ICEBs stabilised with alkali-activated fly ash as a renewed approach for green building: Exploitation of the masonry mechanical performance

The demand for building materials and techniques with reduced environmental impact has been increasing in the last few years. Thus, efforts have been taken to include alternative raw materials with reduced extraction impacts and low embodied energy in their production, namely natural materials and industrial by-products with low or no processing needs. Nevertheless, the lack of technical knowledge about this type of materials leads to issues related with its safety, quality and durability. The work presented in this paper intends to be a contribution on this topic. Thus, an experimental program was carried out to evaluate the mechanical performance of interlocking compressed earth blocks (ICEBs) stabilised with activated alkali fly ash. The main objective of the experimental program was to assess the possibility of further exploiting the mechanical performance of the original dry-stack masonry system, by means of the use of mortared joints. Two alkali-activated binder based earth mortars were used for this purpose, and the results showed that a substantial mechanical improvement is obtained in terms of compression and shear behaviour of the respective masonry.This work is financed by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by Portuguese funds through FCT - Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633. The support from grant SFRH/BPD/97082/2013 is also acknowledged. The authors wish to express their gratitude to Eng. Jorge Henriques, on behalf of the company PEGOP - Energia Electrica SA, for providing the fly ash, and to Eng. Miguel Rodrigues, on behalf of the company CJR GROUP, for providing the soil