ABSTRACT
Two techniques that are simple and relatively fast to use are pycnometry and thermoporometry. Liquid and gas pycnometry provides information on total pore volume, but only limited or no information on other pore structure parameters, like pore size distribution and specific surface area. Therefore, the technique is not systematically used for characterization of cement-based materials. Thermoporometry was theoretically formulated almost 30 years ago, but is still under investigation and development for experimental applications. Thermoporometry, in combination with Nuclear Magnetic Resonance, is known as NMR cryoporometry and is discussed in Chapter 6. In this chapter, the principles and applications of pycnometry and thermoporometry are presented.
Pycnometry determines the density of a material by measuring the difference between the real (specific) and total (bulk) volumes of a specimen. Archimedes determined the volume of an object using the displacement principle by weighing the object, immersing it in water, and measuring the volume of water displaced. Modern pycnometry represents a refinement of the displacement principle and uses either a liquid or a gas substance as the displaced material.
