Field Evaluation of Coir Geotextile Reinforced Subgrade for Low Volume Pavements

Abstract

This investigative study focuses on the response of full scale coir reinforced low volume roads when subjected to static loading. The test track of 1.736 km consists of a control section and eight reinforced sections including two types of coir geotextiles and subbase with varying thickness. An assessment of the general behavior of coir geotextile-reinforced sections, to static plate load tests, California Bearing Ratio tests, geogauge and dynamic cone penetration tests is done for evaluation. The study summarizes the results of the executed tests on the reinforced test track in comparison to the unreinforced one. The results reveal that the geotextile with higher apparent opening size is not as good as that of the finer mesh geotextile. A maximum of 112% improvement in the elastic modulus of subgrade is achieved by using a woven coir geotextile of 740 g/m2 mass per unit area whereas 70% increment is attained while using an alternate geotextile of 365 g/m2 mass per unit area. The elastic modulus values are determined from the various field tests and the overall damage analysis is carried out using KENPAVE software. From the analysis, it is noted that an appreciable decrease in the aggregate layer thickness is achieved by using coir geotextile as reinforcement. Use of coir geotextiles in pavements as a reinforcement can therefore help in reducing the demand and consumption of fast-depleting natural resources.

Keywords

• coir geotextile
• reinforcement
• subgrade
• elastic modulus
• kenlayer
• low volume roads