New approach of mercury intrusion porosimetry to evaluate the microstructure of cement-bases matrixes: Application on slag cement mortars

In this work, the experimental technique "Mercury Intrusion Porosimetry MIP", a characterization technique commonly used with success, is presented (sample preparation, experimental procedure, results). Usually the results of the said technique are mainly used for the microstructure characterization of cement-based matrixes. In order to better define the pore network characterization, a particular procedure has been tried: for each test, a double mercury intrusion is performed, allowing the measurement of the pore distribution of the total network and the reversible one. This allows a better distinction between the total network porosity and the closed porosity of the irreversible network. This technique was applied to standard cement-based mortars without and with 50% blast furnace slag. Thus, the microstructure evolution was followed after 28 and 360 days of maturation in wet cure by the proposed technique as well as by an exploration with SEM electron microscope. A careful analysis of the results showed the effectiveness of the tested approach in terms of understanding the matrix microstructure (pore size and accessibility). Moreover, the results have well demonstrated the expected positive effect of the slag on the densification of the mortar microstructure in the long term.Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 3rd International Congress on Materials & Structural Stability.