Long-Term Performance of Rural Roads Reinforced with Coir Geotextile – A Field Study

ABSTRACT

India has one of the largest road networks in the world, aggregating to about 56 lakh km at present. At sites with inadequate CBR, problems of excessive rutting are very common. In order to overcome this ground improvement techniques such as inclusion of coir geotextile is a good option. Coir geotextiles are manufactured with coir fibers, extracted from the husk of coconut, and are more durable than other natural fibers due to high lignin content. Construction of pavements strengthened with coir geotextiles makes it cost-effective and eco-friendly. In this paper, the results of the performance study conducted on five coir geotextile reinforced and unreinforced roads in different parts of Kerala, after three to 6 years of construction are reported. Coir geotextile had been placed in between subgrade and sub base. The performance was evaluated by conducting Benkelman Beam Deflection (BBD), Field CBR and Dynamic Cone Penetration (DCP) test on reinforced and unreinforced roads. A reduction in characteristic deflection thereby decrease in bituminous Macadam overlay, decrease in DCP Index and improvement in in-situ CBR values ranging from 22% to 178% were obtained for roads on all types of soil. A correlation was also developed between field CBR and field DCPI.

摘要

印度拥有世界上最大的公路网之一，目前总里程约5600万公里. 在CBR不足的现场，车辙过度的问题非常普遍. 为了克服这种地基处理技术，如加入椰壳土工布是一个很好的选择. 椰壳土工布是用椰壳中提取的椰壳纤维制成的，由于木质素含量高，比其他天然纤维更耐用. 采用土工织物加固的路面结构使其具有成本效益和生态友好性. 本文报道了喀拉拉邦5种不同地区的土工布加筋和无筋道路经过3～6年的施工后的性能研究结果. 在路基和底基层之间铺设了椰壳土工布。通过在加筋和非加筋道路上进行Benkelman梁挠度（BBD）、现场CBR和动力触探（DCP）试验，对其性能进行了评价. 在所有类型的土壤上，道路的特征挠度减少，从而沥青碎石覆盖层减少，DCP指数减少，现场CBR值从22%提高到178%. 在田间CBR和田间DCPI之间建立了相关关系.

KEYWORDS:

• Subgrade
• coir geotextile
• characteristic deflection
• overlay
• dynamic cone penetration index
• field CBR

Additional information

Funding

The financial support provided by Coir Board, Government of India for conducting the experimental investigation is greatly acknowledged by the authors.