Geopolymers as strenghtening materials for Built Heritage

Conservation of historical stone and stone-like surfaces of built heritage has usually been performed with organic materials, such as polymers either for consolidation of decayed and fragile surfaces or to reassembling detached fragments by gluing. Moreover modern materials and devices have been used to strengthen those substrates in order to enhance even their mechanical properties. During time, the low compatibility of some of those repairing products with original artifacts turned out on a further degradation that needed to be addressed with time-consuming and expensive retreatments or structural retrofit. Taking into account the issues of compatibility and durability for a sustainable conservation of historical stone and stone-like surfaces, geopolimeric materials are under investigation in our laboratories to fulfill those requirements. During the past decades, geopolymer composites - "alkali activated" geopolymers - were deeply investigated as non-cement binding materials for different purposes. The tailored designed structural and chemical characteristics of these materials allow their use as building material, fire and/or heat-resistant coatings and also nuclear waste encapsulation. The present work aims to investigate the applicability of geopolymeric components as a matrix of composite materials for the structural retrofit of brick masonry. Prelimary results are reported regarding the formulation of geopolymer composites, their characterization and first mechanical tests performed on the Fiber Reinforced Geopolymer (FRGP) applied on soft mud bricks.