Effect of activators, admixtures and temperature on the early hydration performance of desulfurization ash

Abstract

The methods of activators, active mineral admixtures and temperature were used to activate the pozzolanic and self-cementitious properties of desulfurization ash, as well as to compare and analyze the 7days and 28days compressive strengths of desulfurization ash mortar. Meanwhile, the early hydration process and hydrated products of desulfurization ash were analyzed with X-ray diffraction analysis (XRD), FT-IR spectra (FT-IR) and scanning electron microscopy (SEM). The research results show that different kinds of activators and active mineral admixtures can activate the early active of desulfurization ash, as follows, the first is quicklime, then sodium silicate, slag powder, triethanolamine, Na2SO4 and the last is silica. By the combination of organic chemical activators and inorganic mineral admixtures mentioned above, the 7days and 28days compressive strengths of desulfurization ash mortar can be up to 20MPa and 22.3MPa, respectively. The strength can still be raised by enhancing the proper curing temperature.