摘要: |
通过凝结时间、流动度、孔溶液pH值、抗折强度、抗压强度、吸水率、软化系数、水化热和水化产物分析测试,探究了磷建筑石膏(CPG)掺量对石膏矿渣水泥水化过程与耐水性能的影响.结果表明:随着CPG掺量的增加,石膏矿渣水泥的凝结时间缩短,流动度减小,吸水率与3 d水化累计放热量均增大;水泥净浆孔溶液的pH值在水化早期快速下降,56 d时保持不变;当CPG掺量从40%增加到70%时,56 d水泥净浆孔溶液的pH值从11.02减小到10.62,水泥胶砂的软化系数从0.98减小到0.91,主要水化产物均为二水石膏和钙矾石,并且钙矾石的含量随着CPG掺量的增加而减少. |
关键词: 磷建筑石膏 石膏矿渣水泥 水化热 吸水率 软化系数 |
DOI:10.3969/j.issn.1007-9629.2024.05.002 |
分类号:TU502.6 |
基金项目:湖北省建设科技计划项目(厅头〔2021〕2075号);国家自然科学基金资助项目(51608402) |
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Hydration and Water Resistance of Calcined Phosphogypsum Slag Cement |
LIAO Yishun1,2,3, DONG XingZhi1, LIAO Guosheng1,2,3, MEI Junpeng1,2,3
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1.School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China;2.Institute of High-performance Engineering Structure, Wuhan University of Science and Technology, Wuhan 430065, China;3.Hubei Provincial Engineering Research Center of Urban Regeneration, Wuhan University of Science and Technology, Wuhan 430065, China
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Abstract: |
The hydration and water resistance of gypsum slag cement with different contents of calcined phosphogypsum(CPG) were investigated in terms of the tests of setting time, fluidity, pH value of pore solution, flexural strength, compressive strength, water absorption, softening coefficient, hydration heat and hydration products analysis. The results indicate that the setting time of gypsum slag cement is shortened, the fluidity is reduced, and the water absorption and cumulative heat release at 3 d are increased with the increase of CPG. The pH value of pore solution of cement paste decreases fast at early hydration, but shows stable at the age of 56 d. As the CPG content increases from 40% to 70%, the pH value of pore solution of cement paste decreases from 11.02 to 10.62, the softening coefficient of cement mortar decreases from 0.98 to 0.91. The main crystalline products are gypsum and ettringite, in which the ettringite content decreases with the increase of CPG. |
Key words: calcined phosphogypsum gypsum slag cement hydration heat water absorption softening coefficient |