High temperature resistant composite cement and preparation method thereof

Abstract

The invention provides high temperature resistant composite cement. The high temperature resistant composite cement is prepared from 48-72 parts of a portland cement clinker, 5-9 parts of gypsum, 11-17 parts of activated sludge, 12-33 parts of fly ash, 3-6 parts of limestone, 12-33 parts of electric furnace slag, 11-32 parts of granulated blast furnace slag, 2-4 parts of ceramic fibers and 2-5 parts of rubber powder. The high temperature resistant composite cement has the advantages of stable thermally recovered cement physical and chemical properties and easy engineering performance distribution. A preparation method of the high temperature resistant composite cement is simple, is convenient to operate and realizes a low cost, strong production controllability and good consistency of the product. The thermally recovered cement has high low temperature strength, prevents strength declining after high temperature treatment and has good high temperature resistance. Through use of phosphor slag and other slag, compressive strength reduction of aluminate cement in a hydration later period is solved and set cement compressive strength after treatment at a temperature more than 300 DEG C is guaranteed. Through use of ceramic fibers and rubber powder, the toughness of brittle aluminate cement is improved and downhole condition demands are satisfied.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a high temperature resistant composite cement and a preparation method thereof. Background technique [0002] Cement: powdered hydraulic inorganic cementitious material. After adding water and stirring, it becomes a slurry, which can be hardened in air or better hardened in water, and can firmly bond materials such as sand and stone together. The word cement is developed from the Latin caementum, which means crushed stone and flakes. The mixture of early lime and pozzolan is very similar to the modern lime pozzolan cement. The concrete made of it cemented with crushed stone not only has high strength after hardening, but also can resist the erosion of fresh water or salt water. For a long time, as an important cementitious material, it has been widely used in civil engineering, water conservancy, national defense and other projects. [0003] Composite Portland cement is a hyd...

AI Technical Summary

Problems solved by technology

However, due to the pozzolanic reaction between the calcium hydroxide produced by cement hydration and the mixed materials usually occurs in the middle and late stages of cement hydration, the early strength of composite cement is low

The adverse effect of a large amount of mixed industrial waste is also manifested in the lower flexural strength of cement, which increases the risk of shrinkage and early cracking of mortar and concrete

[0004] In the prior art, there is a technology for firing cement from domestic sewage treatment plant sludge. Adding less than 10% activated sludge to cement raw meal can increase the combustibility of raw meal and reduce the temperature of liquid phase formation. Although it is obvious Reduce the formation of f-CaO, but increase the content of C2S, reduce the content of C3S, change the cementitious mineral components in cement, and the incorporation of sludge affects the lattice structure of cement clinker, making cement Prolonged clotting time