Carbonation process of commercial lime mortars vs cement-based mortars: Comparative analysis of textural differences, strength and durability

Department of Engineering Geology and Geotechnics, Budapest University of Technology and Economics, H-1111, Budapest, Muegyetem rkp. 3, Hungary

^* Corresponding author: torok.akos@emk.bme.hu

Abstract

The present study analyses 5 commercially available mortars (Italian, German and Hungarian brands) under various conditions such as dry, water-saturated and freeze-thaw. Laboratory tests assessed specimens' physical properties and carbonation process 28 days after casting using EN guidelines. The workability, density, ultrasonic pulse velocity, water uptake, and strength parameters were measured. The bulk density of the studied mortars was between 1514-1840 kg/m³, indicating the variations in composition and porosity, and it correlates well with the measured P-velocities of 1939 m/s to 2649 m/s. The compressive strength of cubic standard test specimens was between 1.8 and 8.4 MPa, suggesting different mineralization and carbonation processes, clearly marking the presence of the Portland cement phase. A large scatter of physical parameters and various durability marks water-saturated and freeze-thaw-affected mortars. Carbonation and curing conditions can cause significant parameter differences in lime-based mortars. CO₂ sequestration depends on mortar composition, textural and micro-fabric, and environmental conditions.