Resistance of limestone mortars with quaternary binders to sulfuric acid solution

The synergistic action of three mineral admixtures simultaneously incorporated in cement has a positive effect concerning the durability of limestone mortars. Tests were carried out on limestone mortars made from five quaternary binders (ordinary Portland cement and OPC blended simultaneously with limestone filler, blast furnaces slag and natural pozzolana). The purpose of this investigation was to identify the resistance of five different mortar mixtures to sulfuric acid solutions. The changes in weight loss and compressive strength values measured at 30, 60, 90, 120 and 180 days for each acid solution were studied. The pH variation of the sulfuric acid solution has been monitored during the tests and several phases are determined by XRD.

► Limestone mortars present an increase in resistance to sulfuric acid attack.
► Weight loss of mortars with mineral additions was minimal compared to the control.
► Hydration kinetics of slag and pozzolana can be accelerated by limestone filler.
► Mineral additions decrease the total porosity of mortars and reduce the permeability.