Comparison of various methods applied in porous materials microstructure analysis in regard to hardened cement paste

Abstract

Porous materials are strongly prevalent among those ones applied in civil engineering. It is crucial to become thoroughly acquainted with material microstructure in order to understand the formation and potential use of investigated substance as well as to develop precise prediction models. The most important parameters describing porous material texture are: specific surface area, shape and volume of pores as well as pore size distribution. There are several methods, which provide such results, however each of them has some limitations. The main purpose of this paper is to compare results obtained by means of various methods commonly applied to microstructure investigation i.e. mercury intrusion porosimetry (MIP), low temperature sorption of nitrogen and thermoporometry (TPM) performed with water. The measurements are conducted on gamma aluminum oxide, which is characterized by one dominant pore diameter and hardened cement paste prepared using portland cement (CEM I 42,5R) with water-cement ratio equal to 0.5. The results obtained by the aforementioned methods are described and compared in detail in the report. Each of presented approaches has some drawbacks. Hence, in order to receive consistent description of porous microstructure one has to apply at least two different experimental methods.