Durability of limestone mortars based on quaternary binders subjected to sulfuric acid using drying–immersion cycles Z. Makhloufi a,⇑ , T. Bouziani a , M. Hadjoudja b , M. Bederina a a Laboratory SREML, University of Laghouat, P.O. Box 37G, Laghouat 03000, Algeria b Laboratory LRGC University of Laghouat, P.O. Box 37G, Laghouat 03000, Algeria 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. article info Article history: Received 9 April 2014 Received in revised form 21 August 2014 Accepted 27 August 2014 Keywords: Crushed limestone sand Limestone filler Blast furnace slag Natural pozzolana quaternary binders Drying–immersion and heating–cooling cycles Sulfuric acid Weight loss Compressive strength loss pH 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 180 days. 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 mor- tars immersed in sulfuric acid solution and the performances of the limestone mortars with quaternary binders are better than that of the control mortar. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Over the past two decades, the use of mineral admixtures as partial substituent of Portland cement in concrete has become very popular because of their technological, economic, and environmen- tal advantages. The use of mineral additions such as limestone fill- ers, blast furnace slag and natural pozzolana improves the resistance of concrete to the attack of aggressive agents (sulfuric acid), because they reduce the presence of calcium hydroxide, which is the most vulnerable component to acid attacks [1–3]. The cements standards allow only the introduction of small quantities (less than 5%) of secondary components, in cements. Sev- eral studies have shown that, the presence of filler and aggregate limestones in the cementitious material increases its resistance to the sulfuric acid attacks [4,5]. The slag has several advantages in the manufacture of cement. First, it has a relatively constant chem- ical composition compared to fly ash, silica fume, natural pozzolana etc. In addition, it has other advantages such as, low heat of hydra- tion, resistance to acids and sulfates, better workability, and higher ultimate strength, [6–8]. The highest resistance to a solution of 0.5% of sulfuric acid was achieved by a binary mixture of binder compris- ing more, than 60% of granulated blast furnace slag [9]. However, Chang et al. have reported, recently, that binary binders of concrete prepared with 60% slag and ternary binders prepared with 56% of slag and 7% of silica fume had a lower yield (performance) than a mixture of 100% of Portland cement, when it is immersed in a solu- tion of 1% of sulfuric acid at a pH of 1.27 [4]. http://dx.doi.org/10.1016/j.conbuildmat.2014.08.086 0950-0618/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: z_makhloufi@yahoo.fr (Z. Makhloufi). Construction and Building Materials 71 (2014) 579–588 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat