RU2626083C1 - Raw material mixture for sulfur concrete and method of its preparing - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of preparing the mixture for sulfuric concrete involves mixing modified sulfur with a mineral filler heated to 150-155°C; the mineral filler includes pit sand with the grain size up to 5 mm and quarry crushed stone with the grain size from 5 to 40 mm; the hot mixture is discharged into moulds, cooled; at the temperature of about 40°C, the samples are removed from the mould, cooled to room temperature, at the following ratio of the stirred modified sulfur, pit sand and quarry crushed stone, weight parts: 1:(2.3÷4.2):(2.5÷4.5), respectively. The raw material mixture for the sulfur concrete includes crushed stone and sand. For preparation of the said mixture, crushed stone with the grain size of 5 to 40 mm, pit sand with grain size up to 5 mm, and modified sulfur are used at the following ratio, weight parts: pit sand 2.3-4.2, quarry crushed stone 2.5-4.5, modified sulfur 1, the raw material mixture for the sulfur concrete being obtained by the above method.

EFFECT: increasing the composition strength, corrosion resistance to aggressive media and to dynamic loads, reducing the water absorption, increasing the frost resistance.

2 cl, 2 tbl

Description

The group of inventions relates to building materials based on modified sulfur and can be used for the preparation of concrete and mortar mixtures in the construction and repair of various types of coatings: concrete, asphalt concrete, waterproofing.

A known method of producing a mixture for sulfur concrete (RF patent for the invention No. 2401819 C1, CL 04B 28/36, publ. 20.10.2010), which also describes the composition of the mixture for sulfur concrete. A method of obtaining a mixture for sulfur concrete involves modifying sulfur by introducing bitumen in it in an amount of 1-8 wt. % at a temperature of 125-155 ° C and exposure for 1-10 minutes with low frequency ultrasound. Modified sulfur is mixed with a mixture of mineral filler heated to 125-155 ° C - sand, gravel and fly ash with molten sulfur in a weight ratio of fly ash to sulfur (0.2-3.0): 1, at a weight ratio of modified sulfur to the specified mixture (0.001-0.05): 1. To obtain a mixture for sulfur concrete for paving, an additional 5-20 wt.% Is additionally introduced into said heated mixture of mineral filler and molten sulfur. % bitumen. The known method differs in the complexity and complexity of the process of obtaining a mixture for sulfur concrete, as well as low compressive strength of sulfur concrete obtained from the mixture.

A known method of obtaining FiSSH (fiber-slurry-gray-concrete) (application EA No. 2015500831 A2, CL 04/28, published on 12.30.2015). In the known method, in the first step, a sulfur binder is obtained — a modified sulfur (sulfur copolymer) produced from lump sulfur by means of a vortex layer apparatus. Then, at the second stage, FiBSS is obtained - in a mobile asphalt plant, sulfur binder and organic additives with inert fillers are mixed and heated to a temperature of no higher than 120 ° C for 20-30 minutes: drill cuttings, basalt fiber and building sand, as a result of which melting occurs modified sulfur (sulfur copolymer) in an environment of organic additives and inert fillers for dispersed reinforcement and composite. The known method allows to obtain a composition of sulfur concrete, which is resistant to external mechanical and temperature influences, aggressive environments, while it has increased crack resistance, hydrophobicity. The disadvantage of this method is that this method of producing sulfur concrete cannot be classified as safe, in addition, the method differs in the duration of preparation of the composition.

The closest decisions taken by the applicant as prototypes are a method for preparing a mixture for sulfur concrete (see RF patent No. 2382009 C2, CL 04/28, publ. 10/20/2010) and a raw material mixture for producing sulfur concrete (RF patent No. 2238010 C2, class C04B 28/36, publ. 10/20/2010). According to the method for preparing the mixture for sulfur concrete, a mixture of aggregates — crushed stone fractions up to 10 mm and sand with a grain size of up to 3 mm, preheated to a temperature of 160 ° C, is placed in a heated forced-action mixer, mixed, a binder — a mixture of sulfur, filler, heated to 160 ° C is added and a modifier - iodine, mixed, the resulting mixture is unloaded in a mold or paver, basalt screenings containing crushed stone, sand are used as the indicated mixture of aggregates. Their mixing is carried out for 1-2 minutes. The specified binder is used as a filler - the ash of the CHPP, sulfur and iodine. The specified binders and aggregate mixture are mixed for 2-3 minutes. The preparation of a known composition in accordance with a known method does not belong to the category of safe production, in addition, the method is difficult to prepare. Known raw mix contains, by weight. %: sand 24.07-33.64 and basalt screenings - crushed stone 31.65-44.26, ashes of thermal power plants captured 8.545-17.14, industrial sulfur 13.550-27.13, iodine 0.005-0.01. The known mixture does not have a high strength indicator.

The problem solved by the proposed group of inventions is to simply prepare the composition of the raw material mixture, resistant to aggressive environments and resistant to dynamic loads, which should meet safety requirements and should not include toxic components.

