| 摘要: |
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| 关键词: 磷石膏 复合胶凝材料 力学性能 化学预处理 |
| DOI：103969/j.issn.1007 9629202001030 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51678442，51478348，51508404)；国家高铁联合基金项目(U1534207)；中央高校基本科研业务费专项资金资助项目 |
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| Effect of Chemical Pretreatment on the Properties of Phosphogypsum BasedComposite Cementitious Materials |
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CHEN Qianhao, JIANG Zhengwu
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Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education,Tongji University, Shanghai 201804, China
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| Abstract: |
| The effects of chemical pretreatment with different liquid solid ratio and solution concentration on the pH value and residual phosphorus content of phosphogypsum and the setting time and mechanical properties of phosphogypsum based composite cementitious materials were studied. The influence of the liquid solid ratio and solution concentration on the composition and micro morphology of the hydration products of phosphogypsum based composite cementitious materials were further analyzed. The test results show that the pH value of phosphogypsum has a quadratic function relationship with the liquid solid ratio and a linear function relationship with the pretreatment solution concentration. The increase of liquid solid ratio can reduce the residual phosphorus content, while the increase of solution concentration inhibits the phosphorus removal. Alkali solution pretreatment can increase the pH value of phosphogypsum to produce an acceleration effect, while deionized water or tap water pretreatment can reduce the retardation effect by reducing residual phosphorus content. Chemical pretreatment can promote the hydration reaction, accelerate the formation of early ettringite, shorten the setting time and improve the early strength. |
| Key words: phosphogypsum composite cementitious material mechanical property chemical pretreatment |
