Effect of old attached mortar on the creep of recycled aggregate concrete

This paper first presents an experimental study on the shrinkage and creep behaviour of recycled aggregate concrete (RAC) with different recycled coarse aggregate (RCA) replacement percentages (i.e. 0 %, 33 %, 66 %, 100 %). The experimental results reveal that increasing the RCA replacement percentage can increase the shrinkage and creep of RAC. A numerical method for creep behaviour with old adhering mortar is also proposed by analysing the influence mechanism of creep and the volume content of old adhering mortar on the creep of RAC. It is found that the RAC creep is significantly influenced by old adhering mortar properties and its volume content. Finally, a numerical model of RAC creep is established by considering the influence of mechanical properties and the creep behaviour of old adhering mortar. It is proved that this model can calculate the creep of RAC.