Concrete steps to sustainability: A study on the mechanical performance and the durability of coated hemp twine in concrete
Date
2022-09-08
Authors
Agustines, Xavier
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Abstract
Given the strength, availability, and sustainability of natural fibers, research into their use as a reinforcement in concrete is a growing field. However, the concrete environment tends to degrade natural fibers, raising concerns about their practicality as a reinforcing material. This study attempts to address this durability issue in hemp twine by using two types of protective coatings: epoxy and methyl cellulose with silica fume. Coated and uncoated fibers were cast in concrete dog bone samples, and tensile testing of the samples and microscopy of the fibers were conducted before and after 10 cycles of wet/dry cycling. Tensile testing revealed that all the samples strengthened over the wet/dry cycle period, particularly the samples with fibers. However, only the epoxy-coated twine provided reinforcement after sample breakage. Microscopy revealed that the weak twine-concrete bonds in samples other than epoxy were mainly due to spotty surface-level bonding or a weak twine-coating bond. This research highlights the potential of epoxy coatings for natural fibers, and hints at important distinctions in the behavior of twine and individual fibers as concrete reinforcements.
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Keywords
concrete, hemp, twine, durability, coatings, green concrete