RU1782953C - Binder - Google Patents

Abstract

The inventive: cement contains, wt.%: Blast furnace granulated slag 15-30, Portland cement 15-30, lime 21-35, alkali metal sulfate 0.2-0.5, waste adipic acid production from the stage of oxidation of cyclohexanol or cyclohexanol logexanone 0.05-0.1 and dust-fly of ferroalloy production 18.75-34.4. An astringent is prepared by mixing together or separately ground components with the addition of alkali metal sulfate and waste product of adipic acid with mixing water. Characteristics of the curing agent: after heat treatment, the compressive strength is 70-74.4 MPa, bending 8.5-9.2 MPa, the corrosion rate after 25 cycles is 0.001-0.04 g / m2, 50 cycles are 0.002-0.08 g / m2. 4 tab. Yo

Description

The invention relates to the building materials industry and can be used in the manufacture of binders and materials based on them.

It is known to be thickening, including slag-Portland cement, 79.4-89%, lime 2.5-10.7%, siliceous component (syshtof) 8-8.7%, hardening accelerator (CaSU 0.5-1.2%).

Known in baking, including slag 30-45%. lime 10-30%. dust-fly of ferroalloy production 10-50% and gypsum 1-4.

The closest in technical essence, its composition and the achieved result is a binder, including blast furnace wet granulation slag, Portland cement, lime and alkali metal sulfate. The weight ratio of slag to Portland cement and lime is in the range of 0.5-100.

A disadvantage of the known binder is the insufficient corrosion resistance of steel reinforcement.

The aim of the invention is to increase the corrosion resistance of steel reinforcement.

This goal is achieved in that the thickener, including blast furnace granulated slag, Portland cement, lime and an alkali metal sulfate, additionally contains a waste of adipic acid production from the stage of oxidation of cyclohexanol or cyclohexanone and dust removal of Ferroalloy production - for the following ratio of components, wt.% :

Granulated blast furnace

SJ 00 Yu Yu SP y

15-30 15-30 21-35

0.2-0.5

0.05-0.1

slag

Portland cement

Lime

Alkaline sulfate

metal

Indicated waste

production

adaptin

acid

Ferroalloy dust

production18.75-34.4

Use the following materials.

Quicklime complying with the requirements of GOST 9179-77 Building lime. Technical conditions According to the content of CaO and CoO, lime activity is at least 70%.

Portland cement in accordance with GOST 310.1 - 3-76. Cement grade not lower than M400.

The hydraulic activity of blast furnace granulated slag should be determined in accordance with GOST 3476-74, the chemical composition should be determined in accordance with GOST 5382-73.

The chemical composition of blast furnace granulated slag should be within:

SI0237.50-37.88%

CaO39.5-45.22%

MDO6.66-8.17%

And aOz 7.8-14.16%

ReaOz 0.52-0.98%

Na20 + K200.21-0.85%

FeO0.8-3.24%

The waste of adipic acid production consists of 1) adipic acid, 2) glutaric acid, 3) succinic acid. The ratio between these acids should be A: G: I-2-2.5: 3-3.5: 1-1.5. The content of copper 2-valent nitrate is 2-3% and medovanoammonium is 1.5-2.0%.

The large-tonnage waste of the metallurgical industry, dust-fly-off of ferroalloy production of silica fume, is an ultrafine dust-like material captured by bag filters of the gas treatment system of furnaces in which ferrosilicon is smelted. The chemical composition of silica fume is presented in Table. 1.

The waste of the production of dibasic organic adipic acid (HOOC- / CH2 / 4-COOH) is formed at the stage of oxidation of cyclohexanol or cyclohexanone with nitric acid or atmospheric oxygen in the presence of manganese salts, the symbol is OD.

p LJ

.lnip yuo with

HiCkJcHj + 8HN ° J HOOC- (CH2) HCOOH 7H, 0 + 8MO

cn

,

cng g

COOH + HjO + INO

10

The components are used in their optimum ratio, which makes it possible to obtain concrete products of increased strength and increased corrosion resistance of steel reinforcement (the necessary alkalinity of the pore fluid).

Introducing silica into the system

component, which is silica fume, less than 18.75% and lime less than 21% reduces the number of neoplasms in the initial stages of hardening and does not provide a dense concrete structure.

An increase in these components to 34.4% and 35%, respectively, reduces the amount of Portland cement and slag in the system, which is accompanied by an insufficient set of strength in the long-term hardening periods,

The addition of alkali metal sulfate to the constituent (for example, No. 2804) and waste production of adipic acid increases the reactivity of the mixing medium, i.e. increases the pH of the medium, which provides hydration of the silicate and aluminate constituent slags, and also provides long-term passivation of steel.

It was experimentally established that the content of alkali metal sulfate is less than 0.2%, the waste of adipic acid production less than 0.05% does not lead to a significant increase in strength, and also does not provide the necessary alkalinity of pore

liquids. The introduction of an alkali metal sulfate of more than 0.5% and a waste of more than 0.1% becomes unnecessary, because already the amounts of introduced substances are affected by corrosion of the reinforcement, and

porosity and decreases the average density of concrete, which can lead to the appearance of corrosion of reinforcement in concrete during operation of products from it in aggressive environments, the concrete strength is also significantly reduced,

The hardening process is driven by hydration of clinker minerals with the formation of hydroaluminates of hydroaluminates, calcium hydroferrites, complex salts and calcium hydroxide

which acts on the vitreous phase of the slag component, disrupts the structure and leads to the formation of aluminates and calcium silicates, which are subsequently released from the solution.

