RU2489463C1 - Bitumen-polymer paste - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: bitumen-polymer paste contains bitumen, a polymer additive, ethyl silicate and mineral filler. The polymer additive used is atactic polypropylene, the filler used is flue ash from Krasnoyarsk TPP-2, and the ethyl silicate is ethyl silicate-32. Components are in the following ratio, wt %: bitumen - 86-40; atactic polypropylene - 2-10; ethyl silicate-32 - 2-10; flue ash from Krasnoyarsk TPP-2 - the balance.

EFFECT: high heat resistance, frost resistance and low water saturation of the paste.

6 tbl, 4 ex

Description

The invention relates to compositions of bitumen compositions used in construction for waterproofing and sealing structural elements and structures.

Known bitumen-polymer composition for gluing roll materials and waterproofing of building, concrete and metal structures, including asphalt deasphalting tar of West Siberian oil or tar of West Siberian oil (92.5-94.0 wt.%), Divinyl styrene thermoplastic elastomer with a characteristic viscosity of more than 1.0 dl / g (3.5-5.0 wt.%) and catalytic cracking waste (1.0-3.0 wt.%) (RF Patent No. 2276678 C1, priority date 01/11/2005, publication date 05/20/2006, authors Korobkova V.M. et al., RU).

A disadvantage of the known composition is low frost resistance, characterized by the fragility temperature according to Fraas.

Also known is bitumen-rubber mastic, used as roofing materials, to protect metal, concrete and other substrates, as well as for sealing joints in road construction, containing (wt.%): Oil bitumen 59.0-80.5; bromobutyl rubber or butadiene rubber, or butyl rubber, or low molecular weight polyethylene 6.0-15.0; rapeseed oil or a fraction of C- _20- C ₂₆ P-olefins, or a waste from the production of trimers or tetramers of propylene 8.0-15.0; sulfur 0.5-1.0; dolomite powder of pellets from mining and processing enterprises 5.0-10.0 (RF Patent No. 2285024 C1, priority date 08.08.2005, publication date 10.10.2006, authors Ganieva T.F. et al., RU).

The disadvantage of this mastic is its large water absorption.

Known bitumen-mineral mixture for use in the construction of road, roofing and waterproofing coatings, adopted as a prototype, including bitumen or coal tar, low molecular weight polyethylene, engine oil, toluene and ethyl silicate in the following ratio, (wt.%): Bitumen or coal tar - 10-24; low molecular weight polyethylene - 0.38-1.7; machine oil - 1.0-3.6; toluene - 2.12-6.8; ethyl silicate - 0.75-1.15; mineral filler - the rest (USSR Author's Certificate No. 808440, priority date 03/11/1979, publication date 02/28/1981, authors Lavreg L.Ya. et al., RU, prototype).

The disadvantage of the prototype is the high water saturation, low heat resistance and frost resistance of the bitumen-mineral composition.

The technical problem solved by the proposed compositions of bitumen-polymer mastics is to expand the raw material base by using the ashes generated by the combustion of solid fuels to obtain mastics with improved physical and mechanical properties based on new mixtures.

The technical result obtained by the implementation of bitumen-polymer mastics of the proposed compositions is to increase the heat resistance, frost resistance, as well as to reduce the water saturation of the mastics.

To achieve the technical result provided by the invention, a bitumen-polymer mastic containing bitumen, a polymer additive, ethyl silicate and a mineral filler, according to the invention, contains atactic polypropylene as a polymer additive, Krasnoyarsk TPP-2 fly ash, and 32 ethyl silicate as a filler in the following ratio components, (wt.%): bitumen - 86-40; atactic polypropylene - 2-10; ethyl silicate - 32 - 2-10; fly ash of Krasnoyarsk TPP-2 - the rest.

The properties of the starting materials influence the achievement of the technical result.

