Technical Evaluation of Construction Mortars with Various Lime Quantity Additions

Abstract

Construction mortars are materials for common use. The broad range of their usage results from their technical parameters and consequently from possibilities of various material and technological solutions. They can be used in various solutions both in existing objects as well as new-built ones. The history of using mortars reaches very old times. Lime as a binder was applied already about 3000 BC for building pyramids, decoration and finishing of building walls. Over time lime was added with pozzolan thanks to which the mixture gained better technical parameters. Currently, for design of mortar with necessary physical and strength properties it is needed proper component selection, their dosing and mixing. Essential role is played here by correct proportions and quality of components. Too low or high contents of particular components can significantly influence their technical properties. This article concerns the evaluation of influence for various quantities of hydrated lime (10, 20 and 30% in relation to cement amount) added to mortars on their basic technical parameters and microstructure defined with mercury porosimetry method. Microscopic tests were performed according to the Polish standards. They include evaluation of permeability, compression and flexural strength. During the microstructure tests the cumulative curve of pore volume in relation to their diameters was obtained. On its base the percentage contents of mezzo- and macropores was defined depending on type of mortar sample types. It was found that lime addition essentially influences technical parameters obtained.