Combined effect of nano-silica and randomly distributed fibers on the strength behavior of clay soil

• Published in: Nanotechnology for environmental engineering Vol. 7; no. 1; pp. 23 - 34
• Main Authors: Kulanthaivel, P., Selvakumar, S., Soundara, B., Kayalvizhi, V. S., Bhuvaneshwari, S.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.03.2022; Springer Nature B.V
• Subjects: Clay; Clay soils; Compaction; Compressive strength; Dry density; Earth and Environmental Science; Earth Sciences; Environment; Environmental Science and Engineering; Fibers; Laboratories; Laboratory tests; Mechanical properties; Microscopic analysis; Modulus of elasticity; Moisture content; Nanoparticles; Nanotechnology and Microengineering; Original Paper; Polypropylene; Shear strength; Silica; Silicon dioxide; Soil compaction; Soil investigations; Soil moisture; Soil strength; Soils; Transmission electron microscopy; Water content; Clay soil; Microscopic analysis; Compaction; Nano-silica; Strength; Polypropylene fiber
• ISSN: 2365-6379; 2365-6387
• DOI: 10.1007/s41204-021-00176-3

The current study presents the laboratory investigation on the use of nano-silica (0.2, 0.4, 0.8 and 1.0%) and polypropylene fiber (0.25, 0.50, 0.75 and 1.0%) in problematic clayey soil to enhance the shear strength and compaction characteristics. From the Transmission electron microscopy (TEM) analysis, it is observed that the diameter of nano-particles used in this study was in the range of 10–20 nm. The nano-particles have a spherical shape and amorphous in nature. Extensive laboratory tests such as the standard Proctor compaction test and unconfined compressive strength test have been conducted on untreated and polypropylene fiber along with nano-silica treated clayey soil. The outcomes showed that the addition of polypropylene fiber in poor soil, increase the maximum dry density and reduce the optimum moisture content of the soil. Whereas, the addition of nano-silica to the clay soil results in reduced maximum dry density and increased optimum moisture content. Unconfined compressive strength of clay soil is increased with the addition of polypropylene fiber and nano-silica to the clay soil. The optimum dosage of polypropylene fiber and nano-silica added to the poor soil was 0.75% and 0.8%, respectively. The Young’s modulus of clay soil was increased with the addition of polypropylene fiber and nano-silica. The microscopic analysis confirmed that C–S–H gel was the main cementitious product, and the inclusion of nano-silica can contribute to a denser packing of soil particles.