Title:
Physico-Chemical Characterization of Ground Bottom Ashes and Fluidized Bed Combustion Ashes and Evaluation of their Performance in Concrete Mixtures
Author(s):
Raikhan Tokpatayeva
Publication:
Web Session
Volume:
ws_S23_RaikhanTokpatayeva.PDF
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
4/2/2023
Abstract:
The diminishing supply of traditional fly ashes opens up potential for utilization of alternative types of supplementary cementitious materials (SCMs), such as ground bottom ashes (GBAs) and fluidized bed combustion ashes (FBCAs). This talk will present the results of a comprehensive study involving 3 GBAs and 2 FBCAs, including evaluation of such characteristics as chemical and mineralogical composition, particle size distribution, LOI and grain morphology. The pozzolanic reactivity of these materials was assessed using the R3 test. Moreover, reactivity of both types of these ashes in cementitious systems was evaluated on pastes with various levels of replacement of cement by these alternative SCMs. The evaluation involved quantification of the heat of hydration and the Ca(OH)2 consumption capacity. In addition, mortar samples with different replacement levels of cement by these ashes were tested for workability, setting time and compressive strength. The least reactive ash from each of these two groups of materials was chosen for evaluation of mechanical (compressive and flexural strength) and transport (water absorption, formation factor and freezable water amount) properties in concrete specimens.