Mechanical properties of mortars with waste plastic as replacement of natural aggregate

The use of waste plastic from Waste Electrical and Electronic Equipment (WEEE) as a substitute for natural aggregate in cementitious materials is an increasingly relevant issue. In fact, this would allow to recycle plastics destined for landfills and to decrease the use of new natural resources. However, replacing sand with plastic tends to reduce the mechanical properties of mortars due to the different mechanical properties between the natural aggregate and the waste plastic and the poor interfacial compatibility between the plastic and the cement paste. This work used several strategies to improve the mechanical properties of mortars containing waste plastic. The addition of 1 % of superplasticizer coupled with a lower w/c ratio succeeds in restoring the mechanical properties to values equal to a standard mortar prepared with the natural aggregate, thus obtaining a material that can be used in the construction field.