CS198054B1 - Binding or sealing agents solidifying in low temperatures medium - Google Patents

Description

The present invention provides sealants and binders with inorganic binder components. More specifically, the invention relates to sealants and binders that solidify even in environments with an average daily temperature of less than + 5 ° C or + 8 ° C, or at temperatures below 0 ° C, and which at least partly contain cement.

One of the difficulties currently encountered in the production of sealants and binders is the requirement for these compositions to solidify at temperatures below the applicable standards, in other words, to solidify even at temperatures around freezing, or at temperatures much more lower. These requirements are found in particular in autumn and winter periods and in periods with sudden temperature fluctuations below freezing temperatures, in the field of connecting cast iron water pipes, in connection and repair of concrete building panels, in the manufacture and modification of concrete buildings and in repairing art monuments.

For example, world cement cementation adversely affects the effects of low temperature, which stops both solidification and hardening of binders (TC Bowers et al. Theory of Volume Changes in Hardened Portland Cement Paste during freezing. Res. And Des. Lab. PCA / 1954) 49/1954/49). Since it only occurs at temperatures below 17-20 ° C, it is usually required that Portland cement treatment be stopped when the temperature drops below -6 ° C. To avoid the disturbing effect of low temperatures on the freezing of portland198 054

19B 054 cement, various cements 8 were prepared by shorter solidification times and relatively high initial hydration heats. Attempts have also been made to lower the freezing point by admixing 1 to 4 wt. % of calcium chloride or sodium carbonate, potassium carbonate or sodium sulfate, etc. For example, SA Uironov (Theory and Methods of Concreting in Winter, Prague 1953) recommended that calcium chloride be mixed with sodium chloride, and LH Tuthill (AC Standarts-Recommended p. ' act. for winter concreting, J. Amer. Concr. Inst. 27, 10/1956/1023) suggested that, in cold weather concreting, a mixture of 1 wt. % of calcium chloride was aerated. A disadvantage, however, is the fact that calcium chloride increases the volume of the forming gels and interferes with their hardening, and in addition the shrinkage values increase. Sometimes during melting, material expansion or corrosion of the reinforcement can occur (R. Bárta: Chemistry and Technology of Cement, NČSAV Praha / 1961/279 to 280).

The known binders are also disadvantageous at low temperatures, i.e. when using cement-based binders of at least 450, at an average daily temperature of +5 ° C, when working with cement-based binders lower than 450 at an average daily temperature of +8 ° C and in environments with temperatures below 0 ° C. In such cases, the temperature of the mixture to be processed must not fall below + 15 ° C under normal use of binders and sealants, and must not be lower than + 10 ° C during concreting of massive constructions. In addition, in view of the heat losses arising from the filling and mixing of the material, the temperature of the concrete mixture components during transport and laying into the structure shall be at least +5 ° C and at least +10 ° C when preparing the concrete mix for interlaced concrete.

When solidifying and curing of monolithic concrete and reinforced concrete structures at low temperatures, their surface temperature must not fall below +15 ° C for 72 hours and for solid structures it must not be lower than +10 ° C (ČSN 73 2400: Execution and inspection of concrete structures, VÚNM) Prague 1970).

However, these conditions cannot be met and adhered to for the known binders or cementitious compounds, especially when working at permanently low average atmospheric temperatures or in case of larger outdoor temperature drops.

It has therefore proven expedient and advantageous to provide binders which do not have the above-mentioned disadvantages, in particular which will solidify even at average temperatures which are substantially lower than those permitted by the applicable standards or regulations. There was also a need to address the use of suitable inorganic binder-based sealants based on the principle of silicates, especially cement, which are suitable for repairing, joining and treating concrete panels and building materials other than concrete.

This object is achieved by the present invention, the object of which is to use a mixture of 5 to 99.94 wt. % cement clinker having a specific surface area in the range of 150 to 3,000 m / kg containing 2 to 95 wt. % of particles up to 5 microns in size, further from 0.0025 to 10 wt. % of lignosulfonate based on the total amount of cement clinker, and from 0.05 to 60 wt. % of the mixed water, and optionally other additives necessary for the preparation of mortars and concretes, such as fillers, regulating agents, wetting agents and coloring agents, such as binders or sealants solidifying in the low temperature environment in the range of +8 to -40 ° C.

198 05

Until the date of filing of this application, silicates based cements or binders have not been used or described, which in the case of cements of at least 450 solidify at average temperatures substantially lower than +5 ° C and in the case of cements of lower than 450 solidify at average temperatures considerably lower. than +8 ° C, and generally solidify at temperatures below 0 ° C.

In the description of the invention, no. No. 198,053 discloses a chemical composition of a cement clinker binder consisting of 5 to 99.94 wt. % cement clinker having a specific surface in the range of 150 to 3,000 m / kg, containing 2 to 95 wt. % of particles up to 5 microns in size and Z 0.0025 to 10 wt. % of a lignosulfonate-based substance and from 0.05 to 60 wt. % of admixture water, optionally from other additives necessary for the preparation of mortars and concretes. The aim of the present invention was to prove that by selecting certain granules of cement clinker and precisely adjusting their predetermined ratio at temperatures such as ČSN 73 2400, i.e. at temperatures of +8 ° C and higher, an optimum cement strength improvement was achieved. It was neither known nor foreseeable that the binder of the above composition could be used at low temperatures.

