Analysis of the properties of masonry mortars made with recycled fine aggregates for use as a new building material in Cuba

Abstract

This paper details the research work carried out on masonry mortars produced employing recycled aggregates in 100% substitution for natural sand aggregates. The main objective of the work being the validation of the resulting recycled aggregate mortar for use as a new construction material in Cuba. The recycled aggregates were acquired from the crushing of demolition material obtained from four different houses of distinct construction types. The work was carried out in two experimental stages. In stage 1, mortars with different percentages of recycled aggregates were produced and analysed. The analysis was carried out in order to achieve the optimal mix dosage, while employing the largest usable volume of recycled aggregates and in compliance with the functional requirements established by Cuban regulations. In stage 2, all mortars were produced employing the defined optimal mix proportion The fresh state properties (water retentivity) and hardened state (flexural, compression and bond strengths and capillary absorption capacity) were evaluated in the mortars produced with the other three mixed recycled aggregates of different compositions.  It was concluded that the mortars produced with recycled aggregates needed less filler than that of the control mortar in order to obtain adequate properties in their fresh state. However, these recycled aggregate mortars obtained lower mechanical properties and higher capillary absorption that those of the control mortar. Nevertheless they were in compliance with the minimum requirements established in the Cuban regulation.