Abstract This study aims to provide a better understanding of the autogenous shrinkage of slag and fly ash-based alkali-activated materials (AAMs) cured at ambient temperature. The main reaction products in AAMs pastes are C-A-S-H type gel and the reaction rate decreases when slag is partially replaced by fly ash. Due to the chemical shrinkage and the fine pore structure of AAMs pastes, drastic drop of internal relative humidity is observed and large pore pressure is generated. The pore pressure induces not only elastic deformation but also a large creep of the paste. Besides the pore pressure, other driving forces, like the reduction of steric-hydration force due to the consumption of ions, also cause a certain amount of shrinkage, especially in the acceleration period. Based on the mechanisms revealed, a computational model is proposed to estimate the autogenous shrinkage of AAMs. The calculated autogenous shrinkage matches well with the measured results.

中文翻译：

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碱活化渣粉煤灰浆自收缩机理

摘要 本研究旨在更好地了解在环境温度下固化的矿渣和粉煤灰基碱活化材料 (AAM) 的自收缩。AAMs糊剂中的主要反应产物为CASH型凝胶，当炉渣部分被粉煤灰替代时反应速率降低。由于AAMs糊剂的化学收缩和细孔结构，观察到内部相对湿度急剧下降并产生大孔压。孔隙压力不仅会引起弹性变形，还会引起膏体的大蠕变。除了孔隙压力外，其他驱动力，如因离子消耗而导致的空间水合力降低，也会引起一定量的收缩，尤其是在加速期。根据揭示的机制，提出了一种计算模型来估计 AAM 的自收缩。计算出的自收缩与测量结果非常吻合。