Mortar with sand from crushing of construction waste - Assessment of physical and mechanical characteristics

ABSTRACT Concern to the environment, due to the large amount of construction waste that is improperly disposed, encouraged the processing of these with the intention of returning them to the productive system. Studies to intensify the reuse of construction waste have intensified recently, developing standards for the production, evaluation and use of recycled aggregates, for which consumption is still incipient. For the development of the work, the characteristics of the recycled and natural aggregates were determined, including fine content. Two types of mortars were developed, one hydraulic and the other mixed. The recycled aggregate was used to replace the natural aggregate, in the proportions of 30% and 60%, for both types of mortar. The characteristics of the mortars in the fresh and hardened states were determined and the mortars were classified according to the specification standard for laying and coating mortars. The correlation between the fines contents of the mortar and the characteristics in the plastic and hardened states was verified for most of the observed characteristics. In the plastic state, the increase in the percentage of substitution of natural aggregate by the recycled produced a specific mass reduction of the order of 4% for both types of mortar, and the water retention capacity presented an inverse behavior, mixed mortars presented better results in this aspect. In the hardened state, the tensile and compressive strengths had lower results due to the increase in the substitution of the natural aggregate by recycling. The hydraulic mortar presented better performance than the mixed mortar when classified according to NBR13281. (AU)