Influence of Chemical Additives on the Properties of Composite Materials Based on Fine-Dispersed High-Calcium Fly Ash

Abstract

Composite materials (CM) were obtained on the basis of fine- dispersed high-calcium fly ash (HCFA), selected from the 4th field of electrostatic precipitators of Krasnoyarsk TPP-2, with the addition of Melflux 5581F superplasticizer at the water: binder ratio W/B = 0.25. The influence of the concentration of superplasticizer in the range 0.06-0.6 wt. % on the strength properties of composite materials was studied. The effect of the addition of sodium sulfate as an accelerator of hydration hardening and additives-retarders of sodium phosphate, sodium tetraborate and citric acid, were studied. The optimal concentration of superplasticizer was established (0.3 wt. %). It was determined that sodium sulfate helps to improve the strength of CM, and the addition of sodium tetraborate and citric acid can effectively regulate the setting time