Some data on the timing of the sequence of cements C and F after aeration for 8 days in the laboratory were received. In both cements, the grasping timing has significantly lengthened. The same results were obtained in the factory by introducing small amounts of water (from 0, 25 to 0, 75%) to the mill when the cement is engaged. The tests of these samples for the degree of hydration showed that during the first 6 hours.
After the closing, they retained all the signs of fast-fast cements, t. e. did not find a noticeable increase in the degree of hydration. Obviously, the influence of aeration or preliminary hydration on the setting time can be explained by the fact that hydrate shells are formed around the cement grains that do not allow them to connect and acquire the initial strength. Slove the subsequent hydration after closing the cements with water confirms that they should be slowly hardening.
The Rebuf in one of his last articles indicated that since clay -earth cement is an expensive product intended for special purposes, it is necessary to seriously study the influence of his constitution on the properties. There is no doubt that there is still a lot to do in this area, which is more complex than the problem of Portland cement.
