When an accelerator that is used in shotcrete reacts on cement, it quickly sets upon early hydration. Use of cold-weather concrete prevents concrete damage from freezing. There is difficulty securing workability, however, since early hydration makes it react rapidly. In this study, a tablet that is used in pharmaceuticals was made of an aluminate-based accelerator and is discussed in terms of its mortar setting time and flow test result. Also, the rate and progress of its hydration were evaluated by analyzing the X-ray diffraction (XRD) and scanning electron microscopy (SEM) results. As a result, in the sample that included both the tablet and the aluminate-based accelerator, hydrates such as calcium aluminate hydrate (C-A-H) and calcium hydroxide [Ca(OH)2] were formed within similar times.

Keywords: Tablet, Aluminate-based accelerator, C-A-H, Early strength, Workability