Durability of chemically treated coir geotextiles coated with epoxy resin in different degradation environments

Abstract

The high water absorption of coir fibers leads to poor durability, which limits the application of coir geotextiles in engineering. In this paper, the changes of tensile strength and elongation at break of chemically treated coir geotextiles coated with epoxy resin (CGCE) in chemical, physical and natural degradation environments were studied. The macro and micro morphology of CGCE at the final degradation stage in various environments were analyzed, and the degradation rules of CGCE were compared with untreated coir geotextiles (UCG) and chemically treated coir geotextiles (CCG). The results show that UCG, CCG and CGCE have the slowest tensile strength loss in sea water, followed by pure water and hydrochloric acid (HCl) solution, with the fastest tensile strength loss observed in NaOH solution. As the number of dry–wet cycles increases, the tensile strength loss of CGCE is less than that of UCG and CCG at the same exposure time. Additionally, the tensile strength loss of CGCE decreases as burial depth increases. The cross-sectional micro morphology of CGCE under different degradation environments shows varying degrees of separation and fiber pull-out between coir fibers and the epoxy resin.