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Advances in Materials Science and Engineering
Volume 2017 (2017), Article ID 5069581, 13 pages
https://doi.org/10.1155/2017/5069581
Research Article

An Experimental Study on Solidifying Municipal Sewage Sludge through Skeleton Building Using Cement and Coal Gangue

1Institute of Poromechanics, Wuhan Polytechnic University, Wuhan 430023, China
2Department of Civil, Architectural, and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA

Correspondence should be addressed to Haijun Lu

Received 31 August 2016; Revised 24 December 2016; Accepted 23 January 2017; Published 16 February 2017

Academic Editor: Charles C. Sorrell

Copyright © 2017 Jiankang Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The municipal sewage sludge typically has very high water content and low shear strength. Conventional methods of lime and cement solidification of municipal sewage sludge often suffer high cost, significant drying shrinkage, frequent cracking, high hydraulic conductivity, and low strength. To overcome these shortcomings, in this paper a skeleton-building method was used to solidify municipal sewage sludge in which coal gangue, cement and clay, and fiber were used as skeleton materials, cementation materials, and filling materials, respectively. Comprehensive laboratory tests including cracking, nitrogen adsorption, triaxial shearing, and permeability tests were performed to determine cracking, pore structure, shear strength, and hydraulic conductivity of municipal sewage sludge solidified with different proportions of coal gangue, cement, fiber, and clay. Based upon the experimental results, the mechanisms of the skeleton building using cement and coal gangue were discussed and factors controlling the mechanical and hydraulic behavior of the solidified soils were analyzed at both microscopic and macroscopic levels. Based upon the test results and analyses, recommendations were made for solidifying municipal sewage sludge through skeleton building using cement and coal gangue. The solidified soils have high soil strength, high resistance to cracking, and low hydraulic conductivity which are sufficient for being used as landfill liner.