Effect of Lime Sludge, Polypropylene Fiber on Unconfined Compressive Strength and Shrinkage Behavior of Kaolinite Clay

摘要

The paper presents results of a comprehensive investigation on utilization of lime sludge (a waste material from water treatment plant) and polypropylene fiber on unconfined compressive strength (UCS) and shrinkage behavior of commercially available kaolinite clay. Effects of adding various quantities of fiber i.e., 0%, 0.5%, 1.0%, and 1.5% and lime sludge i.e., 2%, 4%, 6%, and 8% were investigated and evaluated. Both fiber and lime sludge samples were added to kaolinite (EPK clay) by dry weight of the EPK clay. The UCS samples were prepared at optimum moisture content (OMC) and corresponding maximum dry unit weight from standard Proctor compaction test results. The addition of fibers and lime sludge resulted in significant influence on engineering properties with curing period. Scanning electron microscopy (SEM) analyses were conducted on samples after shearing. Results show that with the increase in the lime sludge content, UCS value initially increased, followed by a slight decrease. An increase in curing period resulted in an increase in the unconfined compressive strength. Also, an increase in the lime sludge content led to a reduction in shrinkage potential. Increase in the fiber content increased the UCS value. Also an increased shrinkage potential was observed with the increase in fiber content. Based on the SEM analyses, addition of fiber created a physical interaction between the fiber and the EPK clay. Whereas, the use of lime sludge induced a chemical reaction between the EPK clay and the lime sludge which changed the soil fabric significantly.