The mixtures described in the description of the invention to U.S. Pat. No. 198,053 can advantageously be used as binders which also solidify in the temperature range of +8 to -40 ° C and can therefore be used in construction work carried out at temperatures around 0 ° C, or even far below zero.

The advantages of this solution are evident from the following examples which illustrate the invention without limiting it in any way.

Example 1

Preparation of cement paste

The cement slurry is treated at + 3 ° C from ground clinker from PrachoΛ O vice at -7 ° C and a specific surface area (according to Blaine) in the range of 730 nr / kg containing 30 wt. % of particles below 5 microns. After stirring in water at +2 ° C for 5 minutes, a slurry of water coefficient 0.23 containing 2 wt. % sodium lignosulfonate and 1 wt. % of potassium carbonate, calculated on the total weight of the cement. The slurry mold is then stored in an environment at a temperature ranging from -6 to -8 ° C. The slurry solidifies in about 30 to 40 minutes, after 12 hours the mold is removed and the body is stored at a temperature in the range of -6 to -8 ° C until strength tests are performed. After 24 hours of rest, the compressive strength was determined to be 3.7 MPa, after 7 days 30.0 MPa and after 28 days the strength was 45.0 MPa.

198 054 Example 2

Cement putty for water pipes

48 parts of finely ground cement clinker containing at least 0.1 wt. % of potassium lignosulfonate, calculated on the total amount of clinker, 16 parts lead white, 4 parts lead clinker and 2 parts rosin blended with about 50% old linseed oil, calculated on the total weight of the final product.

Example 3

Preparation of silicate binder

The binder is prepared at a temperature of +5 ° C in a ratio of 1: 3 from finely ground clinker from the Prachovice cement plant with a specific surface (according to Blaine) of 700 m / kg, which has 24 wt. % of particles smaller than 5 microns, from sand at -7 ° C and continuously decreasing granulation and from water at +2 ° C. 1.8 wt. % sodium lignosulfonate and 1.4 wt. % of potassium carbonate, calculated on the total amount of clinker. After stirring for 15 minutes, the formed nialta having a water coefficient of 0.31 is incorporated into the molds and stored at rest in a temperature range of -6 to -8 ° C. After 30 to 40 minutes of slurry. solidifies and hardens after 60 minutes. After about 4 hours, the formed bodies are removed from the molds and stored at a temperature in the range of -6 to -8 ° C. After 24 hours the strength of the bodies is 3.3 MPa, after 7 days it reaches 20.0 MPa and after 28 days it reaches 24.0 MPa.

Example 4

Preparation of silicate binder for sculpture repair

Ground Cement Clinker Boundary with a specific surface area of 2 900 m ² / kg, at a temperature of + 20 ° C, is mixed at a temperature of + 5 ° C in a ratio of 1: 3 with a continuously decreasing granulation sand and water at +3 ° C. 3 wt. % sodium lignosulfonate, 2 wt. % sodium carbonate and 1.1 wt. % orthoboric acid. After 20 minutes of mechanical agitation, the mixture has a water coefficient of 0.40, filled into molds where it is allowed to stand at ambient temperature between -6 and -8 ° C until the beginning of the strength tests. The products solidify in about 15 minutes and after 20 minutes harden. In the tests, a compressive strength of 9.0 MPa, 24 hours 18.0 MPa, 7 days 50.0 MPa and 28 days 60.0 MPa is achieved after 3 hours from the start of mortar mixing.

Example 5

Preparation of binders

The procedure of Example 3 is repeated, except that the temperature is +15 ° C and that the cement, sand and water are at + 20 ° C. After perfect mixing

198 05 of the mixture, the molded binder is placed in an environment having a temperature of -18 to -21 ° C and stored after 12 hours until mechanical testing is performed. In the case of finished products, after 24 hours, the compressive strength was determined to be 4.5 MPa, after 7 days the strength was 9.1 MPa and after 28 days the strength was 10.0 MPa.

Example 6

Preparation of putty for marble materials with average pour point not exceeding +5 ° C of finely ground gypsum-free cement clinker and 0.5 wt. % of calcium lignosulfonate, calculated on the total amount of cement clinker, is mixed with 12 wt. parts of slaked lime, 12 parts of fine sand and 2 parts of diatomaceous earth, the resulting mixture being treated with a thick slurry of aqueous sodium silicate.

Claims (1)

Use of a mixture consisting of 5 to 99.94 wt. % cement clinker having a specific surface in the range of 150 to 3,000 m / kg, containing 2 to 95 wt. % of particles up to 5 microns in size, from 0.0025 to 10 wt. % of lignosulfonate based on the total amount of cement clinker, and from 0.05 to 80 wt. % of the mixing water, optionally containing additives necessary for the preparation of mortars and concretes, such as fillers, control additives, wetting agents and coloring agents, such as binders or sealants solidifying in the low temperature environment in the range of +8 to 40 ° C.