Research of Mortar Containing Phosphorous Slag and Calcium Carbonate Nanoparticles
Ground phosphorous slag (PS) has not been widely used in construction due to its negative effects on the early-age performances of cementitious materials. The effects of calcium carbonate nanoparticles (NC) on strength development of mortar containing high content of PS were investigated at different curing ages. The NC was incorporated at 2% as partial mass replacements for binder. Hydration products and microstructure characterization was examined by X-ray diffraction (XRD), differential thermal gravity (DTG), thermogravimetric (TG), and scanning electron microscopy (SEM) analysis. Test results showed that NC improved both flexural and compressive strength of mortar containing high content of PS at 7, 28, 56, and 90 days. XRD, DTG-TG, and SEM analysis confirmed the filling effect of NC. Furthermore, the formation of the carboaluminate even at later age also improved the microstructure of mortar, which created a denser microstructure.