A comparative analysis of the properties of recycled and natural aggregate in masonry mortars

Masonry mortar is one of the most manufactured and used building materials in Havana, Cuba. The lack of natural sand and the great quantity of demolition waste that exists in the city makes one realize the potential benefits of the use of this abundant waste material to create recycled fine aggregates for their use in the production of masonry mortars. In this research work three types of fine mixed aggregate were used. These aggregates, which were the result of the crushing of demolition waste proceeding from the three typical types of buildings in Havana, were used as a substitute for 100% of the natural sand used in the production of masonry mortar. the lack of natural fine aggregates Cuban regulations allow for the use of fillers in the manufacture of masonry mortars, in order to correct this defect. Three different types of filler were evaluated for masonry mortar production; lime hydrate (commonly used in Havana) white slag filler (a by-product of steel manufacturing) and limestone filler (natural). The masonry mortars were made using either 100% natural or recycled aggregates with any of type of filler, they were tested after a 28 days period of curing in a humidity room and their physical, mechanical and durability properties were analyzed. The results obtained from the tests proved that the masonry mortars manufactured with a combination of recycled fine aggregates and any of the three types of filler mentioned not only complied with the requirements established in the Cuban regulation, but in the majority of cases the properties obtained from these mortars were better than those mortars made with natural aggregate.