For the preparation of mastic, road bitumen of the Achinsk Oil Refinery of the BND 60/90 brand was used as a binder. Table 1 shows the properties of the specified bitumen in comparison with the requirements of GOST 22245-90 “Viscous bitumen. Technical conditions. "

Table 1 The name of indicators Bitumen Properties GOST requirements 1. The softening temperature according to "KiSh", ° C 48 not lower than 47 2. The depth of penetration of the needle, mm · 10 ^-1 at 25 ° C 64.3 61-90 at 0 ° С 29.3 not less than 20 3. Elongation, cm at 25 ° C more than 1 m not less than 50 at 0 ° С 7.5 not less than 3,5 4. Water absorption under vacuum,% 0.45 - 5. The temperature of fragility according to Fraas, ° C -twenty not higher - 15

As can be seen from table 1, bitumen for all indicators meets the requirements of GOST 22245-90.

To increase the heat resistance, frost resistance and reduce the water saturation of the mastic, according to the invention contains ethyl silicate-32 (ETS-32) according to TU 2435-397-05763441-2003. According to the specified specifications, ethyl silicate-32 is a transparent, low-viscosity liquid, which is a complex mixture of oligoethoxysiloxanes with varying degrees of condensation. Ethyl silicate-32 has high heat resistance and can be used at temperatures from -50 to + 60 ° C. Ethyl silicates are classified according to the SiO ₂ content of ethyl silicate-32, ethyl silicate-40 and ethyl silicate-50. Studies have shown that ethyl silicate-32 has a better compatibility with bitumen, which contains a lower amount of polymeric alkoxylans and with a lower molecular weight, i.e. it is more liquid in comparison with ethyl silicate-40 and ethyl silicate-50. Therefore, the technology for the preparation of bitumen ethyl silicate binders with ethyl silicate-32 will be simpler than with ethyl silicate-40 and ethyl silicate-50, that is, the temperature and mixing time of bitumen with ethyl silicate-32 will be less than with other ethyl silicate grades. When using ethyl silicate-32, more homogeneous and, therefore, denser mastic compositions are obtained, which leads to a more effective reduction in their water saturation compared to the use of ethyl silicates of other grades. Ethylsilicate-32 is an effective universal additive that improves deformation ability at low temperatures, water resistance and adhesion to the concrete surface of bituminous mastics. Ethylsilicate-32 in bitumen has a double role: it is also a plasticizing and structuring additive. In the preparation of compositions, ethyl silicate-32 in bitumen is in a liquid state, soluble in bitumen oils, increasing the content of the frost-resistant part of bitumen, that is, it acts as a plasticizing additive. Due to this, it is possible to reduce the temperature of preparation and installation of bitumen-polymer mastics. Then, its hydrolysis in bitumen occurs with the formation of polymer gel products that structure bitumen. Thus, an additional elastic network of gel polymer hydrolysis products is formed in bitumen, which will increase the heat resistance, water resistance and frost resistance of bitumen-polymer compositions.

The properties of ethyl silicate-32 are shown in table 2.

table 2 Properties of ethyl silicate-32 The name of indicators The properties 1. The content of SiO ₂ ,% 32 2. Density at 20 ° C, g / cm ₃ 1.05 3. The content of fractions with a boiling point,% to 110 ° C 0.8 110-160 ° C 1,0 160-180 ° C 51 4. Auto-ignition temperature, ° С 180 5. Freezing temperature, ° C, lower -60

However, it should be noted that ethylsilicate-32 hydrolysis products have insufficient frost resistance during operation in Siberian regions. Therefore, in addition to ethyl silicate-32, it is necessary to introduce polymers into bitumen compositions.

Atactic polypropylene (APP), which is a by-product of polypropylene production, is selected as a polymer additive, and therefore its cost is much lower than other polymers. APP has increased heat resistance, water resistance and deformation ability at low temperatures. In this regard, it will increase elasticity at low temperatures, heat resistance and reduce the absorption of mastics. Therefore, the introduction of APP will enhance the action of ethyl silicate-32 while increasing heat resistance, frost resistance and reducing water absorption of mastics.

Atactic polypropylene according to TU 2211-022-02069318-04 is a rubbery substance of amorphous structure. The properties of the APP are shown in table 3.

