Title: Mercury Porosimetry of Cement-Based Materials and Associated Correction Factors

Author(s): Raymond A. Cook and Kenneth C. Hover

Publication: Materials Journal

Volume: 90

Issue: 2

Appears on pages(s): 152-161

Keywords: concretes; durability;; mercury porosimetry; microstructure; permeability; porosity; strength; Materials Research

DOI: 10.14359/4011

Date: 3/1/1993

Abstract:
This paper briefly reviews the technique of mercury porosimetry, presents assumptions and corrections relevant to the application of mercury porosimetry to cement-based materials, and examines the impact of these corrections and assumptions on calculations based upon porosimetry data. A generalized form of the Washburn equation is given: corrections are given for machine expansion, differential mercury compression, sample compression, and hydrostatic pressure; and values appropriate for cement-based materials are given for contact angle, surface tension, and pore shape. Numerical relationships that predict strength, permeability, and durability on the basis of pore structure information are then given, and these equations are used to assess quantitatively the impact of different assumptions and corrections. It is shown that assumptions and corrections employed in processing porosimetry data have a significant effect on porosimetry results, affecting total porosity values, threshold pore size values, and curve shape. Different assumptions and corrections can, therefore, lead to significantly different predictions of strength, permeability, and durability. Thus, researchers should include details on the assumptions and corrections used when presenting porosimetry results to enable comparisons to other work.