Silica particles, which are part of the ferroalloy waste, interacts with calcium hydroxide Ca (OH) g to form hydrosilicates. The further course of this reaction is ensured by the appearance of new groups, SI-0-H, due to hydrolysis, which is promoted by an increased concentration of hydroxyl ions as a result of the dissolution of calcium hydroxide in water.

The alkaline component of the binder intensifies destruction in the hydrolytic dissolution of slag, provides the formation of alkaline hydroaluminosilicates and the creation of an environment that promotes the formation and high stability of low-basic calcium hydrosilicates.

Additives do not contain aggressive chlorine ions. The constituents of the waste from the production of adipic acid and waste from the ferroalloy production react with the components in the binder. This results in neoformations in the form of tiny finely dispersed particles, making concrete more dense with closed porosity and water-tight, respectively increasing the protective abilities of concrete, lowering the corrosion rate of steel reinforcement, and in the form sufficiently stable passive films over the entire surface of the reinforcement.

When calcium oxide interacts with water, a large amount of heat is released within 2-4 hours (277 kcal / kg CaO). This occurs to a significant thermal effect on the composition and the intensive growth of its strength in the initial period of hardening. For comparison, it should be noted that during the interaction of Portland cement with water, only 100-12) kcal / kg is released within 28 days.

The weight ratio between calcium oxide and active mineral supplement has a particular effect on the normal hardening of the system. If the latter is deficient in the mixture with respect to calcium oxide, fluxing of the hydroxide and violation of the integrity of the system with the formation of cracks occur.

An example embodiment of the invention. In order to obtain binder, the lime is crushed to a particle size of not more than 10 mm, then a joint noiv-ol of the components into the binder or mixing of pre-ground materials is possible.

The specific surface of the cement should be in the range of 4000-5000 cm2 / g. The fineness of cement grinding according to the residue on sieve N 008 does not exceed 5-7%. The binder is in accordance with the requirements of the standard in terms of uniformity of volume change (GOST 310.3-76). The physicomechanical characteristics of the binder are determined according to GOST 317.1-3-76. The density of the cement paste is normal within 50 minutes. - start of setting. 2 h 08 min - the end. An astringent makes it possible to obtain cements with activity determined according to GOST 310.4-81, corresponding to grades 600 and 700. To reduce the loss of activity of cement, it should be stored in three-layer bags in closed containers. Investigations were carried out on cement beam samples of composition 1: 3 (cement: sand) with a consistency characterized by 110 mm cone fusion and a water ratio of 0.49. In order to achieve better uniformity, intensive mixers can be used . The adipic acid waste additive and alkali metal sulfate are introduced with the mixing water. During molding, steel samples of a cold-wound class B-1 reinforcing wire with a diameter of 5 mm are inserted into the middle of 4x4x16 cm beam samples so that the thickness of the protective layer on all sides is at least 2 cm. To compare the inhibitory effect of additives and change in strength Characteristics were prepared samples from the compositions of the prototype. The cementitious compositions for concrete mixtures and the physicomechanical characteristics of the samples are presented in Table. 2 and 3.

It is recommended that the prepared samples of the beam after molding be held for 1-2 hours under normal conditions. Heat and moisture treatment can be carried out in a steaming chamber according to the regime. 2-3 hours - heating to 85 ° C. 6-8 hours - holding at 85 ° С and 3-4 hours cooling. The process of heat-moisture treatment can be carried out in a drying chamber at a holding temperature above 100C.

Beam samples are prepared with a size of 4x4x16 cm, composition 1: 3 (cement: sand). Compounds shown in Table 1 are used as cement. 2. Samples are prepared according to the technology described above. After molding, the samples are kept under normal conditions for 1 hour. Next, the molds are placed in a steaming chamber and the samples with molded reinforcing bars are subjected to heat and humidity treatment according to the regime: 2 + 6 + 3/2 h - heating up to 85 ° С 6 h - holding at 85 ° С, 3 h - cooling

As can be seen from the data given in table. 3, the samples made on the basis of the described cement surpass the strength of the samples made on the basis of the prototype up to 15%. The same superiority in strength is achieved when storing samples 5 under normal conditions in accordance with GOST 310.4-81. It is important that the reinforcement in the samples manufactured on the described compositions practically does not corrode (compositions No. 3, Table 3) as compared to the reinforcement in the samples 10 made according to the prototype. In composition No. 2, the corrosion rate of the reinforcement after 50 cycles of alternate wetting and drying is 0.041 g / m2; and the corrosion rate of the reinforcement in the samples prepared according to the prototype is 2.46 g / m2.

The results of the impact of these wastes are presented in Table 4.

Research results show. 20 that the addition of additives alone reduces the rate of corrosion. Only the joint introduction of additives can significantly reduce the corrosion of the reinforcement and increase the strength value of the samples.25

The economic effect of using the invention lies in the fact that it allows to increase the durability of building products and structures and their term

operation 2 times in aggressive environmental conditions, receive products with desired properties and higher strength characteristics.

Claims (1)

Formula of the invention Cementing agent, including blast furnace granulated slag, Portland cement, lime and an alkali metal sulfate, characterized in that, in order to increase the corrosion resistance of steel reinforcement, it additionally contains an adipic acid production waste from the stage of oxidation of cyclohexanol or cyclohexanone and dust removal of ferroalloy production in the following ratio, May. %: Granulated blast furnace slag 15-30 Portland cement 15-30 Lime 21-35, Alkali metal sulphate t 0.2-0.5 Indicated waste adipine production acid 0.05-0.1 Ferroalloy dust, 18, 75-34, Table 1 Table 2  Test cases / Physico-mechanical characteristics of samples Continuation of table 2 Table 3 Table a Continuation of the table. 4