RU2436819C1 - Asphalt mineral mixture - Google Patents

Abstract

FIELD: construction. ^ SUBSTANCE: asphalt mineral mixture includes asphalt binder, mineral aggregate and mineral filler. Road oil asphalt is used as asphalt binder. Crushed sand of dense rocks with particle size of 0.16-5.00 mm is used as mineral aggregate. Mixture of phosphogypsum with particle size of less than 0.16 mm and limestone mineral powder is used as mineral filler. Ratio of components is as follows, wt %: asphalt binder - 6.5-7.0; crushed sand of dense rocks - 74.3; phosphogypsum - 3.7-3.9; limestone mineral powder - the rest. ^ EFFECT: obtained mixture has increased strength, and heat and crack resistance. ^ 2 tbl, 1 ex

Description

The invention relates to construction and can be used to obtain composite materials based on bitumen binders used in road, airfield, roofing.

The closest in technical essence to the present invention are hot asphalt mixes and sand-type asphalt concrete G, containing oil road bitumen, mineral aggregate - crushed sand from dense rocks and filler - limestone mineral powder (GOST 9128-97. Asphalt concrete, road, airfield mixtures and asphalt concrete. Technical conditions). The specifications of the above GOST normalize the minimum allowable values of the physical and mechanical properties of hot asphalt mixtures of sand type G, regulate the use of mineral powders for these mixtures.

The technical result of the invention is the creation of a bituminous-mineral composition of increased strength, heat and crack resistance using highly dispersed, multi-ton industrial waste of the chemical production of phosphate fertilizers - phosphogypsum (CaSO ₄ · 2H ₂ O).

The specified technical result is achieved in that the bitumen-mineral composition comprising a bituminous binder contains crushed sand from dense rocks of fractions from 0.16 to 5.00 mm and a filler in a rationally selected ratio of a mixture of phosphogypsum fractions less than 0, as a mineral aggregate 16 mm and limestone mineral powder in the following ratio of components, wt.%:

Bituminous binder - oil road bitumen - 6.5-7.0;

Crushed sand from dense rocks - 74.3;

Mineral filler:

Phosphogypsum - 3.7-3.9;

Limestone mineral powder - the rest.

Phosphogypsum taken from the dumps is dried to stabilize the weight and is further crushed in a ball mill, dispersed into fractions and screenings of fractions less than 0.16 mm are selected.

Example. Compositions of bitumen-mineral compositions were prepared (Table 1). The bitumen-mineral composition was prepared as follows: aggregate, filler and bitumen were heated to a temperature of 155 ± 5 ° C, mixed and compacted under a press at a pressure of 40 MPa for 3 minutes in cylindrical metal forms (the dimensions of the sample cylinders were 50 × 50 mm). The determination of physical and mechanical properties was carried out according to GOST 12801-98.

The test results of the bitumen-mineral composition are presented in table.2.

As can be seen from tables 1 and 2, the consumption of bitumen in the bitumen-mineral composition is accepted in the range of 6.5-7.0 wt.%. When bitumen consumption is less than 6.5 wt.%, For example 6.0 wt.% (Composition 1), strength indicators, heat resistance, water saturation W do not meet the requirements of GOST 9128-97 (table 2). When the bitumen content in the mixture is more than 7.0 wt.%, For example 7.5 wt.% (Composition 4), strength indicators and water resistance coefficient k _c are reduced.

The content of phosphogypsum in the filler is taken in the range of 3.7-3.9 wt.%. When the content of phosphogypsum in the filler is less than 3.9 wt.%, For example 2.8 wt.% (Composition 6), the strength R ₂₀ and heat resistance R _{50 are} reduced. When the content of phosphogypsum in the filler is more than 3.9 wt.%, For example 4.8 wt.% (Composition 7), strength indicators, heat resistance and water saturation deteriorate.

From a comparison of the quality of the proposed mixtures (compositions 2 and 3) with the prototype (composition 9, the requirements of GOST 9128-97 for hot dense asphalt mixes type I-III grades), the following advantages are obvious over it, namely (on average):

120.0% increase in compressive strength at 20 ° CR ₂₀ ;

76.0% increase in heat resistance R ₅₀ ;

39.0% lower values of compressive strength at 0 ° C (R ₀ ), which indicates increased crack resistance.

The introduction of phosphogypsum in rationally selected proportions into the filler (limestone mineral powder) can significantly improve the strength, heat resistance and crack resistance of the proposed bitumen-mineral compositions, which at the same time opens up a new opportunity for the disposal of this multi-tonnage industrial waste.

The combination of the above positive properties of the proposed technical solution allows to increase operational characteristics and expand the scope of phosphogypsum in the structural elements of coatings using the proposed compositions of bitumen-mineral compositions.

Table 1 BITUMINOUS AND MINERAL COMPOSITION Components Content, wt.% Prototype Suggested compositions one 2 3 four 5 6 7 8 9 Bitumen grade BND 60/90 6.0 6.5 7.0 7.5 7.0 7.0 7.0 7.0 6.0-9.0 Sand from dense rocks of fractions of 0.16-5.0 mm 74.3 74.3 74.3 74.3 74.3 74.3 74.3 74.3 66.0-79.0 Phosphogypsum fractions less than 0.16 mm 3.9 3.9 3.9 3.9 1.9 2,8 4.8 5.7 - Limestone Mineral Powder Rest Rest

table 2 BITUMINOUS AND MINERAL COMPOSITION Indicator Physico-mechanical properties of the compositions Test results of the proposed compositions Prototype one 2 3 four 5 6 7 8 9 Compressive strength at 0 ° C, R ₀ , MPa 6.4 6.9 8.4 7.3 8.5 8.0 7.1 7.0 No more than 9.0-13.0 Compressive strength at 20 ° C, R ₂₀ , MPa 3.2 4.3 5,6 4.1 4,5 4.2 3.9 3,7 No less than 2.0-2.5 Compressive strength at 50 ° C, R ₅₀ , MPa 1,6 2.1 2,3 1.9 2.0 1.9 1.8 1,5 Not less than 0.9-1.6 Water saturation, W,% 5.5 3,5 2.9 2.6 1.8 2,3 5,0 6.3 1.5 to 4.0 Water resistance coefficient, k _in 0.9 0.9 0.9 0.88 0.95 0.92 0.87 0.82 Not less than 0.7-0.95

Claims (1)

Bituminous-mineral composition, including binder - road petroleum bitumen, mineral aggregate - crushed sand from dense rocks of 0.16-5.00 mm fraction and mineral filler, characterized in that it contains a mixture of phosphogypsum fraction less than 0.16 as a mineral filler mm and limestone mineral powder in the following ratio of components, wt.%:
bitumen binder - oil road bitumen 6.5-7.0 crushed sand from dense rocks 74.3
mineral filler:
phosphogypsum 3.7-3.9 limestone mineral powder rest