Influence of Curing Condition on Properties of Solidified Clay in Landfill Leachate Environment

摘要

The experiments were performed to investigate the engineering properties and microstructure of cutoff wall in terms of clay-solidifying agent (CSA; or cement) contents, landfill leachate concentrations and curing time. The solidified clay was produced from leachate contaminated clay and cured in leachate of same concentration. The results indicate that CSA becomes the dominant factor influencing the property of solidified clay when the content of CSA exceeds 20% and CSA decreases the porosity instead of pore-size distribution of solidified clay. In earlier curing period, hydration of CSA takes effect, and the leachate corrosion plays a dominant role after 28 days because most of the hydration completes. While leachate cannot greatly change the pore-size distribution of solidified clay in 28 days curing time until leachate concentration exceeded 60% that is defined as critical concentration in this test. When the leachate concentration is relatively high, the aggravated corrosion occurs and a minor concentration increase will induce a drastically intensified damage in solidified clay. In engineering applications, it is crucial to prevent cutoff wall from contacting leachate of high concentration for long periods. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019