Durability Performance of Concrete Containing CFBC Fly Ash and Coal-Fired Fly Ash

Abstract

This study presents an investigation into durability performance of concrete with various combinations of circulating fluidized bed combustion (CFBC) fly ash and coal-fired fly ash. All cylindrical specimens with the same binder content of 420 kg/m3 and water/binder ratio of 0.5 were cast and cured in the saturated limewater. Permeability test, sulfate attack resistance test, rapid chloride ion penetration test (RCPT) and carbonization test were performed. Test results demonstrate that the adding of CFBC fly ash and coal-fired fly ash would reduce the water permeability and chloride ions penetration, and increase the sulfate attack resistance, but an increase in carbonization depth. The carbonization depth increases with an increasing contents of CFBC fly ash and coal-fired fly ash. There exists a negative relationship between compressive strength and carbonization rate. Based on the test results, CFBC fly ash and coal-fired fly ash can be considered as cement replacement materials and employed in concrete.

Fly ash from fluidized bed combustion of peat and wood as a cement replacement material

“…FBCFA from wood combustion caused no significant decrease in sulfate attack resistance when the replacement rate was 40% or lower (Modolo et al (2018)). Chi and Huang (2014) showed that cement replacement by combination of PCC and FBCFA can increase the strength of the concrete specimen during the sulfate attack experiment. It should be noted, however, that the chemical composition of FBCFA (used by Chi and Huang, 2014) was totally different, consisting mainly of CaO and SO3, compared to ash used in the present study.…”