Valorization of crushed bricks in lime-based mortars

•The potential of brick waste recycling and its use in aerial lime-based mortars is investigated.•The incorporation of brick dust in lime mortars generated a pozzolanic reaction.•Brick dust improved the compressive strength.•Brick dust increased the hygric and hydric expansion of lime-based mortars. To preserve architectural heritage for future generations, restoration materials such as mortars should be compatible with the historic substrate. Pozzolanic mortars are a compromise solution between Portland cement-based mortars and aerial lime-based mortars. This paper investigates the recycling of brick waste in the Meknes region of Morocco to formulate pozzolanic mortars. Nine different mortars were made using aerial lime, sand and brick dust. They were characterized in terms of shrinkage, color, mechanical and hydric properties. The study revealed that Meknes brick dust exhibits a pozzolanic activity and reduces shrinkage. Moreover, it increases hydric and hygric expansion, enhances mechanical strength and affects the color of mortars. An appropriate recipe for restoration mortars could then be proposed to restore regional architectural heritages, depending on the properties of their historic substrates.