IMPROVING FLEXIBLE PAVEMENT PERFORMANCE THROUGH THE APPLICATION OF GEOTEXTILES

Amanullah Marri, Adnan Qadir, Gul Muhammad*, Abdul Ghaffar, Shoaib Akhtar

ABSTRACT

The construction of highway pavements on soft soils faces several challenges that can impact their performance and longevity. Such as it may result in consolidation, settlement, frost, heave, moisture susceptibility, lateral spreading, increased rutting and deformation etc. Typically, various technical techniques are used to either replace or stabilize the weak subgrade soil, or it is reinforced with various natural and geosynthetic fiber types. The goal of the current study was to determine if Typar SF-37, Typar SF-56, Needle Punched, and Fiber Glass Geogrid Composite geotextiles could be applicable in any given situation for the improvement of flexible pavement performance on relative strength and support capability of soil as a function of CBR-value and resistance to axial loading as a function of uniaxial compressive strength (UCS). Although the basic functions of these geosynthetic materials are different; however, the present research was focused on their effect on relative strength and resistance to axial loading. The objectives of the present study were to identify the appropriate position of the placement of geosynthetics in the subgrade, relative improvement in the subgrade performance. According to the test results, adding geosynthetics at 0.2H (the depth of the sample obtained from the top) and 0.5H (the depth of the specimen from the top) correspondingly significantly increased the CBR and UCS values. The Geosynthetics TYPAR SF-37 and Fiber Glass Geogrid Composite Geotextiles have shown better results. From the experimental results it may be concluded that the relative strength and support capability as a function of the CBR value of weak subgrade soil was improved from 1.5 to 2.0 times by reinforcing the clayey soil with geosynthetics and a significant increase in unconfined compressive strength was also noted.

Keywords: Geosynthetics, CBR, Unconfined compressive strength, Lifecycle Cost analysis.