| 摘要: |
| 采用磷酸对黄河淤积泥沙进行活性激发，再将其与石灰和河砂混合、压制成活化石灰土，并对其力学性能和微观结构进行了研究，探讨了磷酸对黄河淤积泥沙的活化效果和作用机理.结果表明：4%（质量分数）的磷酸对黄河淤积泥沙的活化效果最佳，以其为主要原料制成的活化石灰土，抗压强度、软化系数可分别达到19.3MPa和0.96，较未活化石灰土分别提高了150%和50%；磷酸使黄河淤积泥沙中—OH基团含量提高，还能与其表面的碳酸钙反应生成丝状磷酸钙晶体，从而起到活化和固结作用；活化石灰土的微观形貌与普通混凝土类似，氢氧化钙和磷酸钙晶体包裹在沙粒表面起到胶凝作用. |
| 关键词: 黄河泥沙 磷酸 活性激发 石灰土 |
| DOI：10.3969/j.issn.1007 9629.2013.05.028 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（50972099；51142006） |
|
| Activation Effect and Mechanism of Phosphoric Acid onYellow River Sediment Limes Soil |
|
LIU Jun xia1, ZHANG Lei2, YANG Jiu jun1, XIAO Yu ling1
|
|
1.School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, China;2.School of Materials Science and Engineering, Tianjin Chengjian University, Tianjin 300384, China
|
| Abstract: |
| Activity of Yellow River sediment was stimulated by phosphoric acid. Lime soil and sand soil were prepared with activated sediment and 20% of lime and river sand through press forming. Its mechanical properties and microstructures were studied; the activation effect and mechanism of phosphoric acid on the Yellow River sediment were discussed. The results show that the activation effect reaches the peak when the use level of phosphoric acid is 4%(by mass). At this use level, the compressive strength and softening coefficient of lime soil are 19.3MPa and 0.96, respectively, increasing 150% and 50% compared with the original sediment. Filamentous calcium phosphate crystal is produced by the reaction of phosphoric acid with calcium carbonate on the surface of clay particles, and —OH group content in the sediment is increased through activation of phosphoric acid. SEM and EDS analysis show that sand is wrapped around calcium hydroxide and calcium phosphate crystal. The micro morphology of lime soil activated by phosphoric acid is similar to that of ordinary concrete. |
| Key words: Yellow River sediment phosphoric acid modification limes soil |
