Abstract Organic compounds, often used in cement systems as admixtures, may affect the crystallisation and carbonation kinetics of Ca(OH)2, an important phase of hydrated cement. Here, we investigated changes in Ca(OH)2 morphology in the presence of 3 organic compounds, commonly encountered in cement and lime-based materials: sucrose, pectin and calcium lignosulfonate. The additives were introduced either before or after lime slaking to determine the influence of temperature. Ca(OH)2 crystals and supernatant solutions were characterised at time of slaking and after 6 months of ageing using scanning electron microscopy, X-ray diffraction and optical emission spectroscopy. Our results indicate that the morphology of Ca(OH)2 crystals is modified by the characteristics of the organic molecules which promote formation of Ca(OH)2 with habits that can result in faster carbonation, an effect that is detrimental to cement used in reinforced concrete. These effects are enhanced when the additives are introduced before slaking, likely as a result of thermal degradation.

中文翻译：

---

有机添加剂对石灰熟化过程中氢氧化钙结晶的影响

摘要 经常在水泥系统中用作外加剂的有机化合物可能会影响 Ca(OH)2（水化水泥的重要相）的结晶和碳酸化动力学。在这里，我们研究了在水泥和石灰基材料中常见的 3 种有机化合物存在时 Ca(OH)2 形态的变化：蔗糖、果胶和木质素磺酸钙。在石灰消解之前或之后加入添加剂以确定温度的影响。Ca(OH)2 晶体和上清液在熟化时和老化 6 个月后使用扫描电子显微镜、X 射线衍射和光学发射光谱进行表征。我们的结果表明，Ca(OH)2 晶体的形态被有机分子的特征所改变，这些有机分子促进了 Ca(OH)2 的形成，其习惯可以导致更快的碳化，这种影响对用于钢筋的水泥有害。具体的。当在熟化之前加入添加剂时，这些效果会增强，这可能是热降解的结果。