SU578276A1 - Cement - Google Patents

Description

one

The invention relates to construction materials and can be used in the production of fast-hardening Portland cement.

Known cement, including Portland cement clinker, two-water gypsum and polymer additive. As a polymer additive, a copolymer resin of products of pyrolysis of petroleum feedstock 1 is used.

The closest to the invention to the technical essence and the achieved result is cement, including Portland cement clinker, alunite rock annealed at 600 ° C and gypsum 2.

However, known cements are not hydraulically active.

The purpose of the invention is to increase the hydraulic activity of the cement.

This is achieved by the fact that cement, including Portlaid clinker, calcium sulfate and calcined alunite material, additionally contains a gel-forming organic additive in the following ratio of components, weight. %: Portland cement clinker80-90

Calcium sulfate 4,5-8

Annealed Alunite Material 5-15 Gel-forming Organic Additive 0.25-1.5

As a gel-forming organic

Cement additives contain at least one material from the group: acrylic acid, polyvinylbenzene, polyvinylpridine, water-soluble namine amines, sulfonated

polystyrene, sulfonic acids, their derivatives.

The essence of the invention is that when mixing the proposed cement with water, on the surface of the clinker grains occurs

a colloidal layer of hydrating gel-forming additive consisting of gel complexes with CaA cations of a colloidal additive solution in the liquid phase of the system. Due to the initial decrease in the content of these cations in the liquid phase, ettringite, formed from alunite, as well as calcium sulfate, is formed in the form of crystals of a more regular geometric shape, forming clear crystalline intergrowths.

The decrease in Ca concentration due to accelerated hydration of Alita 30–60 min after mixing is replaced by an increase, which leads to a coagulation of the colloidal solution.

additives and thickening of the complex layer of polymer gel. In this layer, A1 ions accumulate, which slowly diffuse to ettringite crystals growing under the protection of the gel.

Thus, as part of the proposed

Cement calcined alunite serves as a crystallization seed, releasing aluminum sulphate as reaction centers for the formation of ettringite.

Potassium sulphate, also released by calcined alunite, provides an increase in the permeability of protective gels of aluminum hydroxide and a polymeric additive to increase the rate of the chemical reaction for the formation of ettringite. The gel of the complex additive, the accumulation of Ca and A1 ions, accelerates the hydration of Alita clinker and provides a uniform supply of growing ettrnngite crystals with AF (SO4) ions ro.g game ;; protective colloid.

Improved crystallization of ettringite and an increase in the water permeability of the hydrated shells of cement grains increases the degree of hydration of cement and leads to an increase in its hydraulic activity.

The firing of alunite or alunitized rock to obtain a cement component is carried out using known methods at a temperature of 600-700 ° C to obtain A2SO4 K2SO4 and Y-AlaOs in the calcination product.

Calcium sulphate is preferred as a two-water modification.

Acrylic acid and its derivatives can be used as a gel-forming organic polymer additive, such as polyacrylamide, alkyl acrylates, alkylate; filates having from 1 to 7 carbon atoms in the alkyl group; polyvinylates: polyvinylbenzene, polyvinylpyridine and their hetero-cyclic derivatives; water soluble

polyamines: ethylenediamine, tetraacetic

acid (TDTA) and its analogs, polyarylamines and their heterocyclic derivatives, poloxiamines, polyaminophenols, polyamino sulfonic acids; sulfonated polystyrene and its mixture with acrylonitrile, as well as their chlorination products; sulfonic acids, their aromatic and heterocyclic derivatives.

Perhaps the use and mixtures of these materials.

Comparative data relating to the proposed and well-known cements with the use of YULS1 as a gel-forming additive for the aluminum salt of beisolsulfonic acid are presented in the table.

As can be seen from the test results, the proposed cement in comparison with the known has a high hydraulic activity,

Claims (2)

1. Cement, including Portland cement clinker, calcium sulphate and coated alunite material, characterized in that, in order to increase the hydraulic activity, the cement additionally contains a gel-forming organic additive at the following ratio of components, wt. %: Portland cement clinker80-90 Calcium sulfate 4,5-8 Annealed Alunite Material 5-15 Organic gel-forming additive0.25-1.5 2. Cement according to claim 1, characterized in that it contains at least one material from the group: acrylic acid, polyvinyl 3} polyol, polyvinylpyridine, water-soluble polyamines, sulfonated polystyrene, sulfonic acids, and their derivatives. Sources of information taken into account in the examination 1. The USSR author's certificate K 499239, cl. C 04B 7/54, 03/20/74. 2. USSR author's certificate jY 371185, cl. From 04B 7/02, 04.02.70.