| 摘要: |
| 在以大掺量湿磨改性磷石膏浆体、粒化高炉矿渣粉为主要原料制备过硫磷石膏矿渣水泥（PPSC）的基础上，以力学性能为导向，设计制备了过硫磷石膏矿渣水泥路面基层材料（PGBM），并对其微观结构及力学性能进行了研究.结果发现：PPSC含有矿物相石英（α-SiO2）、二水石膏（CaSO4·2H2O）和水化产物钙矾石（Ettringite）3种主要矿物成分；PPSC的矿物成分和微观结构特点影响着PGBM的无侧限抗压强度，进而影响PGBM的水稳性，但PGBM与PPSC的无侧限抗压强度增长率保持一致，且PGBM的抗冲刷能力与其无侧限抗压强度发展规律也具有一致性；不同配比的各组基层试件水稳性较好，其软化系数均大于90%；PPSC掺量为5%时，PGBM的7 d无侧限抗压强度即可满足路面基层强度的规范要求，而PPSC掺量为15%的PGBM在28 d龄期时出现无侧限抗压强度下降和冲刷量升高现象，分析原因是由于PPSC内部过量钙矾石的形成导致试件膨胀开裂所致. |
| 关键词: 过硫磷石膏矿渣水泥 路面基层材料 微观结构 力学性能 水稳性 |
| DOI：10.3969/j.issn.1007-9629.2022.03.002 |
| 分类号:TU528.01 |
| 基金项目:2020年度中山市第三批科技发展专项资金资助项目（2020-18）；中山市武汉理工大学先进工程技术研究院科研项目（WUT202011）；湖北省交通运输厅科技项目（2020-2-1-10） |
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| Microstructure and Mechanical Properties of Excess-Sulfate Phosphogypsum Slag Cementitious Road Base Material |
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XU Fang1, LI Heng1, SUN Tao2,3, NIE Yutao1, DING Chao2
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1.Faculty of Engineering， China University of Geosciences， Wuhan 430074， China;2.State Key Laboratory of Silicate Materials for Architectures， Wuhan University of Technology， Wuhan 430070， China;3.Wuhan University of Technology Advanced Engineering Technology Research Institute of Zhongshan City， Zhongshan 528437， China
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| Abstract: |
| Based on the preparation of excess-sulfate phosphogypsum slag cement （PPSC） with a large amount of wet grinding modified phosphogypsum paste and granulated blast furnace slag powder as the main raw materials， the excess-sulfate phosphogypsum slag cementitious road base material （PGBM） was designed and prepared based on mechanical properties， and its microstructure and mechanical properties were studied. The results show that the PPSC contains three main mineral components： mineral phase quartz （SiO2）， dihydrate gypsum （CaSO4·2H2O） and hydrate product ettringite， and the mineral phase and microstructure affect the unconfined compressive strength and then affect the water stability of PGBM， but the growth rate of the unconfined compressive strength of the PGBM is consistent with the excess-sulfate phosphogypsum slag cement， and the erosion resistance of PGBM is also consistent with the development of its unconfined compressive strength. The base specimens of different proportions have good water stability， and their softening coefficients are all greater than 90%； when the content of PPSC is 5%， the 7 d unconfined compressive strength of PGBM can meet the specification requirements of pavement base strength； while the 15% PPSC content of PGBM shows a decrease in strength and increase in scour capacity at 28 d curing age. The reason is that the formation of excessive ettringite inside the PPSC causes the specimen to expand and crack. |
| Key words: excess-sulfate phosphogypsum slag cement （PPSC） road base material microstructure mechanical property water stability |
