%0 Journal Article
%A SHI Ming-lei
%A TIAN Xin-tao
%A WANG Hua-jin
%A YU Chang-yun
%A DU Xu-yang
%A ZHANG Rui-kun
%T Performance of Cement-Lime-Phosphogypsum Solidified Red Mud as Road Base Material
%D 2024
%R 10.11988/ckyyb.20220847
%J Journal of Yangtze River Scientific Research Institute
%P 114-120
%V 41
%N 1
%X We conducted indoor experimental research to evaluate the unconfined compressive strength, splitting strength, resilient modulus, and dry-wet and freeze-thaw durability of phosphogypsum-activated cement-lime solidified red mud for road applications. The aim was to investigate the feasibility of using this solidified red mud as a road base material. The experimental results demonstrate that the best road base performance is achieved when the curing agent mixing ratio is <i>m</i><sub>cement</sub>:<i>m</i><sub>lime</sub>:<i>m</i><sub>phosphogypsum</sub>=8:2:2. The 7-day unconfined compressive strength reaches 4.18 MPa, meeting the strength requirements of road base. The splitting strength and resilient modulus at 28-day age are 0.256 MPa and 1 020 MPa, respectively. After five cycles of dry-wet and freeze-thaw, the mass change rate is less than 2%, and the strength loss index (BDR) exceeds 80%. Microscopic analysis using a mercury intrusion test reveals that the AFt (ettringite) generated from the reaction of phosphogypsum could enhance the strength of red mud by filling pores (0.1~1 μm) in the solidified red mud. However, excessive AFt causes volumetric expansion and gives rise to micro-crack pores (1~10 μm), resulting in deteriorated strength performance. In conclusion, the performance test results indicate that the solidified red mud prepared with a ratio of <i>m</i><sub>red mud</sub>:<i>m</i><sub>cement</sub>:<i>m</i><sub>lime</sub>:<i>m</i><sub>phosphogypsum</sub>=100:8:2:2 can be effectively used as a substitute for traditional pavement base materials. This discovery provides a broader avenue for the comprehensive utilization of red mud.
%U http://ckyyb.crsri.cn/EN/10.11988/ckyyb.20220847