Durability of limestone mortars based on quaternary binders subjected to sulfuric acid using drying

Durability of limestone mortars based on quaternary binders subjected to sulfuric acid using drying–immersion cycles

Makhloufi, Z. / Bouziani, T. / Hadjoudja, M. / Bederina, M.

Highlights • The quaternary binders has a positive effect vis-a-vis the durability of limestone mortars. • The limestone filler, blast furnace slag and natural pozzolana in limestone mortars has a benefic effect. • The performances of the limestone mortars with additions are better than that of the control mortar in sulfuric acid. • The weight loss, strength loss and pH are the quantification parameters of durability. • Seven drying–immersion and heating–cooling cycles accelerate the attack of mortars.

Abstract The aim of this work is to produce limestone mortars with blended-cement by substituting partially the clinker by three mineral additions. Namely; the limestone filler, the blast furnace slag and the natural pozzolana combined simultaneously to the cement for rates of 30%, 10% and 10% by turn. The mortar specimens were immersed in sulfuric acid solutions, and subjected to two protocols of attack. The first is slow; it is a continuous immersion. Specimens are exposed to 3% solution of sulfuric acid at 23±1°C. The second protocol is accelerated, and consists to subject the mortar samples to 7 drying–immersion and heating–cooling cycles, followed by a continuous immersion up to 180days. The drying is done at 60°C and the exposure in lime water and 5% sulfuric acid solution at 23±1°C. In this study the quantification parameters of durability of mortars are the weight loss and the compressive strength loss. The follow-up (the monitoring) of pH of the exposure solutions was carried out until end of the tests. The synergistic action of the quaternary binders has a positive effect vis-a-vis the durability of limestone mortars immersed in sulfuric acid solution and the performances of the limestone mortars with quaternary binders are better than that of the control mortar.