抗冻性、护筋性等优异的性能,并且生产工艺简单、投资少、能耗低、污染小、矿渣的利用率高,目前成为胶凝材料研究领域的热点。本论文研究利用高炉矿渣制备胶凝材料,选取了氢氧化钠、碳酸钠、硫酸钠、硅酸钠以及氢氧化钠和硅酸钠的混合物作为激发剂,并研究了激发剂的掺入量、水固比、养护时间和养护温度、矿渣微粉的粒度等试验参数对胶凝材料的水化率、密度、抗压强度、抗折强度、凝结时间、安定性和抗硫酸腐蚀性等性能的影响。使用XRD、XRF、SEM和TEM等检测手段对矿渣的相成分、化学成分、微观形貌进行了表征。对矿渣的密度、粒度、粉磨性能进行了检测。依照国标文件对矿渣的碱性系数、质量系数、活性系数、水硬系数及放射性进行了分析。结果表明,矿渣的主晶相为玻璃体,并含有少量钙铝黄长石结晶相,能够满足制备胶凝材料的要求。使用比表面积为663.40 m2/kg的矿渣,以掺入量为6 wt.%的硅酸钠为激发剂,0.25的水固比制备出胶凝材料浆体,在温度为20±1℃,相对湿度为75±5%,压力为1atm的养护箱中进行养护,制得的胶凝材料3天、28天抗压强度和抗折强度分别为37.43MPa、57.22MPa,6.10MPa、7.59MPa,密度为2.31g/cm3,初凝时间和终凝时间分别为52分钟和111分钟,安定性及抗硫酸腐蚀性均较好。激发剂的种类及其掺入量对胶凝材料的性能有很大影响。硅酸钠作为激发剂,与氢氧化钠、碳酸钠和硫酸钠等作为激发剂相比,能够获得较高的28天抗压强度和抗折强度,较高的水化率、密度、抗硫酸腐蚀性和安定性。氢氧化钠作为激发剂能够获得较短的凝结时间,和较高的3天抗压、抗折强度。碱激发矿渣胶凝材料的水化反应并不完全,产物的主晶相为水化硅酸钙凝胶和未水化的玻璃态矿渣。水固比越大,硅酸钠激发矿渣胶凝材料的密度越小,凝结时间越长,抗压强度和抗折强度越低。随着养护时间的增长,硅酸钠激发矿渣胶凝材料的水化率、密度、抗压强度和抗折强度均提高；提高养护温度有利于3天抗压强度和密度的提高。矿渣的粒度越小,硅酸钠激发矿渣胶凝材料的凝结时间越短；矿渣粒度为0.05mm～0.074mm时,有利于提高胶凝材料的抗压强度和密度。更多还原

【Abstract】 Alkali-activated slag cementitious material has become a research hotspot of cementitious materials field at present, due to its excellent performances compared with cement, such as higher intensity, lower hydration heat, and higher performances of rapid hardening, corrosion resistance, frost resistance and reinforcing steel bar protection, coupled with its production of simple process, low investment, low energy consumption, little pollution, high utilization of slag and so on.Cementitious material was prepared by using blast-furnace slag as raw material, as well as sodium hydroxide, sodium carbonate, sodium sulfate, sodium silicate, and a mixture of sodium hydroxide and sodium silicate as activators. Effects of activator content, water-solid ratio, curing time, temperature, and granularity of slag powder on the properties of cementitious material such as hydration degree, density, compressive and flexural strength, setting time, stability and sulfuric acid corrosion resistance, etc. were studied.Phase composition, chemical composition and microstructure of blast-furnace slag were characterized by using XRD, XRF, SEM and TEM. Density, granularity and grinding performance of slag were studied. Also basicity factor, quality coefficient, activity coefficient, hydraulic coefficient and radiation of slag were analyzed according to the Chinese national standard documents. The results showed that the slag was mainly composed of glassy materials with a small amount of Gehlenite, which could meet the requirement of preparation of cementitious material.When sodium silicate content was 8 wt.%and water-solid ratio was 0.25, cementitious material prepared from slag specific surface area of 663.40 m2/kg, cured at a atmospheric cabinet of temperature 20±1℃and relative humidity 5±5%, developed 37.43MPa and 6.10MPa compressive and flexural strength at 3 days, 57.22MPa and 7.59MPa at 28 days. Moreover, the density was 2.31g/cm3, the initial and final setting time was 52 minutes 111 minutes respectively, the stability and sulfur resistant was relatively good.The type and content of activators affected the performance of cementitious material obviously. Cementitious material using sodium silicate as activator obtained higher 28 days compressive and flexural strength, as well as higher hydration degree, density, sulfuric acid corrosion resistance and stability compared with sodium hydroxide, sodium carbonate and sodium sulfate. Using sodium hydroxide as activator obtained a relatively shorter setting time and higher 3 days compressive and flexural strength. XRD patterns showed that the produced cementitious material was mainly calcium silicate hydrates gel (CSH gel) mixed with un-hydrated slag, which indicated that the hydration reaction of the slag was not fully completed.To the sodium silicate-activated slag cementitious material, the higher the water-solid ratio, the smaller the density, and, the longer the setting time, the lower the compressive and flexural strength.With the increase of curing time, the hydration degree, density, compressive and flexural strength of sodium silicate-activated slag cementitious material all represented enhancement respectively.High curing temperature was proved to be effective in improving the 3 days compressive strength and density of sodium silicate-activated slag cementitious material.The results also showed that, the smaller the granularity of the slag, the shorter the setting time of the sodium silicate-activated slag cementitious material. Granularity of 0.05mm-0.074mm was found to be more suitable for the compressive strength and density of cementitious materials when compared to any other chosen granularity.更多还原