The development of the physicochemical properties of the leaven as it matures.
Physicochemical characteristics of the leaven in the maturation period: 1 – compressive strength. 2 – release of binding heat, 3 – degree of hydration, 4 – pH degree, 5 – conductivity.
The figure shows schematically the development of the most important physicochemical properties of the slurry, which are classified as marked in the drawing.
The values for the ideologically presented curves depend on the type of cement, which, if necessary, will be given later. The graph shows the relationship between the various properties – e.g. some curves go down, and others rise, what has a close relationship.
Strength of hydrated cement mass (cement stone) is according to the formula f = fo (1 – p)³; where: p is the pore volume, a fo= 240 MPa. fo suggests the potential strength resulting from the physicochemical laws assuming full tightness of the product, except for the gel pores.
Deformability
Such properties of the grout, like the initial plasticity of the mixture, in turn, the porosity of the cement stone and the constant moisture content in them cause, that both leaven, and the cement stone are deformable. Can distinguish:
• skurcz wewnętrzny, which arises as a result of contraction of bonding cement with water,
• skurcz zewnętrzny lub pęcznienie wywoływane zmianą wilgotności (it only occurs with changes in the moisture content in the cement product),
• odkształcenia termiczne wywoływane zmianami temperatury.
• odkształcenia typu mechanicznego powstają pod wpływem obciążeń zewnętrznych (the compressive load shortens the element, and stretching – elongation).
• skurcz samoistny, when there is too little water in the bonding concrete.