cement paste porosity
cement paste porosity
(OP)
Hello
Cement combination paste (i.e binary and ternary combination) should give lower porosity compared to cement paste. But I found the cement paste produce the lower porosity. do anyone know the reason. hope somebody can solve my puzzle.
ta XX
Cement combination paste (i.e binary and ternary combination) should give lower porosity compared to cement paste. But I found the cement paste produce the lower porosity. do anyone know the reason. hope somebody can solve my puzzle.
ta XX





RE: cement paste porosity
Also, might some of the components be pre-reacted or aged past the point of proper application? Or some way spoiled?
RE: cement paste porosity
RE: cement paste porosity
If the materials are less absorptive, the matrix formed in the combined paste must be allowing the formation of some form of structured shrinkage with the bigger porositiy.
This points again to first a formation of the bigger matrix, the additions upon reactivity taking part, and gaining strength, and then shrinkage happening supported upon such bigger matrix.
If such is the case, ensuring such hardened matrix can't form beforehand would be the way to go.
If coming from over-reaction, the additions being too fine could be the cause, but the formation of structures before the proper time could point exactly the contrary way, too coarse grains promptly reacting at their surface and allowing the bridging.
In any case, for mixes of materials well known to the chemical experts, I would look at the granulometry of the materials (and purity of the water).
RE: cement paste porosity
RE: cement paste porosity
There are many complex combinations of cement to balance the chemistry and fineness for the best performance for what is produced. There is not a simple answer to your question.
Much depends on the use of the cement and requirements for the paste properties. If you do not have enough volume, you will have to work within the current Types and variations that different manufacturers offer. If this is the case, contact a major cement supplier and talk to the technical lab people. They know more about cement properties and use since the involvement of international ownership and high tech research.
For many years, we used a totally non-spec cement for the production of manufactured concrete elements. It was between a Type I and a Type III with a little extra air and a very short initial set. It produced a product that was superior in end use to the standard ASTM Type categories. The cement companies also liked to produce it because it was a relatively constant demand product and could be produced in the off-season and ground when the inventory got low.
RE: cement paste porosity