Use of recycled polymers in mortars and concretes

This article covers the most important methods developed to date for lightening cement-based construction materials (concretes, mortars), including the latest advances in recycling waste polymers incorporated in the cementitious binders of construction materials.

Traditionally, mortar or concrete can be lightened by including air, or by adding lightweight materials such as clays, perlite and expanded vermiculite. Other methods involve recycling products such as glass, cork and paper, and adding them in various ways to building materials such as concrete or mortar. These recycled materials then replace aggregates or filler/fine additions to improve mortar properties, whether in the fresh state (water retention, workability, rheology) or in the hardened state (thermal stability, mechanical strength, water absorption, water vapor permeability, acoustic properties).

In addition, lightweight mortars and concretes can be produced by replacing traditional lightweight aggregates with lightweight polymer aggregates, partially or completely depending on their density and mechanical strength, in order to reduce the problem of solid waste disposal, energy consumption and environmental pollution. Many alternative materials are being studied in this field, including expanded polystyrene, polyethylene terephthalate, polyethyl vinyl acetate and polyurethane.

The development of sustainable construction is one of the reasons why synergy is sought between conventional and polymer-based building materials. Improved knowledge of material behavior, particularly in the field of mixing, and a better understanding of curing processes have led to a significant increase in the use of these materials.