Frost action in cement paste

Decalcification shrinkage of cement paste

Decalcification of cement paste in concrete is associated with several modes of chemical degradation including leaching, carbonation and sulfate attack. The primary aim of the current study was to investigate the effects of decalcification under saturated conditions on the dimensional stability of cement paste. Thin (0.8 mm) specimens of tricalcium silicate (C3S) paste, white portland cement (W...

Onset of cohesion in cement paste.

It is generally agreed that the cohesion of cement paste occurs through the formation of a network of nanoparticles of a calcium-silicate-hydrate ("C-S-H"). However, the mechanism by which these particles develop this cohesion has not been established. Here we propose a dielectric continuum model which includes all ionic interactions within a dispersion of C-S-H particles. It takes into account...

Drying Shrinkage Mechanisms in Portland Cement Paste

The shrinkage mechanisms of portland cement paste were investigated from shrinkage, weight loss, and pore structure measurements using nitrogen sorption and mercury intrusion porosimetry (MIP). Thin samples (2.3 mm) of well-hydrated (165 d) pastes of 0.4 and 0.6 water-to-cement (W/C) ratios were dried directly from saturated surface dry state to 75%, SO%, 11%, and 0% relative humidity (rh). Fro...

Rate Sensitive Behavior of Cement Paste and Mortar in Compression

Water dynamics in cement paste : insights from lattice Boltzmann modelling

Transport properties are often used as indicators of durability because water underpins most of the degradation mechanisms of concrete structures. The objective of this thesis is to understand the link between the microstructure and the permeability of cement paste, the binder phase of concrete. To achieve this goal, the lattice Boltzmann method is used to simulate the flow through three-dimens...