Direct and Indirect Tensile Behavior of Cement-Zeolite-amended Sand Reinforced with Kenaf Fiber

Dealing with problematic soils is one of the most challenging parts of geotechnical engineers’ careers. Loose sand is one of them due to its low cohesion and can be found worldwide, specifically in coastal regions. Chemical stabilizers like cement are of the prevalent ones among engineers to deal with the weaknesses of loose sand. However, the substitution of these traditional stabilizers with pozzolanic materials like natural zeolite become approved since it helps reduce cement consumption and hence, lower CO۲ emission. Despite all advantages, brittle behavior is an unwelcome consequence of these stabilizers. Therefore, the aim of this study is to reduce the brittleness of the cement-zeolite-stabilized sand employing natural kenaf fibers. To this end, two cement contents, four amounts of zeolite replacement of cement, and three fiber contents in three lengths were adapted in two relative compactions (RC) to investigate the compaction, ۸-shape direct tensile strength (DTS), and indirect tensile strength (ITS) behaviors. Experimental efforts revealed that compaction behavior is sensitive to stabilizer contents and fiber content and length. The addition of the ۸% cement, increase of the zeolite up to ۵۰%, and fiber increment up to ۱.۵% led to the reduction of the compaction properties; however, optimum moisture content increased with the rise in kenaf fiber. A notable influence on the DTS and ITS behavior was observed while ۳۰% zeolite replacement in ۸%-cemented samples and reinforced with ۱% kenaf fiber with ۱۰mm length. Furthermore, a linear relationship was presented between DTS and ITS. In the end, the reinforced sample was analyzed using Scanning Electron Microscope (SEM) images.

کلیدواژه ها:

Sand ، cement ، Zeolite ، Kenaf Fiber ، compaction ، Direct Tensile Strength ، Indirect Tensile Strength ، Micro-structural analysis