“…As aforementioned by other studies (Dal Pozzo et al, 2019;Duxson et al, 2007b;McLellan et al, 2011), geopolymer samples present a greater sustainability compared with PC counterparts, and some studies even indicated that the energy consumed and carbon footprints emitted by geopolymer production were significantly lower in comparison with those associated with PC sample preparation (Hassan et al, 2019;Sandanayake et al, 2018;Taylor, 2013), which were mainly associated with the avoidance of limestone calcination (Dal Pozzo et al, 2019), however, (Ma et al, 2018;Ouellet-Plamondon and Habert, 2015) also indicated that not all alkali-activated binders presented a lower global warming potential (GWP) in comparison with blended cements via Feret equation, and they indicated that one-part geopolymer seemed to be a more promising binder concerning sustainability. Meanwhile, compared with the precursors, the production of alkali used in the preparation of samples was still an energyintensive process, therefore, (Dal Pozzo et al, 2019) suggested the use of sustainable energy supplies such as hydrothermal route in its production, whereas (Salas et al, 2018) indicated that using NaOH in geopolymer concrete, which was produced from solar salt, would led to a great reduction in the overall environmental impacts related with sample preparation. Recently, reactive magnesia has been used as the activator in alkali-activated binders (Jin et al, 2013;Jin et al, 2014) due to the lower environmental impacts associated with its production Unluer, 2016, 2017), and the results also indicated that use of reactive magnesia could alleviate the shrinkage of samples due to its expansion as a result of magnesia hydration (Jin et al, 2013;Jin et al, 2014).…”