Next: Electrical conductivity and Up: Main Previous: Main

Introduction

The dc electrical conductivity of cement paste, σ, is an important transport parameter, and can be used as a probe of microstructural development [1]. Also, of particular practical significance, ionic diffusivities can be obtained from the Nernst-Einstein relation [2] by using the relative conductivity σ / σ_o, where σ_o is the pore fluid conductivity. Scientifically sound quantitative relationships between microstructure and σ / σ_o have never been made. This is because of both the lack of an adequate theory, and the lack of a program of careful, systematic measurements. This paper presents a preliminary comparison between simultaneous experimental measurements of σ and σ_o using impedance spectroscopy, and computer simulation predictions of σ / σ_o.