Components of the internal structure of the hardened grout
When analyzing the internal structure of the ripe grout, it can be taken figuratively, that the cement stone is "micro-concrete” composed of:
• reliktów ziaren cementowych (meeting the aggregate roadstead),
• zhydratyzowanego cementu w postaci żelowokrystalicznej (the role of the binder),
• wody wolnej, because not all of the mixing water is chemically combined with the cement,
• pustek powietrznych kontrakcyjnych, gel and capillary with varying degrees of moisture.
Contractual pores are created as a result of a reduction in the volume of hydrated cement in relation to the sum of the volume of cement and water, that merged with each other. The volume difference is approx 25% the original water volume, which reacted. The diameter of these pores (row 0.1 nm) she is so small, that they do not affect the watertightness and can be included in the gel pores.
The capillary pores initially constitute a volume equal to that of the mixing water (you can say, that the capillary pores are then filled with water). As the hydration process takes place, they change their structure and the extent of moisture. In the final state, they are ball-shaped, lenses and threads with a diameter of up to 0,5 μm, and can be closed, blind or open, connecting into the spatial lattice and with the surface of the product (leaven, concrete). The higher degree of pore openness reduces the water resistance of the cement stone. Hollow capillary pores are formed by the evaporation of excess water from the leaven. As a rule, the surfaces of the gel pores are covered with water (gel water).
From the above, a very important conclusion can be drawn regarding the execution of concrete. The more batch water, the hardened leaven is more porous, and the concrete made of it will be less tight and of lower strength. On the other hand, too little water does not allow obtaining sufficient workability, which also leads to leakage.