Mechanical performance and autogenous and drying shrinkage of MgO-based recycled aggregate high-performance concrete

The high strength and durability of high-performance concrete (HPC) may be significantly reduced by shrinkage cracking. use reactive magnesium oxide (MgO) can reduce cement-based materials due to its expansive properties. This study intends analyse the validity MgO as shrinkage-reducing agent in recycled aggregate HPC. To do so, ten HPC mixes with 0%, 25%, 100% both early-age (7-days air curing) matured (6-month RA were produced. In half mixes, 10% ordinary Portland cement was replaced MgO. slightly worsened mechanical behaviour HPC, especially when combined large amounts RA. On other hand, expansion fully offset autogenous total around 20–40%. Water storage RA, deferred release over time, produced a more efficient hydration MgO, which turn led further reduction shrinkage. However, increase drying caused greater than this decrease so higher content lower adding Thus, compensated because above 35% 42% Therefore, despite suitability effectiveness increasing