Beneficiated ponded fly ash for concretes with high volume mineral additions

Nikolai Zaichenko,Liudmila Zaichenko,Irina Petrik,V.V Belov

doi:10.1051/matecconf/202031507006

Abstract

The article presents the investigation results of effect of beneficiated ponded fly ash on the properties of cement pastes and concretes with high-level replacement of Portland cement. To improve the characteristics of ponded fly ash meeting technical requirements for replacing cement in concrete the triboelectrostatic beneficiation technology has been elaborated. This technology can produce low-carbon ash product (LOI = 2.52 % in this study) for the high replacing level of cement (45 %) in concretes. The beneficiated ponded fly ash has an improved granulometric and phase composition, a decreased content of unburned carbon that accelerates the hydration process of cement, increases the rheological properties of cement paste and the ability of air-entraining admixture to hold the required involved air. In a combination with the nanostructured-carbon-based plasticizing admixture the beneficiated ponded fly ash exhibits high rate of strength increase when is used in high-volume fly ash concretes.

Highlights

The article presents the investigation results of effect of beneficiated ponded fly ash on the properties of cement pastes and concretes with high-level replacement of Portland cement
Triboelectrostatic beneficiation of fly ash with high-unburned carbon content can produce low-carbon ash products having value as mineral additions and meeting technical requirements for replacing cement in concrete [18]. This effect is of paramount significance when the beneficiated fly ash will be used in concretes with high volume of mineral additions in particular high-volume fly ash concrete (HVFAC) which contains normally more than 50 % fly ash by mass of total cementitious materials [9]
The aim and the objectives of this study are the following: i) to investigate the properties of ponded fly ash treated in the triboelectrostatic separator, ii) to determine the properties of HVFAC with the nanostructured-carbon-based plasticizing admixture and the ponded fly ash beneficiated by triboelectrostatic separation technique

Summary

Introduction

The article presents the investigation results of effect of beneficiated ponded fly ash on the properties of cement pastes and concretes with high-level replacement of Portland cement. To improve the characteristics of ponded fly ash meeting technical requirements for replacing cement in concrete the triboelectrostatic beneficiation technology has been elaborated This technology can produce low-carbon ash product (LOI = 2.52 % in this study) for the high replacing level of cement (45 %) in concretes. Triboelectrostatic beneficiation of fly ash with high-unburned carbon content can produce low-carbon ash products having value as mineral additions and meeting technical requirements for replacing cement in concrete [18]. The aim and the objectives of this study are the following: i) to investigate the properties of ponded fly ash treated in the triboelectrostatic separator, ii) to determine the properties of HVFAC with the nanostructured-carbon-based plasticizing admixture and the ponded fly ash beneficiated by triboelectrostatic separation technique

Objectives

Methods

Results

Conclusion