GCP demonstrates Tytro RC performance against control and silica fume specimens by measuring void levels, or porosity, in the microstructure of three portland cement paste
Similar to the concept of PVC in paint, the larger the aggregate size, and the more rounded the aggregate, the lower the amount of cement and water required since more cement paste
is required to coat the surface area of smaller or more angular aggregate.
The factors that influence the modulus of elasticity of concrete depend on the characteristics of cement paste
matrix, transition zone, aggregate, and test parameter.
The most advanced concrete recycling technologies currently produce coarse ( 4mm) recycled concrete aggregates by removing cement paste
from the surface of the aggregates.
It can incorporate relatively large amounts of Na+ and K+ which displace Ca2+ in the lattice, and this can affect the pore solution chemistry of cement paste
which contains metakaolin.
This variable shows the influence of the vegetal species on the alkaline environment of the cement paste
and on the setting time of the mixtures.
The process starts from the contact surface of aggregate and cement paste
(Hagelia et al.
This must be due to the higher fineness of metakaolin (Table 2) resulting in better packing of the cements (within the paste matrixand at the interface zones between the cement paste
and the aggregates)and more nucleation sites for Ca[(OH).
Tomosawa  measured the isothermal heat evolution rate of Portland cement paste
A portion of the cement paste
of a conventional concrete (10-30 vol%) is replaced with an equal volume of foamed styrene/polystyrene resin.
The addition of fly ash increase the nucleation sites for the precipitation of hydration products in cement paste
and caused segmentation of larger pores which in turns resulted in a lower degree of pore continuity.
If the pressure of vapour is higher than the flexure strength of cement paste
, the cement paste
breaks and microcracks or explosive spalling are formed (van der Heijden at al.