Structural performance of hybrid fibres based concrete: Mechanical, durability and microstructural properties

Concrete is a globally used construction material. The building industry???s usage of raw materials depletes natural resources and increases harmful materials in the environment. Alternative goods have been discovered to help conserve the environment and natural resources. In the same context, industrial/biological wastes such as Fly Ash, Steel fibres, Banana fibres, and others are used to replace a portion of the traditional concrete mix composition. The specimens were prepared by adding different percentages of fibres to the concrete. Steel fibres (adding 0, 1, 1.5, 2, 2.5, 3, 3.5 and 4%) and banana fibres (adding 0, 1, 1.5, 2, 2.5, 3, 3.5 and 4%). The specimens were tested and compared to a standard concrete mix for compressive and flexural strength. The addition of 2% banana fibre and 4% steel fibre was optimal for improving mechanical qualities. The performance was inves-tigated by mechanical and durability testing and microstructure analysis. Water absorption sorptivity testing and quick chloride penetration tests are performed on the mixtures to ensure their durability (RCPT). Due to the introduction of C-S-H gels, combination durability has increased, which reduced porosity. Increased curing time enhanced these features. Compared to 28 days, the porosity of concrete was moderately reduced after 90 days. After 90 days of curing, the water absorption levels in the mixes dramatically decreased compared to previous stages (7, 14, 28, 56 and 90 days). From 7 to 90 days, the XRD pattern shows a decrease in quartz and mullite peaks, suggesting a decrease in void content and C-S-H gel formation in this concrete matrix.