Study of the mortars employed by Antoni Gaudí at Casa Batlló / [Mireia Bosch Prat, Joan Olona Casas, Ana Belén Onecha Pérez, [et al.]]
En: Historic Mortars Conference. 7th Historic Mortars Conference (HMC 2025): 2nd-4th September, Padova : [Padova], 2025. p. 351-353
The architect Antoni Gaudí and his body of work have been subjects of extensive academic interest. However, the constructive aspects have been relatively underexplored, focusing on only a few specific elements. The renovation, designed and executed by Antoni Gaudí, of Casa Batlló (1904-1906) is one of his most highly classified works: UNESCO World Heritage Site (designated on July 15th of 2005). This recognition requires the highest standards of quality in the conservation and management of the building. Any intervention, no matter how minor, requires an in-depth understanding of the materials, elements, and systems to ensure their proper comprehension and to facilitate the application of the general restoration principles outlined in the Master Plan. Over the last decade, several maintenance, conservation, and reinstatement interventions have been carried out to restore original elements altered during the mid-20th century. These actions have provided a deeper understanding of the building and have enabled the characterisation of construction systems, ensuring the highest standards of rigour for interventions. Prior to the interventions, an extensive body of literature on Gaudi's work, including scientific articles, outreach publications, studies and doctoral theses containing relevant information, provided a solid foundation of knowledge. This review framework allowed delving deeper into the strategies employed by Antoni Gaudí at Casa Batlló. The period during which Antoni Gaudí carried out the renovation of Casa Batlló concurred with a time of transition and transformation of construction materials. The production of mortars and concretes was becoming a fully-fledged industry, and the use of lime as a binder was being increasingly supplanted by others with higher hydraulic properties and enhanced performances. From previous studies, it can be stated that mortars made with lime, natural cement, and Portland cement, across their different variants, coexisted on the market at that time. Gaudí sought to exploit the advantages, qualities, and specific properties he recognised in each of these mortars by applying them across multiple building elements, both in the interior and the exterior. Casa Batlló serves as an example that reflects the historical evolution of binders used for mortar production in Catalonia during the transition period between the 19th and 20th centuries. Although it cannot be confirmed with certainty whether the inauguration of the first Portland cement factory in Catalonia (Asland in Castellar de n'Hug, 1904), established through the patronage of Eusebi Güell i Bacigalupi, provided Gaudí's access to this new binder, it is well known that Gaudí was neither conventional nor one to miss opportunities to explore the innovations offered by emerging materials and techniques. It is therefore very likely that Gaudí also experimented with Portland cement at Casa Batlló. Indeed, this study found evidence that binders exhibiting a comparable hydraulicity were used during the renovation, which supports this hypothesis. This research aims to identify multiple mortars used during Antoni Gaudí's renovation of Casa Batlló and, once identified, to characterise the performance requirements as well as establish the techniques employed in their application.
