Metakaolin as a precursor of materials for applications in Cultural Heritage: Geopolymer-based mortars with ornamental stone aggregates.

摘要: Abstract Potentialities and suitability of metakaolin-based geopolymers in Cultural Heritage have been explored. In particular, order to evaluate their possible use as restoration materials conservation historic manufactures, mortars prepared by adding aggregates Italian ornamental stones alkali-activated metakaolin with binder/sand ratio 1:1. To improve workability, geopolymer binders synthesized from sodium silicate solution water/solid weight ratios between 0.33 0.66 SiO 2 /Al O 3 Al /Na molar 3.70 1.04, respectively, characterized several techniques, including mechanical strength tests according UNI EN 196-1. All display good properties, compressive flexural values high 72 MPa 6 MPa, decreasing increasing ratio. The increase water formulation has little negative effect on the aluminosilicate gel development these materials. Mortars a homogeneous compact matrix, bonded (silicoaluminate aggregates) or interlocked (carbonate) aggregates. Their strengths fall masonry class M20 range. pore size distribution guarantees breathability adaptability substrate. final mimic original stones, aesthetic compatibility.