LAUSR

Abstract The characterisation of recycled fine mortars under frost action was highlighted in this study. Mortars with three different ratios of recycled cement (RC), namely (10%, 30% and 50%) along with a reference mortar with 0% RC were prepared and subjected to freeze–thaw (F–T) cycles without air-entraining agents. After 96 F–T cycles, the specimens did not reveal any macroscopic damage; however, changes were noticed at a microscopic level. The pore diameter increased and the size of the rehydrated cement products decreased, especially in the case of 30% and 50% RC mixes. In this experimental study, the physical (mass loss and dimensional variation) and mechanical (flexural strength and dynamic elastic modulus) behaviour of the recycled mortar revealed that the critical period of structural degradation occurred during the first 24 F–T cycles.