Table 3 Properties of atactic polypropylene The name of indicators The properties 1. Appearance Light gray amorphous 2. Volatile content,% 3 3. Mass fraction of ash,% 3 4. The content of isotactic fractions,% 40 5. Drop point, ° C 130

6. The depth of penetration of the needle at a temperature of 25 ° C and a load of 100 g, mm · 10 ^-1 60 7. Melting point, ° C 120 8. Viscosity at a temperature of 180 ° C, SPZ 10,000

The fly ash of the Krasnoyarsk TPP-2 was used as a mineral filler in mastics, which is characterized by low water demand and is a finely divided gray powder obtained from the combustion of crushed brown coals of the Irsha-Borodinsky opencast. Data on the technological properties of ash are shown in table 4.

Table 4 Technological properties of fly ash Bulk density, g / cm ³ True density, g / cm ³ Sieve residue 008,% Water demand,% Setting time, min. The end of setting, min. 1,1 2,34 9.8 22.34 twenty 54

Table 4 shows that fly ash is a highly dispersed material and can be used as a mineral powder in mastics.

Work on the preparation of mastic include the following operations:

- bitumen preparation;

- preparation of bitumen-polymer binder;

- preparation of mineral fillers;

- preparation of bitumen-polymer mastics by dosing the ingredients and mixing them.

The preparation of bitumen consists in its melting, dehydration by heating at a temperature of 100-110 ° C until the foam is stopped and heated to a working temperature of 150-160 ° C. Since ethyl silicate-32 binds the water remaining in the bitumen, the evaporation process can be reduced.

The preparation of a bitumen-polymer binder consists in mixing the bitumen heated to the working temperature with atactic polypropylene for 20-25 minutes. Then the resulting mixture is cooled to a temperature of 100-110 ° C and ethyl silicate-32 is poured with continuous stirring. Heating the mixture after the introduction of the entire amount of ethyl silicate is allowed no more than 15-20 minutes.

Ash preparation includes drying, sieving to remove foreign objects, lumps and grains larger than 3 mm and heating to a temperature of 120-130 ° C.

Preparation of bitumen-polymer mastic is carried out by sequential dosing of bitumen-polymer binder and ash and mixing them in a mixer at a temperature of 100-120 ° C for 15-20 minutes. Due to the fact that the temperature of preparation of known bitumen-polymer mastics is 150-160 ° C, the introduction of ethyl silicate-32 leads to a reduction in energy consumption, i.e. to reduce due to this cost of mastics. The compositions and properties of the prepared mastic samples are shown in tables 5 and 6.

Table 5 The compositions of bitumen-polymer mastics Name of components The content of the compositions, wt.% one 2 3 four Bitumen 86 74 fifty 40 Atactic Polypropylene 2 10 2 10 Ethyl silicate-32 2 6 8 10 Fly ash rest rest rest rest

Table 6 Properties of bitumen-polymer mastics Mastic Properties Composition No. 1 Composition No. 2 Composition No. 3 Composition No. 4 prototype Softening temperature according to the “Ring and Ball” method, ° С 54.5 53.0 65.0 64.0 40-51 Water saturation,% wt. 0.1 0.5 0.3 0.4 0.9-2.0 Fraasa fragility temperature, ° С -22.2 -29.0 -27.0 -36.7 -15--27

As can be seen from table 6, the softening temperature, which characterizes the heat resistance, and the brittleness temperature, which characterizes the frost resistance, have large values, and the water saturation is lower for the proposed compositions of bitumen-polymer mastics than for the known compositions (according to the prototype).

Claims (1)

Bitumen-polymer mastic containing bitumen, a polymer additive, ethyl silicate and a mineral filler, characterized in that it contains atactic polypropylene as a polymer additive, fly ash from Krasnoyarsk CHP-2 as a filler, and ethyl silicate-32 as ethyl silicate in the following ratio of components , wt.%:
bitumen 86-40 atactic polypropylene 2-10 ethyl silicate-32 2-10 fly ash of Krasnoyarsk CHP-2 rest