SU767051A1 - Straining cement - Google Patents

Description

one

This invention relates to a composition of cement, for example, applied to the south for reinforced concrete structures with increased crack resistance, strength J and watertightness.

Known cement containing, wt.%: Portland cement 75, alumina cement 15, gypsum 10. The self-stress energy of this Q composition is controlled by decreasing or increasing the percentage of alumina donna and gypsum fl3

Stress cement is also known, including Portland cement, calcium sulfate, a substance containing calcium aluminates and lime 2.

The disadvantages of these cements are that with a higher content of the alumina component and gypsum "

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the free strength of the concrete is reduced and the concrete mixture is not capable of processing, since the beginning of the setting occurs in 1-5 minutes,

and the end of the setting is 5-10 min. 25 after being sealed with water.

The aim of the invention is to increase the energy of self-stressing of the tensioning cement.

The goal is achieved by the fact that the tension cement, including Portland cement, aluminous slag, gypsum and lime, additionally contains the sodium salt of the condensation product of naphthalene sulfonic acid and formaldehyde in the following ratio of components, wt.%:

Aluminous slag 3-25 Gypsum2-15

Lime1-7

The sodium salt of the product 0.1-1 condensation of naphthalene sulfonic acid and formaldehyde Portland cement Else

Concrete mixes are made on tension cements, each containing, wt%: alumina slag 15, gypsum 8, lime 4, and differing from each other in the content of the sodium salt of the naphthalene sulfonic acid condensation product and formaldehyde, equal in each mixture successively, wt.%: 0 ,one; 0.5; 1.0, -a well with Portland cement content, respectively 72.9; 72.5; 72. The sodium salt of the condensation product is introduced when making concrete blends together with mixing water. From the concrete mix is made of &

The results are shown in the table.

As can be seen from the table, the values of self-stress in strains of cement with the addition of the sodium salt of the product of condensation of naphthalene sulfonic acid and formaldehyde significantly exceed the same values of the known strain gauge.

The optimal addition of the product of condensation of naphthalene sulfonic acid and formaldehyde ngsysodits in the range of 0.1-0.5 wt.%, And with a further increase in its amount, the amount of air pressure of self-stress changes little, but the strength of eton increases.

The application of a stress, for example, when forming bulk blocks, makes it possible to significantly reduce the number of scrap by eliminating shrinkage and technological tressins, improve the quality of the front surfaces, save cement, and simplify the manufacturing technology.

Claims (2)

. For example ,, Formula invention gayuschy cement, Portland cement clinker vkloochakmtsii, glinozeMttcTb Shpak, gypsum and lime, on t l ich ayusch and with the fact that, in order pov19Sh1eni energy samonapr voltage, oi dbpolnite no naftaliisulfokisloty comprises a sodium salt of the condensation product of formaldehyde and at Saeduyouf sobtis about components, wt.%: Gly1 oz "4ydy Ashdk 3-25 Gypsum 2-15 Lime1-7 The sodium salt of the product 0.1-1 condensation of naphthalene sulfonic acid and formic acid dehyde Portland Resource Sources, {financials at home during the examination 1. USSR author's certificate  1 © 799b, cl. C 04 B 7/54, 1953. 6 2. USSR author's certificate  253641, class From 04 To 7/35, 1967 (prototype).