HYDRATION OF ALKALI-SLAG CEMENTS AT 150 DEGREES C

This paper deals with the strength development, pore structure and hydration products of alkali-blast furnace slag cement (ABSC) and alkali-phosphorus slag cement (APSC) at 150 degrees C, portland cement (PC) is used as control. The experimental results indicate that the ABSC and APSC pastes show a plateau in strength development after 1 day, and PC pastes reach a maximum strength at 1 day, then the strengths of APSC and ABSC pastes increase slightly and the strengths of PC pastes decrease noticeably. APSC pastes show the highest strength and the smallest porosities and PC pastes show the lowest strength and the largest porosities. Pore radii in APSC and ABSC pastes mainly are in the range 18 to 100 angstrom and pores in PC pastes mainly are larger pores with r greater than 100 angstrom. The hydration products of APSC are CSH(B) and tobermorite, CSH(B) and trace tobermorite for ABSC, and coarser crystalline C2SH(A) and Ca(OH)2 particles for PC after autoclaving for several days. (Author/TRRL) (Author/TRRL)