Abrasion Resistance of Cement Paste with Granulated Blast Furnace Slag and Its Relations to Microhardness and Microstructure

Abstract

The abrasion resistance of cement pastes with 30 wt%, 40 wt% and 50 wt% granulated blast furnace slag (GBFS), and its relations to microhardness and microstructure like hydration products and pore structure were studied. Results indicated that GBFS decreased the abrasion resistance of paste, and among the pastes with GBFS, the paste with 40 wt% GBFS showed the highest abrasion resistance. The microhardness of GBFS was lower than that of the cement, and the microhardness of the hydration products in paste with GBFS was also lower than that of the hydration products in paste without GBFS, so that the abrasion resistance of paste decreased when GBFS was incorporated. The reason for the decrease of microhardness of pastes with GBFS was that the contents of Ca(OH)₂ in pastes with GBFS was significantly lower than that in the paste without GBFS, while large amounts of calcium aluminate hydrates and hydrotalcite-like phases (HT) in pastes with GBFS were generated. Furthermore, among the pastes with GBFS, the paste with 40 wt% GBFS showed the lowest porosity which was the main reason for its highest abrasion resistance.

Keywords

paste / abrasion resistance / granulated blast furnace slag / microhardness / microstructure