This study focused on the development of an innovative calcium carbonate (CC)-raw bentonite (RB) mortar for high temperature purposes. The main strategy proposed in this work relies on the synergistic thermal and chemical activation of CC/RB-based mortar to produce a hardened material with optimal engineering properties. Instead of calcining RB before alkali-activation, thermochemical activation was applied to the CC/RB-based mortar to produce a thermally stable hardened material. This process resulted in the formation of stable minerals, such as wollastonite and gehlenite, alongside the formation of solidified melt at high temperatures, leading to the densification of the microstructure and the creation of a hardened material with higher performance and stability compared to cured samples. The hardened mortar with the highest compressive strength value (∼57 MPa) was obtained by adjusting the CC/RB weight ratio at 50 wt%/50 wt%, Na2O concentration of 7.5 wt%, sand/waste glass (WG) aggregate weight ratio of 25 wt%,/75 wt%, and exposure temperature of 1000 °C. Surprisingly, the proposed strategy produced a hardened material with a considerable compressive strength of ∼23 MPa without adding Na2O. Accordingly, the proposed approach can resolve the economic and environmental shortcomings of using a chemical alkali-activator.

中文翻译：

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指定一种新策略，通过在高温下通过再矿化工艺生产高强度碳酸钙原料膨润土基砂浆


本研究的重点是开发一种用于高温目的的创新碳酸钙 （CC） -未加工膨润土 （RB） 砂浆。这项工作中提出的主要策略依赖于 CC/RB 基砂浆的协同热活化和化学活化，以生产具有最佳工程性能的硬化材料。在碱活化之前，不是煅烧 RB，而是将热化学活化应用于基于 CC/RB 的砂浆，以产生热稳定的硬化材料。这个过程导致形成稳定的矿物，如硅灰石和硅灰石，同时在高温下形成凝固的熔体，导致微观结构致密化，并产生与固化样品相比具有更高性能和稳定性的硬化材料。通过在 50 wt%/50 wt%、Na2O 浓度为 7.5 wt%、砂/废玻璃 （WG） 骨料比 25 wt%/75 wt% 和 1000 °C 暴露温度下调整 CC/RB 重量比，获得抗压强度值最高 （∼57 MPa） 的硬化砂浆。 令人惊讶的是，所提出的策略在不添加 Na2O 的情况下产生了一种具有 ∼23 MPa 相当大的抗压强度的硬化材料。因此，所提出的方法可以解决使用化学碱活化剂的经济和环境缺陷。