磷石膏处理方法对水泥磷石膏稳定土性能影响

Effect of Phosphogypsum Treatment Methods on the Properties of Cemented Phosphogypsum Stabilised Soil

为掌握磷石膏处理方法对水泥-磷石膏稳定土(C-PG稳定土)性能的影响,弥补其强度不足和水稳定性能差的缺陷。采用水洗法、煅烧法和水洗-煅烧混合法处理磷石膏,再对C-PG稳定土无侧限抗压强度和水稳定性能进行研究。结果表明,水洗法对C-PG稳定土水稳定性能提高较显著,且水洗2次对水稳定性能的改善效果最佳;煅烧法对C-PG稳定土无侧限抗压强度提高较显著,煅烧后抗压强度提高27.6%~41.1%;相比水洗法和煅烧法,水泥剂量为6%,磷石膏掺量为4%时,水洗-煅烧混合处理后,C-PG稳定土无侧限抗压强度和水稳定性能分别提高50.43%和10.6%。因此,推荐水洗-煅烧混合法作为C-PG稳定土中磷石膏处理方法。

In order to grasp the effect of phosphogypsum treatment methods on the performance of cemented phosphogypsum stabilised soil(C-PG stabilised soil),and make up for the defects of strength and poor water stability,phosphogypsum was treated by water washing,calcination and mixed water washing-calcination methods,and then the unconfined compressive strength and water stability performance of C-PG stabilised soil were investigated.The results showed that the water washing method improved the water stability of C-PG stabilized soil significantly,and the water stability was the best after two times of washing.The calcination method improved the unconfined compressive strength of C-PG stabilized soil significantly,and the compressive strength increased by 27.6%-41.1%after calcination.Compared with the water washing method and calcination method,when the cement dosage was 6%and the phosphogypsum dosing was 4%,the lateral compressive strength and water stability of C-PG stabilised soil increased by 50.43%and 10.6%respectively after mixed treatment of water washing-calcination.Therefore,the washing-calcining method is recommended as the treatment method of phosphogypsum in C-PG stabilized soil.