The technical result, the achievement of which the proposed group of inventions is directed, consists in the simplicity of preparation of the composition, increasing its tensile strength and frost resistance.

The technical result of the method of preparing the mixture for sulfur concrete is achieved due to the fact that the preparation of the mixture involves mixing modified sulfur with a mineral filler heated to 150-155 ° C, the composition of the mineral filler includes quarry sand with a grain size of up to 5 mm and quarry crushed stone with a grain size grains from 5 to 40 mm, the hot mixture is unloaded into molds, cooled, at a temperature of about 40 ° C the samples are removed from the mold and cooled to room temperature, the following ratio of mixed sulfur is modified Second, sand and gravel quarry career weight. hours: 1: (2.3 ÷ 4.2) :( 2.5 ÷ 4.5), respectively.

The raw mix for sulfur concrete includes crushed stone and sand, moreover, quarry crushed stone with a grain size of 5 to 40 mm, quarry sand with a grain size of up to 5 mm are used to prepare the mixture, the mixture also contains modified sulfur, weight. hours:

quarry sand 2.3-4.2; quarry crushed stone 2.5-4.5; modified sulfur one,

moreover, the raw mix for sulfur concrete is obtained as described above.

In the proposed raw material mixture, modified sulfur is used as a binder, which ensures the composition's resistance to aggressive environments. Moreover, the composition has increased frost resistance, as well as tensile strength to bending loads.

Sand and gravel are fillers and provide strength characteristics of the composition.

Table 1 shows the results of experimental studies of the proposed raw mix for the preparation of sulfur concrete. Strength tests were carried out with a compression speed of 1000 n / s using a press in which the manufactured test specimens were placed. Tests were carried out until the complete destruction of the samples. Table 2 shows the results of comparing the tensile strength (MPa) for the proposed composition of the mixture for sulfur concrete, including sulfur - 1 weight part; crushed stone - 4.5 parts by weight; sand - 4.2 weight parts, in comparison with the known (patent RU 2238010 C2) and Portland concrete grade B35.

For the preparation of the raw mix for sulfur concrete, quarry sand was used, for example, sand from crushing screenings, grain size of which is up to 5 mm, and quarry crushed stone, for example, granite or from gabbro-diabase, grain size from 5 to 40 mm. Physico-chemical parameters of modified sulfur must meet the requirements of GOST R 56249-2014, Technical sulfur. Technical conditions At the same time, various modifiers based on diene hydrocarbons (dicyclopentadiene), olefinic hydrocarbons, and oil refining wastes can be used to modify sulfur.

To prepare the samples, 100 kg of sand and 200 kg of crushed stone heated to 155 ° C were loaded into the mixer. Then, modified sulfur having room temperature in the amount of 60 kg was added to the obtained mineral filler with constant stirring and temperature control. Then, test specimens with a size of 100 × 100 × 100 (mm) were formed from a hot mixture (at about 145 ° C). Cooled to 40 ° C, the samples were removed from the mold and after 24 hours they were examined for strength.

In table 1, the following notation is accepted: S - modified sulfur, P - sand, Щ - crushed stone. The results of experimental studies, shown in table 2, make sure that the tensile strength index of the mixture prepared according to the proposed method has high values that are higher than 80 MPa. Table 2 shows comparative indicators of ultimate compressive, bending, and tensile strengths, as well as frost resistance parameters for the proposed composition in comparison with known mixtures. The frost resistance indicator characterizes the number of freeze-thaw cycles that concrete can withstand without losing its strength characteristics. The frost resistance parameter is the most important for concrete structures exposed to intense moisture (foundations, hydraulic structures). From table 2 it can be seen that the index of frost resistance of the proposed composition of the mixture significantly exceeds the indicators of frost resistance of analogues.

Thus, the resulting mixture composition for sulfur concrete has a high tensile strength, is resistant to aggressive environments and dynamic loads, while the composition meets the safety requirements and does not include toxic components.

Claims (4)

1. A method of preparing a mixture for sulfur concrete, including mixing modified sulfur with a mineral filler heated to 150-155 ° C, the composition of the mineral filler includes quarry sand with a grain size of up to 5 mm and quarry crushed stone with a grain size of 5 to 40 mm, the hot mixture is unloaded into molds, cooled, at a temperature of about 40 ° C, the samples are removed from the mold, cooled to room temperature, in the following ratio of mixed sulfur modified, quarry sand and quarry crushed stone, parts by weight: 1: (2.3 ÷ 4 , 2) :( 2.5 ÷ 4.5) respectively enno. 2. Raw mix for sulfur concrete, including crushed stone and sand, characterized in that quarry crushed stone with a grain size of 5 to 40 mm, quarry sand with a grain size of up to 5 mm are used for the preparation of the mixture, additionally the mixture contains modified sulfur, weight.h .: quarry sand 2,3-4,2 quarry crushed stone 2.5-4.5 modified sulfur one, moreover, the raw mix for sulfur concrete is obtained by the method according to p. 1.