用活性碱材料配制的粘合剂代替波特兰水泥,由于其制造过程中的二氧化碳排放,具有很高的污染潜力,越来越发达。本研究的目的是评估活性碱材料(AAM)生产的高炉矿渣的主要性能,粉煤灰,和偏高岭土。最初,粘合剂的特点是它们的化学物质,矿物学和粒度组成。稍后,制作了标本,摩尔浓度变化在4.00和5.50之间,使用参与研究的粘合剂。在制备活化溶液时,使用氢氧化钠和硅酸盐。AAM的评价性能是一致性,粘度,吸水,密度,抗压强度(固化7天),量热法,X射线衍射矿物学分析,并通过扫描电子显微镜进行形态分析。新鲜状态下的评估结果表明,偏高岭土在所研究的AAM中具有最低的可加工性指数。在硬化状态下观察到的结果表明,在正常固化和摩尔浓度为4.0和4.5mol/L的偏高岭土活化过程得到了优化,在大约30MPa的固化7天后获得抗压强度结果。在所评估的粘合剂中,飞灰活化过程是最不强烈的。这可以从在包含飞灰作为粘合剂的组合物中没有在XRD中形成的相看出。与高炉矿渣和偏高岭土不同,方钠石的形成,没有观察到八面沸石或托贝莫来石。最后,高炉矿渣在热固化过程中表现出更强烈的反应性,在固化7天后获得约25MPa的抗压强度结果。这是因为材料的反应动力学低,但可以在碱性环境中增加,以及温度的影响。从这些结果来看,结论是每种前体都有自己的激活机制,通过本研究中使用的技术观察到。从这项研究中获得的结果来看,预计本文评估的粘合剂类型的碱性活化过程将成为替代波特兰水泥的可行替代方法,从而有助于水泥技术和其他胶凝材料。
Binders formulated with activated alkali materials to replace Portland cement, which has high polluting potential due to CO2 emissions in its manufacture, have increasingly been developed. The objective of this
study is to evaluate the main properties of activated alkali materials (AAM) produced by blast furnace slag, fly ash, and metakaolin. Initially, binders were characterized by their chemical, mineralogical and granulometric composition. Later, specimens were produced, with molarity variation between 4.00 and 5.50, using the binders involved in the research. In preparing the activating solution, sodium hydroxide and silicate were used. The evaluated properties of AAM were consistency, viscosity, water absorption, density, compressive strength (7 days of cure), calorimetry, mineralogical analysis by X-ray diffraction, and morphological analysis by scanning electron microscopy. The results of evaluation in the fresh state demonstrate that metakaolin has the lowest workability indices of the studied AAM. The results observed in the hardened state indicate that the metakaolin activation process is optimized with normal cure and molarity of 4.0 and 4.5 mol/L, obtaining compressive strength results after 7 days of curing of approximately 30 MPa. The fly ash activation process is the least intense among the evaluated binders. This can be seen from the absence of phases formed in the XRD in the compositions containing fly ash as binder. Unlike blast furnace slag and metakaolin, the formation of sodalite, faujasite or tobermorite is not observed. Finally, the blast furnace slag displays more intense reactivity during thermal curing, obtaining compressive strength results after 7 days of curing of around 25 MPa. This is because the material\'s reaction kinetics are low but can be increased in an alkaline environment, and by the effect of temperature. From these results, it is concluded that each precursor has its own activation mechanism, observed by the techniques used in this research. From the results obtained in this
study, it is expected that the alkaline activation process of the types of binders evaluated herein will become a viable alternative for replacing Portland cement, thus contributing to cement technology and other cementitious materials.