Microstructure, compressive strength, and permeability of Portland-condensed silica fume cement

摘要

This paper investigates at the effects of condensed silica fume (CSF), as a cement replacement material, on the properties of cement-based pastes and mortars. The compressive strength, microstructure, and electrical resistivity of Portland-CSF cement were determined. In this research, CSF was used to replace cement at 0-8 wt% to produce Portland-CSF cement pastes and mortars with water to binder ratio of 0.5 for all mixes. Experimental results showed that the compressive strength of the mix with CSF was significantly increased with added CSF content, especially for the mix with 8 wt% of CSF, which was found to have the highest compressive strength (114% higher than that of PC control mix). Moreover, the microstructure of the Portland-CSF paste revealed a good reaction, as evident from the covered phases on the CSF particles. In addition, the durability of the concrete, which was primarily determined by bulk resistivity analysis, showed that CSF incorporated with PC could be used to enhance the properties of plain concrete.