Proposal of New Natural Hydraulic Lime-Based Mortars for the Conservation of Historical Buildings

NHL mortars are known to be compatible materials for the conservation of architectural heritage. To improve their properties with regard salt resistance and lower carbon footprint, NHL-based inhibitor agents were studied different formulations produced: (MSs), composed natural hydraulic lime; sand cocciopesto (MSCs), in which NHL, brick powder admixed two products, diethylenetriaminapenta chitosan, concentrations. The mortar performance was tested against freeze–thaw crystallization through immersion–drying cycles a 14% sodium sulfate solution. results highlighted that addition effective increasing resistance, but increased water intake during tests. use DTPMP produced less thixotropic decreased uptake, worsened hardened mortars. Chitosan allowed good workability fresh mortar; its uptake similar reference slightly resistance. In samples, both additives reduced weight variation tests; meanwhile, lime final cycles.