Title: Mechanical properties and failure mechanism of cemented red clay under chemical erosion environment
Authors: Xiangqian Li; Yuyou Yang; Haiqing Zhang; Yucheng Yi
Addresses: School of Engineering and Technology, China University of Geosciences, Beijing, 100083, China ' School of Engineering and Technology, China University of Geosciences, Beijing, 100083, China ' School of Engineering and Technology, China University of Geosciences, Beijing, 100083, China ' School of Engineering and Technology, China University of Geosciences, Beijing, 100083, China
Abstract: This paper presents an experimental investigation on the strength behaviour of red clay improved by cement, considering initial water content (ω), cement content and curing pH levels. Along with the unconfined compressive tests, acoustic emission signals were detected to investigate the compression failure. It was shown that unconfined compressive strength (UCS) of the cement red clay rose first and fell later with water content increasing, and maximum UCS was reached at ω = 75%. As cement content increased from 15% to 30% under water content of 75%, UCS of blocks increased from 1.03 MPa to 6.09 MPa. Stress-strain curves of blocks curing in acid condition were divided into four stages: microcracks closure, elastic deformation and stable crack propagation, rapid crack growth and final failure. Acoustic emission signals detected in compression process showed that a large number of microcracks occurred in the second stage with more in the third stage.
Keywords: red clay; cement; cemented soil; mechanical properties; failure mechanism; chemical corrosion; acoustic emission; chemical erosion; unconfined compressive strength; UCS; water content; stress strain curves; microcrack closure; elastic deformation; crack propagation; crack growth; final failure; AE signals; microcracks; China; block curing; acid.
International Journal of Environment and Pollution, 2016 Vol.59 No.2/3/4, pp.156 - 168
Received: 12 Nov 2015
Accepted: 11 Mar 2016
Published online: 20 Oct 2016 *