改性磷石膏轻骨料在路基材料中的应用研究

Research on the Application of Modified Phosphogypsum Lightweight Aggregate in Subgrade Materials

利用电石渣对磷石膏进行改性,得到了改性磷石膏,将改性磷石膏、水泥、矿渣粉按一定比例混合,采用造粒成球工艺制成改性磷石膏轻骨料,研究了改性磷石膏掺量和养护龄期对改性磷石膏轻骨料性能的影响,分析了改性磷石膏轻骨料替代部分碎石在磷石膏基路基材料中应用的可行性。结果表明:随着改性磷石膏掺量的增加,改性磷石膏轻骨料的筒压强度和软化系数降低,吸水率增大;当改性磷石膏掺量为88%、养护龄期为60 d时,改性磷石膏轻骨料的筒压强度为5.8 MPa、吸水率为9.8%、软化系数为0.75,符合GB/T 17431.1—2010《轻集料及其试验方法第1部分:轻集料》的要求。研制的改性磷石膏轻骨料已成功应用于道路工程中。

The modified phosphogypsum was obtained by modifying phosphogypsum with carbide slag.The modified phosphogypsum,cement,and slag powder were mixed in a certain proportion,and the modified phosphogypsum lightweight aggregate was made by the granulation process.The effects of modified phosphogypsum content and curing age on the properties of modified phosphogypsum lightweight aggregate were studied,and the feasibility of using modified phosphogypsum lightweight aggregate to replace part of crushed stone in phosphogypsum-based subgrade materials was analyzed.The results show that with the increase of modified phosphogypsum content,the cylinder compressive strength and softening coefficient of modified phosphogypsum lightweight aggregate decrease,and the water absorption rate increases.When the content of modified phosphogypsum is 88%and the curing age is 60 d,the cylinder compressive strength of modified phosphogypsum lightweight aggregate is 5.8 MPa,the water absorption rate is 9.8%,and the softening coefficient is 0.75,which meets the requirements of GB/T 17431.1—2010 Lightweight Aggregates and Its Test Methods—Part 1:Lightweight Aggregates.The developed modified phosphogypsum light aggregate has been successfully used in road engineering.