USE OF NANO SILICA AND NYLON FIBER TO STRENGTHEN THE ENGINEERING PROPERTIES OF CLAYEY SOIL

Expansive soil is one among the problematic soils that has a high potential for shrinking when it is dried and swelling due to change of moisture content. Expansive soils (clays) popularly known as black cotton soils in India. Due to alternate swell-shrink behavior of expansive soils causes, distress in the foundation structures such as buildings, pavements of earth retaining walls etc. Understanding the behavior of expansive soil and adopting the appropriate control measures have been great task for the geotechnical engineers. Extensive research is going on to find the solutions for black cotton Soils. In this study, Nylon Fiber has been used in the form of fibers. The effect of the stabilisation was evaluated through carrying out standard laboratory tests. The tests included the standard compaction test, unconfined compressive strength (UCS) test, California Bearing Ratio (CBR) test. The main motive of this research is to investigate the optimal combination of Nano-Silica and Nylon Fiber with clay soil. The engineering properties such as liquid limit, plastic limit, maximum dry density and unconfined compressive Strength (UCS) are analyzed with virgin soil, the soil with Nano-Silica and combination of soil with Nano-Silica and Nylon Fiber. Three different combinations of Nano-Silica at different percentages 2%, 4% & 6% are used in integration with Nylon Fiber is used in different percentages such as 2.0%, 3.0% and 4%. From these experiments, it has been analyzed that with the increase of Nylon Fiber content in addition to Nano-Silica, the UCS increases and maximum value of UCS is obtained at 6% of Nano-Silica with 2.5% of Nylon Fiber. The intermixing of Nylon Fiber with the soil acts as a reinforcing material in binding the soil particles and the ‘bridge effect’ of fiber reinforcement in soil impedes the further development of tension cracks.