Abstract The degree of reaction and the reaction kinetics of the reactants in geopolymers correlate closely to their mechanical properties and their durability. However, quantifying the reaction using conventional methods is challenging, especially for alkali activated siliceous fly ash with low reactivity. In the present study, a novel method to estimate the reaction kinetics of geopolymers at early ages based on the evolution of the internal relative humidity is proposed. The experimental results show increasing internal relative humidity of the two studied fly-ash based geopolymers with increasing hydration time. The internal relative humidity increases due to the reduction of the ion concentration in the pore solution as they become consumed during the reaction of the fly ash. Verified by comparison with compressive strength, heat release in isothermal calorimetry and degree of reaction measured with selective dissolution, this new method is useful to estimate the reaction kinetics of geopolymers having limited self-desiccation.

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早期地质聚合物反应动力学的估计

摘要 地质聚合物中反应物的反应程度和反应动力学与其力学性能和耐久性密切相关。然而，使用传统方法量化反应具有挑战性，特别是对于反应性低的碱活化硅质飞灰。在本研究中，提出了一种基于内部相对湿度演变来估计早期地质聚合物反应动力学的新方法。实验结果表明，随着水化时间的增加，两种研究的粉煤灰基地质聚合物的内部相对湿度增加。由于在飞灰反应过程中被消耗，孔隙溶液中的离子浓度降低，因此内部相对湿度增加。通过与抗压强度比较验证，