Abstract: A process for producing cement to be used when preparing an injection grout for prestressed concrete sheathes, comprising grinding together, at a temperature lower than 90.degree. C., Portland clinker which is free from any corrosive ions for steel, gypsum, an anhydrous water reducing additive and an also anhydrous cement set retarding agent, as well as cement obtained by means of this process and injection grout for prestressed concrete sheathes such as produced with this cement.

Abstract: The invention has for its object a device for measuring the slope parameters of a material contained in a cylinder rotated around the axis thereof.This device, which senses radiations generated by radio-isotopes passing through the cylinder and the material contained therein, comprises means 1 generating the said radiations and means 8a, 8b picking up the latter fitted outside the cylinder in such a manner that, during the rotation thereof, the radiation generated by the radio-isotopes passing through the slope of material 5 in at least two separate locations is sensed in a specific point of the cylinder, as well as means for analyzing the signals received by the means sensing said radiation.This device is to be used together with a rotating furnace and particularly a cement kiln.