Title:
Effect of Limestone on Electrical Properties of Cementitious Systems (Prepublished)
Author(s):
Jason Weiss, O. Burkan Isgor, and Keshav Bharadwaj
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
durability; electrical resistivity; formation factor; limestone; porosity; portland limestone cement
DOI:
10.14359/51749381
Date:
12/11/2025
Abstract:
The composition of OPC changed in North America with the addition of ground limestone in 2004 (since the adoption of ASTM C150-04a), which reacts to form carboaluminate hydration products. This paper discusses the potential influence of limestone addition on porosity, pore connectivity, formation factor, and electrical properties of cementitious systems. The carboaluminate reaction products can result in a system with limestone that has an equivalent water-to-powder ratio (w/p) that is approximately 0.07 lower than the system without limestone (occurring at the minimum porosity). When reactive alumina is added to the system, a greater amount of limestone reacts, and a reduction in porosity occurs. The carboaluminate phases impact the transport properties of mixtures to a greater extent for mixtures with moderately low w/p and aluminous SCMs. This has implications on standards and specifications, which are based on historic research and testing using cements not containing limestone, and therefore would have a higher porosity and lower formation factor than cements manufactured in the US after approximately 2004 at the same w/p.