Effect of nano-SiO2 and curing temperature on the mechanical properties and hydration characteristics of cement systems containing a high volume of fly ash
In the search for an effective way of increasing the early strength of cement systems containing a high volume of fly ash (CHVFA), nano-silica (NS) was used in the CHVFA systems with two curing modes: standard curing (20 ± 2 °C, RH ≥ 95 %) for 3 days and steam curing (65 ± 2 °C, RH ≥ 95 %) for 12 h and then standard curing for 60 h. The effect of NS and curing temperature on the hydration of cement and fly ash and on the pore structure of the paste were studied in the search for the underlying mechanism.
1 Introduction
Chinese cement output has ranked first in the world continuously for 32 years, accounting for over half of the global total with 2,402,950,000 t in 2016 alone [1]. More and more attention has therefore been given to the application of supplementary cementitious materials (SCMs) that could partially replace cement. As a coal-fired country, coal is the main source of energy in China at present and will be for a fairly long period. Fly ash (FA) is the inevitable product of coal-fired power generation and every 4 t of coal consumption produces 1 t of FA. In 2015 alone it is estimated...