Effect of activator type in a slag mortar mixed with alkali-activated limestone

Abstract

Introduction− Alkaline activated slag has been a fundamen-tal base in the development of new cements with mechanical and physicochemical properties which in some cases have been better than those of traditional cement, this type of industrial products leads to the study of alternative construction materi-als.Objective−To study the effect of different types of alkaline activators, limestone addition and temperature changes on the physical-mechanical properties of alkaline-activated slag-based mortars.Methodology−A physicochemical analysis of the character-istics of the raw materials is carried out by means of tests of SEM, XRF, XRD. Preliminary tests were developed to de-termine the optimal dosage of the activators used, to later elaborate the mortars object of the study and to evaluate their mechanical property. The study is developed for three alka-line solutions Na2SiO3/NaOH (SH), Na2SiO3/Na2CO3 (SC) and Na2SiO3 (SS), as well as for two curing temperatures at room temperature (23ºC) and 60ºC.Results−As a result, the activator with the best performance was obtained, which was the Na2SiO3/NaOH (SH) reaching a resistance of 35.3 MPa.Conclusions−According to the results, the mortars that pre-sented better behavior were those submitted to temperatures of 60°C and a longer curing time increasing their resistance properties.

Keywords

• alkaline solution
• limestone addition
• sem (scan-ning electron microscopy)
• xrf (x-ray fluorescence)
• xrd (x-ray diffraction
• compression resistance
• mortars
• slag
• optimum dosage