CS199348B1 - Method of producing high-speed hardening hydraulic mixture - Google Patents

Description

The present invention relates to a process for the production of a quick setting hydraulic mixture.

V fis. copyright certificate no. No. 199347 discloses a rapid-hardening hydraulic composition comprising a mixture of 100 parts by weight aluminous cement, 2 to 40 parts by weight ground lime and / or lime hydrate, and 0.1 to 5 parts by weight anionic aulfonated aromatic or heterocyclic compound or a salt thereof. This mixture may contain 1 to 300 parts by weight of inorganic filler based on 100 parts by weight of aluminous cement.

Said composition has substantially better resulting physicochemical properties when produced by the process of the invention by first grinding aluminous cement, ground lime and / or lime hydrate and an anidive sulfonated aromatic or heterocyclic compound together so that the mixture has at least 85% particles of less than 45 µm, whereupon it co-homogenises with at least a portion of the inorganic filler.

The anni-active compound acts as a surfactant grinding material during the co-grinding of aluminous cement with lime and / or lime hydrate, which reduces the grinding time and saves the grinding energy while simultaneously mixing all the components of the mixture. By grinding the mixture to a fineness such that it contains at least 85% of particles smaller than 45 µm, a higher specific surface area is achieved and the risk of bulk instability due to the inhomogeneous composition of the mixture containing coarse or unmixed free lime particles is eliminated. Thereafter, it is homogenized with at least a portion of the inorganic >

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198 348 fillers. It is expedient to use silica sand as the inorganic filler. Thus, 1 sand can be used, e.g. it contains only coarser particles, and the milling required to achieve the required proportion of finer particles. A dry prefabricated mixture is prepared according to the process according to the invention, and it is sufficient to mix it with the necessary amount of mixing water immediately before use.

By interacting with aluminous cement, lime or calcium hydrate, an anionic organic substance, their fineness and the homogenization of the filler by grinding, new improved properties of the mixture are achieved over a mixture not treated by co-grinding. The following examples show the achieved properties:

The following materials were used for the tests:

(a) aluminate cement containing 79% by weight of particles of less than 45

% ai ₂ o ₃ % ^Pe 2 ° 3 % CaO % sieve ₂ % MgO particles less of them from 0.5 up to 2 mm

d) sodium salt of the sulfonated triamine-s-triazine condensate with formaldehyde was used as the anionic compound.

The quick-curing waterproofing composition of the present invention was prepared such that 100 parts by weight of aluminous cement, 25 parts ground lime, and 1.25 parts sodium sulfonated triamine-s-triazine-formaldehyde condensate were co-ground in a ball mill until such fineness was achieved that 96% of the particles were less than 45 µm. 100 parts of quartz sand, 0.5 to 2 mm in size, were then added to the mill, and after sufficient homogenization and grinding of the sand, the mixture was discharged from the mill and ready for use. The test mass reached a compressive strength of 4.5 MPa measured on 2x2x2 cm cubes after 15 minutes of adding 30 parts of water per 100 parts of mass. A mixture of the same composition, but prepared only by homogenizing the individual components without additional co-milling, after 15 min. from the addition of the mixing water, the compressive strength is only 2.8 MPa.

The tests used:

a / Aluminate cement with a proportion of 78% of particles less than 45 µm, containing:

39.22 % _Α ! ₂ ° 16.98 % Fe ₂ ° 38.10 % CaO 3.46 « SiO ₂ 0.27 % MgO

b) ground calcium hydrate with a proportion of 84% of particles smaller than 45 µm, containing 67 S CaO c / quartz sand containing particles from 0.5 to 2 mm d) as an anionic compound, sodium arylsulfonic acid-formaldehyde condensate was used as dry aldehyde powder.

199 348

The mass was produced as follows:

A ball mill was first mixed with 20 parts by weight of calcium hydrate and 1.25 parts of sodium arylsulfonic acid condensate, then 100 parts by weight of aluminous cement was added, then ground until it contained 85% of particles smaller than 45 µm, and 30 parts of quartz sand, and after sufficient homogenization and partial grinding of sand discharged from the mill and ready for use.

After adding 27 parts of water to 100 parts of the mixture, a mixture was produced which reached after 15 min. from the addition of water, a compressive strength of 5.0 MPa, measured on 2x2x2 cm test pieces. The watertightness test was performed as follows;

Substrate specimens of 20 x 20 x 12 cm were used, which already leaked at 0.2 MPa in the watertightness test. For this, a layer of a mixture of 100 parts of the mass according to the example and 27 parts of water in a thickness of about 4 mm was applied thereto. After 24 hours of curing, the samples were subjected to a water-tightness test and were subjected to water pressure so that every 24 hours the water pressure was increased by 0.2 MPa. The samples did not overflow even at a pressure of 1.0 MPa.

However, it is possible to add another portion of the inorganic filler - quartz sand - dodofine to the above mixture, after grinding is completed. Such a process is advantageous, for example, when the mixture needs to contain a coarser grain filler. In any case, it is necessary that at least a portion of the filler be ground together with a mixture of cement, lime and / or lime hydrate and an anionic compound.

The process according to the invention is suitable, in particular, where the mechanical strength and the waterproofing effect of the hardened mass are to be achieved particularly quickly after the addition of the mixing water to the dry, prefabricated mixture.

Claims (1)

A process for producing a quick setting hydraulic composition comprising 100 parts by weight of aluminous cement, 2 to 40 parts by weight of ground lime and / or lime hydrate 0.1 to 5 parts by weight of an anionic sulfonated aromatic or heterocyclic compound, or soluble salt thereof, and 1 to 300 parts of inorganic fillers, characterized in that the aluminous cement, lime and / or lime hydrate and the anionic sulphonated aromatic or heterocyclic compound are milled together so that their mixture has at least 85% particles smaller than 45 µm, while homogenizing with at least frequent inorganic filler.