QUANTITATIVE EVALUATION OF SPATIAL MICROSTRUCTURE IN CEMENT PASTES BY SECOND-ORDER STEREOLOGY

摘要

Second-order stereology functions were used to quantitatively evaluate geometrical features of microstructure in hardened cement pastes with various water/cement ratios. The functions sensitively reflected changes in the microstructure with time. It was possible to understand the characteristics of microstructure intuitively in a sense of length. Continuity of large capillary pores was well characterized by the lineal-path function. Cross correlation function between cement and pores implies the presence of dense layer of hydration products around the unhydrated cement cores. Only the first-order parameters such as area fractions of phases have been used in the SEM-BSE image analysis for cement microstructure. However, it is found that the second-order functions also give useful information on the evolution of microstructure in cement pastes. Combination of first- and second-order stereology parameters could be a more sophisticated evaluation method in the SEM-BSE image analysis.