Micromechanical modelling of dry and saturated cement paste: Porosity assessment using ultrasonic waves

• Application of micromechanical models on cement based material.
• Mechanical and ultrasonic (velocities) properties were evaluated.
• Dry and water fully saturated cement paste were considered at various porosities.
• Experimental and modelled ultrasonic properties were compared.
• The Mori–Tanaka model succeeded in describing the acoustic parameters.

This article assesses the relationship between porosity and ultrasonic parameters of cement paste. It includes theoretical assessment of ultrasonic wave velocities of cement paste materials. Theoretical micromechanical models describing cement paste as a two-phase composite were detailed. Mechanical (bulk and shear moduli) and ultrasonic (longitudinal and transverse velocities) properties were evaluated. They were then, compared to the experimental ultrasonic properties measured on dry and fully water saturated samples with varying porosity First, the obtained micromechanical results showed that the correlation between acoustic velocity and porosity yielded the expected values: longitudinal and transverse velocities decrease with porosity. Secondly, the dilute inclusion model was able to represent the acoustic parameter of the cement paste only at low porosity, up to 20%. The self-consistent model under-estimated the measured ultrasonic properties for almost all porosity ranges. The Mori–Tanaka and the Kuster–Toksöz models succeeded in describing the acoustic parameters in dry and saturated states when assuming spherical shaped pores.