Effect of water and alkali content on setting time of cement pastes with electric arc furnace dust (EAFD)

Abstract

This study was undertaken to provide additional information about the effects of varying water-binder ratio (0.30-0.55) and electric arc furnace dust (EAFD) content (up to 20%) on setting times of blended cements. A study about the influence of total alkali content on setting time of blended cement was also conducted as an attempt to identify an efficient pre-treatment system to solve the retardation influence of such dust on setting time. Results indicate that the use of low w/b ratio is effective in shortening the setting time of blended cements, limiting the setting time below 24 h in most of the analysed mixtures. Increasing the alkali content was also effective on shortening the setting time of blended pastes. Final setting time of pastes with 10% and 20% EAFD was less than 6 hours, and when the EAFD content was 5%, setting times was almost the same of the cement paste.