Plaster is a construction material widely used for the production of prefabricated parts in building construction due to its high capacity for hygrothermal regulation, its good mechanical performance, and its fireproof nature, among other factors. Its historical use has been linked to ornamental elements, although more recent research is oriented towards the industrialisation of plaster composites and the design of prefabricated parts for false ceilings and interior partitions. In this work, the behaviour against water of four new plaster-based composite materials is studied, using additions of two types of super absorbent polymers (sodium polyacrylate and potassium polyacrylate) and a lightening material (vermiculite) in their manufacturing process. In addition, the transmission of water vapour through the samples was studied together with the water absorption capacity of the samples in order to check the suitability of the use of plaster-based materials exposed to these environments. The results of this study show that composites with the addition of super absorbent polymers as well as vermiculite significantly improve their water performance compared to traditional materials up to 7.3% water absorption with a minimal (13%) reduction in mechanical strength compared to current materials with similar additions. In this sense, a plaster material is obtained with wide possibilities of application in the construction sector that favours the development of sustainable and quality buildings, in line with Goal 9 for Sustainable Development included in the 2030 Agenda.

The building sector is facing the challenge of transitioning to a more industrialized construction approach and is thus promoting the development of new materials that enable the production of lighter prefabricated products with enhanced thermal performance. This study conducts the physicochemical and mechanical characterization of a new plaster material intended for application in the building sector. The plaster material developed contains potassium polyacrylate and perlite in its composition and has been reinforced with wood, glass and polypropylene fibers to improve its physical and mechanical properties. The results demonstrate that the combined incorporation of potassium polyacrylate and expanded perlite leads to a decrease in density and thermal conductivity by 10.5% and 47%, respectively, compared to traditional plasters. In addition, the incorporation of reinforcement fibers in the plaster matrix, particularly glass fiber, improves the mechanical strength of the new material. The plaster composite developed for this research offers lightweight characteristics and improves the energy efficiency of the construction systems into which it can be integrated and is designed for use in prefabricated panels and plates especially. This progress represents a step towards more efficient industrialized construction.