Tang Yan, Jiang Han, Yang Zide, Xiong Shiyao, Xu Gaofeng, Chen Junhao, Shu Shi
Zhejiang Huadong Geotechnical Investigation & Design Institute CO Ltd, Hangzhou, 310014, China.
Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China.
Sci Rep. 2024 Jul 23;14(1):16976. doi: 10.1038/s41598-024-67923-9.
The treatment, disposal, and resource utilization of waste mud are challenges for engineering construction. This study investigates the road performance of waste mud-solidified soil and explains how solidifying materials influence the strength and deformation characteristics of waste mud. Unconfined compressive strength tests, consolidated undrained triaxial shear tests, resonant column tests, and consolidation compression tests were conducted to evaluate the solidification effect. The test results show that with an increase in cement content from 5 to 9%, the unconfined compressive strength of the waste mud-solidified soil increased by over 100%, the curing time was extended from 3 to 28 days, and the unconfined compressive strength increased by approximately 70%. However, an increase in initial water content from 40 to 60% reduced the unconfined compressive strength by 50%. With the increase of cement content from 5 to 9%, the cohesion and friction angles increased by approximately 78% and 24%, respectively. The initial shear modulus under dynamic shear increased by approximately 38% and the shear strain corresponding to a damping ratio decay to 70% of the initial shear modulus decreased by nearly 11%. The compression coefficient decreased by approximately 55%. Scanning electron microscopy and X-ray diffraction tests showed that a higher cement content led to the formation of more hydration reaction products, especially an increase in the content of AlPO, which can effectively fill the pores between soil particles, enhance the bonding between soil particles, and form a skeleton with soil particles to improve compactness. Consequently, the strength of the waste mud-solidified soil increased significantly while its compressibility decreased. This study can provide data support for dynamic characteristics of waste mud solidified soil subgrade.
废泥浆的处理、处置及资源利用是工程建设面临的挑战。本研究探讨了废泥浆固化土的路用性能，并解释了固化材料如何影响废泥浆的强度和变形特性。通过进行无侧限抗压强度试验、固结不排水三轴剪切试验、共振柱试验和固结压缩试验来评估固化效果。试验结果表明，随着水泥含量从5%增加到9%，废泥浆固化土的无侧限抗压强度提高了100%以上，养护时间从3天延长至28天，无侧限抗压强度提高了约70%。然而，初始含水量从40%增加到60%会使无侧限抗压强度降低50%。随着水泥含量从5%增加到9%，黏聚力和摩擦角分别增加了约78%和24%。动态剪切下的初始剪切模量增加了约38%，对应于阻尼比衰减至初始剪切模量70%的剪切应变降低了近11%。压缩系数降低了约55%。扫描电子显微镜和X射线衍射试验表明，较高的水泥含量导致形成更多的水化反应产物，特别是AlPO含量增加，其可有效填充土颗粒间孔隙，增强土颗粒间的粘结，与土颗粒形成骨架以提高密实度。因此，废泥浆固化土的强度显著提高而其压缩性降低。本研究可为废泥浆固化土路基的动力特性提供数据支持。
