Aya Hanfay Reda Hanfy Mohamed

H. A. Abdel-Gawwad; E. E. Hekal; H. El-Didamony; F. S. Hashem

01/12/2018

Non-Portland cement or alkali-activated slag is regarded as non-friendly for users, due to the corrosive nature of alkaline solution. This negatively affects the mass production and commercial viability of this cement. In this work, user- and eco-friendly one-part non-Portland cement (NPC) was prepared by blending ground-granulated blast-furnace slag (GGBFS) with stable dry activator (SDA). SDA was synthesized by mixing two moles of NaOH with one mole of MgCO3 or dolomite, followed by drying and pulverizing to a fixed particle size (namely, SDA-M and SDA-D, respectively). The Mg source was chosen to prepare active magnesia with no firing. So, this process was considered as eco-friendly method for this purpose. Ordinary Portland cement (OPC) was used for comparison. The SDA-M content plays a circular role on the reduction of drying shrinkage of one-part NPC. The SDA-M has a potential impact on the compressive strength development of one-part NPC compared to SDA-D. NPC containing 12 mass% SDA-M (NPC-12) gave compressive strength values superior to those of OPC at all curing ages, suggesting that the NPC-12 can be beneficially used as an alternative to OPC as confirmed by X-ray diffraction (XRD), thermogravimetric analysis (TGA/DTG), and scanning electron microscopy (SEM).