Due to the considerable amount of waste plastics and polymers that are produced annually,
the introduction of these waste products in construction materials is becoming a recurrent solution
to recycle them. Among polymers, polyamide represents an important proportion of polymer
waste. In this study, sustainable and lightweight mortars were designed and elaborated, substituting
the aggregates by polyamide powder waste. Mortars were produced with various dosages of
cement/aggregates, and the polyamide substitutions were 25, 50, 75, and 100% of the aggregates.
The aim of this paper is to determine the density and the compressive strength of the manufactured
mortars to observe the feasibility for being employed as masonry or rendering and plastering mortars.
Results showed that with increasing polymer substitution, lower densities were achieved, ranging
from 1850 to 790 kg/m3
in modified mortars. Mortars with densities below 1300 kg/m3 are cataloged
as lightweight mortars. Furthermore, compressive strength also decreased with more polyamide
substitution. Obtained values in recycled mortars were between 15.77 and 2.10 MPa, but the majority
of the values (eight out of 12) were over 5 MPa. Additionally, an economic evaluation was performed,
and it was observed that the use of waste polyamide implies an important cost reduction, apart from
the advantage of not having to manage this waste material. Consequently, not only the mechanical
properties of the new recycled materials were verified as well as its economic viability.
