Title:
The Influence of Accelerating Admixtures on the Electrical Resistivity of Cement Pasts
Author(s):
Montanari
Publication:
Web Session
Volume:
ws_F23_Montanari.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/29/2023
Abstract:
Electrical resistivity is a property that has been extensively studied by researchers and practitioners of the construction industry as a way to quickly assess the transport properties in cement-based materials. Electrical resistivity is directly related to the bulk diffusion coefficient through the NernstEinstein equation, and it is affected, among other factors, by the conductivity of the solution filling the pores of the cementitious matrix. The pore solution conductivity can be influenced by many factors, such as the water-to-cementitious ratio of the system, the type and replacement levels of supplementary cementitious materials, the degree of reaction of the cementitious materials and by the presence of specific admixtures. Accelerating admixtures are included in the group of admixtures that are known to affect the pore solution conductivity. However, limited data are currently available on the short and long-term effects that these admixtures have on both the pore solution and on the microstructure of the systems they are part of. This study aims to better understand the magnitude the pore solution is influenced by a series of accelerating admixtures, while monitoring changes in porosity and degree of hydration of the cement-based systems. The data show that the influence of the accelerating admixtures on the pore solution conductivity decreases over time. Moreover, accelerators are shown to have a measurable impact on the porosity of the systems, when accounting for the degree of hydration of the cement. The data show that even in the presence of accelerators, resistivity still displays a close relation-ship to microstructural features of the cement-based systems under study.