Mechanical properties and micro-mechanisms of RHA-cement solidified sludge

被引：0
作者：
Li L. [1 ,2 ]
Han Q. [1 ,2 ]
Yang X. [1 ,2 ]
Xiao H. [1 ,2 ]
Li W. [1 ,2 ]
Huang S. [1 ,2 ]
机构：
[1] School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan
[2] Ecological Road Engineering Research Center, Hubei University of Technology, Wuhan
来源：
Tumu Gongcheng Xuebao/China Civil Engineering Journal | 2023年 / 56卷 / 12期
关键词：
microstructure; rice husk ash; sludge; triaxial test; unconfined compressive strength;
D O I：
10.15951/j.tmgcxb.22070732
中图分类号：
学科分类号：
摘要：
The environment of rivers and lakes in many areas of China is damaged, the rate of sludge deposition is accelerated, and the sludge area is prone to serious ground or slope instability. It is of great significance to utilize the solidification/ stabilization technology for a resource use of sludge. In this work, it is proposed to use rice husk ash (RHA) and cement to solidify sludge, and the mechanical properties of solidified soil are evaluated by the tests on unconfined compressive strength and undrained triaxial consolidation of the soil. By nuclear magnetic resonance test, X-ray diffraction and scanning electron microscope, the effects of RHA ingredient on pore size, mineral composition, and micro-morphology are analyzed, and the solidification mechanism of RHA-cement for sludge is revealed. The results show that the strength of sludge can be significantly improves by RHA, the strength of RHA-cement soil increases firstly and then decreases with the increase of RHA content, and it also increases with the increase of age. When the content of cement is 8%, the optimal content of rice husk ash is 15%. The stress-strain curve of RHA-cement soil appears to be the strain-softening type, and the shear strength parameters increase with the curing age. Calcium silicate hydrate (CSH) diffraction peak may appear in the XRD pattern of the RHA-cement soil sample with a curing period of 28 days, while the peak and area of macropore in T2 distribution curve amy decrease obviously, and a large number of reticulated calcium silicate gels, which fill the pores of soil and bond soil particles, are observed in the SEM diagram. © 2023 Editorial Office of China Civil Engineering Journal. All rights reserved.
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页码：166 / 176
页数：10
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