Commercial NHL-containing mortars for the preservation of historical architecture. Part 1: Compositional and mechanical characterisation

► NHL-based binders and ready mixed mortars for the conservation of historic masonries. ► Compositional, microstructural, mechanical features studied according to compatibility criteria. ► Evaluation of the influence of different substrate and curing conditions on the final microstructure. ► NHL class assignment data not suitable for describing the final mechanical behaviour of the mortars. ► Mortars intended for similar purposes show extremely heterogeneous characteristics.