Microstructural Investigation of High-Volume Fly Ash Composites Containing Nano-Calcium Silicate Hydrate Crystals

This paper reports on the effect of addition nano-calcium silicate hydrate (nano-CSH) seeds early-age strength development and microstructural evolution concrete containing high-volume fly ash (HVFA). Cement replacement levels 60% 70% are considered. For each levels, 0.5%, 1%, 1.5% mass (FA) replaced with nano-CSH crystals. The compressive was tested at ages 1, 3, 7, 14, 28 days. Microstructural investigations involve thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). results show that 1% in HVFA60% HVFA70%, respectively, can effectively facilitate formation hydration products Ca(OH)2 C-S-H as well increase rate reaction gain early ages. It found dosages is a critical parameter achieving desired properties.