Lightweight sprayed materials for reinforcing and rehabilitating urban heritage buildings and structures

One of the most common options for reinforcing structural elements is spraying cementitious materials, which form an adhered layer on the reinforced structural element. Although this technique holds great potential for rehabilitation, its widespread and efficient use has limitations. MAPPU aims to improve existing knowledge of the material, technical, and structural calculation methods required to carry out reinforcements using a single sprayed layer that safely meets all the specified requirements.

The technological breakthrough that MAPPU has achieved in the sprayed reinforcement method is based on four key factors. First, the improvement of the materials used through the development of lightweight structural sprayed mixtures, with low permeability, compensated shrinkage, and more sustainable properties, which allow for easier application and enhanced reinforcement. Second, by developing structural calculation models that take into account the specific characteristics of the sprayed material (whether lightweight or of normal density), optimizing the design in terms of adhesion to reinforcements and creep (i.e., the increase in deformation of the sprayed layer under constant load, which over time leads to an increase in the load absorbed by the reinforced structure).

Third, through the improvement of quality control techniques used to assess the behavior of the sprayed material at the beginning of its lifespan. Finally, integrated durability models that allow for the design and analysis of the lifespan of the structure should be proposed, considering both the reinforcement and the existing structure.