Dry density vs water content graph for inclusion of different percentage (0.3% to 1.2%) of nylon fiber in 15% (optimum dosage) RHA stabilized soil is shown in Fig. 9. The MDD and OMC values for different percent of nylon fiber and 15% RHA plus soil are listed in Table 9. Variation of MDD and OMC value for inclusion of different percentage of nylon fiber into optimum percent RHA treated soil are shown in Fig. 10. From the Table 9 and Fig. 10, it is clearly seen that the MDD decreases but OMC increases gradually due to inclusion of different percent of nylon fiber content into 15% RHA stabilized soil. The MDD decreases from 12.52 kN/m3 to 9.47 kN/m3 whereas the OMC increases from 17.22% to 21.47% for inclusion of different percentage (0.3% to 1.2%) of nylon fiber in 15% RHA treated soil. This phenomenon was also observed by some researchers with pozolonic materials and natural/ geosynthetic fiber stabilized soil, for instances: Sabat and Pradhan (2014); Ramesh and Kumar (2009).
This is due to the fact that different dosages of nylon fiber in 15% RHA treated soil replace more volume of soil. Here RHA and nylon fiber, both the materials have low densities. Hence the MDD values are greatly reduced by increase in percent of reinforced material (nylon fiber) in the composite mix. The increase of moisture content is also imputed by the pozzolonic reaction of RHA with the clay particles. Some ?bers, especially nylon fiber absorb water which may help to increase the OMC value.