Mercury intrusion porosimetry in concrete technology: tips in measurement,pore structure parameter acquisition and application

Mercury intrusion porosimetry (MIP) has been widely used to investigate the pore structure of cement based materials for many years. The purpose of this paper is to present views of how to make MIP results of similar materials from different research institutes compatible and how to use MIP results in modeling. Factors that influence MIP results are analyzed comprehensively considering characteristics of cement based materials, and recommendations corresponding to these factors are illustrated. According to these recommendations, when specific tests are unavailable, mercury surface tension of 480 mM/m and mercury-solid contact angle of 130° may be used in theoretical calculations of pore size; sampling by either sawing or core-drilling, maximum value of the minimum sample dimension of 5 mm, and solvent drying are recommended for sample preparation; and staged operation mode which set appropriate equilibrium time is recommended for MIP measurements of cement based materials. From a MIP result, the methods which are necessary to be unified to determine pore structure parameters are discussed. Besides, it is shown that sometimes pore structure parameters should be used carefully in physical models by considering their physical or statistical meanings.