How do recycled concrete aggregates modify the self-healing properties?
The recycled concrete mixtures were designed by replacing natural aggregates with 0%, 30%, and 100% of recycled concrete gravel (RG) and 30% of recycled concrete sand (RS).
Good potential at long term
The water to equivalent binder ratio was kept constant and recycled concrete aggregates were initially at saturated surface dried state. At long term, the maximum variation of drying shrinkage magnitude due to recycled concrete gravels did not exceed 15%. The correlation between drying shrinkage and mass-loss through “drying depth” concept showed that recycled concrete aggregates are affected by drying as soon as concrete is exposed to desiccation. A good correlation between 1-day compressive strength and 18-month carbonation depth was observed. The recycled concrete aggregates presented a good potential for self-healing as the relative recovery of cracks reached up to 60%.
The study is published in: Cement and Concrete Composites, Volume 86, February 2018.