| 摘要: |
| 研究了C3A CaSO4·2H2O CaCO3 H2O体系水化性能，通过X 射线衍射仪、差热分析仪对该体系进行了物相分析，采用量热试验对其水化历程进行了分析.结果表明：CaCO3的引入阻碍了反应产物AFt向AFm转化，提高了AFt的稳定性；CaCO3提供的CO2-3导致AFm向单碳铝酸盐转化，而该转化重新提供的SO2-4又促进AFm向AFt转化，从而使AFm不稳定；掺入12.5%（质量分数）CaCO3和12.5%（质量分数）CaSO4·2H2O后，C3A CaSO4·2H2O CaCO3 H2O体系放热峰较纯C3A体系放热峰增强、前移，其峰值及峰值出现的时间介于纯C3A和单掺25%CaCO3体系之间，第1放热峰为C3A初始水解和AFt形成所致，第2放热峰为AFt向AFm转化以及碳铝酸盐水化物形成所致，第3放热峰为碳铝酸盐水化物大量形成所致. |
| 关键词: C3A CaSO4·2H2O CaCO3 H2O体系 水化历程 水化产物 |
| DOI：10.3969/j.issn.1007 9629.2012.06.015 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51278497） |
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| Hydration Properties of C3A CaSO4·2H2O CaCO3 H2O System |
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XIAO Jia1, MA Bao guo2, DONG Rong zhen1, XU Cai yun1
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1.School of Civil Engineering, Central South University, Changsha 410004, China;2.State Key Laboratory of Silicate Materials Science and Engineering,Wuhan University of Technology, Wuhan 430070, China
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| Abstract: |
| Hydration properties of tricalcium aluminate（C3A） gypsum（CaSO4·2H2O） calcium carbonate（CaCO3） water（H2O） composite system were studied in this paper. Hydration products were tested by X ray diffraction（XRD） and differential scanning caborimetry（DSC）, and hydration process was analyzed by calorimetric method. Results show that CaCO3 slows the speed of AFt conversion to AFm and enhanced the stability of AFt. Ion of CO2-3 provided by CaCO3 leads to single sulfur aluminate transforming to single carbon aluminate, which provides the SO2-4 to promote the AFm transforming to AFt. So CaCO3 makes AFm unstable. The calorimetric results indicate that when the system containing 12.5%（by mass） CaCO3 and 12.5%（by mass） CaSO4·2H2O, hydration heat peak is promoted and the time of hydration heat peak appeared is earlier than pure C3A sample. The value of hydration heat peak and peak appearing time are between that of the pure C3A and only mixed 25% of CaCO3. Calorimetric curve expresses the characteristic with three exothermic peaks. The first exothermic peak is generated due to C3A initial hydration and the formation of ettringite（AFt）. The second exothermic peak is sharp and narrow which is due to AFt transforming to AFm and carbon aluminate. The third exothermic peak is low, wide and continuous for a relative long time, which is due to a huge amounts of carbon aluminum formation. |
| Key words: C3A CaSO4·2H2O CaCO3 H2O system hydration process hydration product |
