Abstract The behavior of sulfoaluminate (CSA) cements hydrated in neutral or alkaline solutions (0 M, 0.1 M, 1 M, 4 M and 8 M NaOH) was studied. 2-d, 28-d and 90-d mechanical strengths were determined, as well as the reaction rate by isothermal conduction calorimetry. The reaction products were characterised with XRD, DTA and SEM. The findings revealed differences in performance depending on whether hydration transpired at pH ≤ 14 (0.1 and 1 M) or pH > 14 (4 M and 8 M). To 0.1 M and 1 M, there is an improvement of mechanical strength than in water-hydrated pastes. The majority reaction products in these conditions were ettringite and microcrystalline aluminium hydroxide. Mechanical strength was lower in the high alkalinity (4 M and 8 M) than in the reference pastes, mainly due to the formation of different reaction products. Ettringite was unstable at 4 M and failed to form at 8 M, whilst thenardite and U-phase were detected in the 28d and later materials hydrated at both concentrations.

中文翻译：

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碱含量对硫铝酸钙（CSA）水泥水化的影响

摘要 研究了硫铝酸盐（CSA）水泥在中性或碱性溶液（0 M、0.1 M、1 M、4 M和8 M NaOH）中水化的行为。测定了 2-d、28-d 和 90-d 机械强度，以及通过等温传导量热法测定的反应速率。反应产物用XRD、DTA和SEM表征。研究结果揭示了性能差异取决于水合作用是在 pH ≤ 14（0.1 和 1 M）还是 pH > 14（4 M 和 8 M）时发生。对于 0.1 M 和 1 M，机械强度比水合糊剂有所提高。在这些条件下的主要反应产物是钙矾石和微晶氢氧化铝。高碱度（4 M 和 8 M）的机械强度低于参考糊剂，主要是由于形成了不同的反应产物。