Comparative Study of Effects of Air-Entraining Plasticizing Admixture and Lime on Physical and Mechanical Properties of Masonry Mortars and Plasters

Abstract

This article presents research on selected physical and mechanical properties of cement-based plasters and masonry mortars with consistency-improving additives, namely, traditional hydrated lime and a plasticizing and aerating mixture (APA), which, in practice, is often considered to be a lime substitute. Comparative analysis of the properties of mortars with alternative additives—lime or APA—was carried out, taking into consideration possible effects of cement, as two types of Portland cement were used for the research. For fresh mortar, mixture consistency, air content, resistance to segregation, and water retention were determined. Tests on hardened mortars included tests of porosity and impermeability, depth of penetration of water under pressure, drying shrinkage, as well as compressive and bending strength, modulus of elasticity, and adhesion of mortars to the base. In addition, research has shown that cement–lime mortars and cement mortars with APA admixture of similar consistency in the fresh state are characterized by significantly different properties. The results show, in most of the features analyzed, more favorable properties of mortars with the use of traditional lime. For shrinkage only, the use of admixture turned out to be more advantageous.

Environmentally Friendly Masonry Mortar Blended with Fly Ash, Corn Cob Ash or Ceramic Waste Powder

“…This is why, despite the early stage of a pozzolanic reaction and poor mechanical properties, the adhesive strength of CWP-based mortars is on par with the strength of the reference specimens for each mixing ratio. This effect is consistent with previous research on this topic [56].…”