Use of concrete dust as a partial cement replacement

摘要

The paper examines the possibilities of using concrete dust as a partial replacement of cement binder. This dust was obtained as a by-product during the crushing of recycled concrete and therefore it is a raw material whose composition is directly dependent on the type and quality of the recycled material. The main motivation of this research was the effort to use this by-product and while contributing to reducing the environmental impact of cement production. In this research, cement was replaced with concrete dust from 0 to 50% to the cement content and after 28 days tested its compressive strength. Experiments have shown a negative effect when using concrete dust as a cement replacement. Primarily it was a high decrease in compressive strength, which was caused not only by cement replacement, but also by presence of organic substances in dust. This then resulted in foaming of the fresh mixture and subsequently a higher loss of strength. Thus, only a limited amount of concrete dust can be added to the concrete, for example to optimization of particle size distribution.