This article investigates the role of calcium carbonate minerals in an alkali-activated system through their reaction with sodium silicate solution. The early reaction kinetics and reaction products are investigated using isothermal conduction calorimetry, in-situ XRD and in-situ FTIR. Later reaction products are identified with thermodynamic modelling and analysis of the paste samples after 8 and 90 d using XRD, TGA, DSC and mass spectrometry. After a few hours of reaction, natron precipitates as the first crystalline carbonate phase, while changes in the connectivity of silicates are observed due to the precipitation of C-S-H, which may contain Na. After 8 and 90 d, C-S-H is observed together with thermonatrite instead of natron. It is shown that calcium carbonate is not just a filler in an alkali-activated system but can provide Ca to form C-S-H and can also enhance the availability of carbonate for the formation of alkali carbonates.

本文通过碳酸钙矿物与硅酸钠溶液的反应研究了碳酸钙矿物在碱活化系统中的作用。使用等温传导量热法，原位XRD和原位FTIR研究了早期反应动力学和反应产物。通过热力学模型鉴定后期反应产物，并在8和90 d后使用XRD，TGA，DSC和质谱对糊状样品进行分析。反应数小时后，Natron沉淀为第一结晶碳酸盐相，同时由于CSH的沉淀而观察到硅酸盐的连接性发生变化，其中CSH可能含有Na。在第8天和第90天后，观察到CSH与菱铁矿而不是Natron一起。