Permeation characteristics and durability aspects for sustainable concrete

This study investigates the durability indicators for sustainable concrete produced by adding both crumbed rubber and steel fibres that are removed from waste tyres to the concrete mixes. Crumb rubber was treated by submersion in sodium hydroxide and then used to partially replace 10% and 30% of fine aggregates in the concrete mix. Extracted steel fibres were added at the rate of 1% and 2% per volume of each mix. The compressive strength was recorded, and a non-destructive air permeability test was used to assess permeation characteristics of studied specimens and to correlate the results with compressive strength results. It was found that with the increase in the steel fibres percentage while keeping the rubber content constant resulted in
increased compressive strength of concrete. Rubberized concrete of 10% crumb rubber and 1% steel fibres exposed to oven drying at 105°C for 12 hours exhibited an increase in compressive strength. The addition of crumb rubber and steel fibres as a partial fine aggregate replacement resulted in increasing the air permeability of the concrete to different degrees depending on the percentages used. This study showed that waste tyres extracts can be a viable, economic, and environmentally friendly method for obtaining durable and sustainable concrete.