KR101360986B1 - Low Thermal Conductive Asphalt Concrete Using Waste Vinyl Aggregate - Google Patents

Abstract

The present invention provides an insulating asphalt concrete prepared by mixing 1 to 10 parts by weight of the asphalt binder with respect to 100 parts by weight of the mixed aggregate of the general aggregate and waste vinyl aggregate of 80:20 to 99: 1.
The thermal insulation asphalt concrete of the present invention has a Marshall stability of more than 2000kg, not only has excellent strength than asphalt concrete using only crushed aggregates, but also has excellent water resistance as measured by tensile strength after freeze-thawing. In addition, the asphalt concrete of the present invention has a thermal conductivity of 1.2 Kcal / m · h · ° C or less, and has a great heat insulating effect. Therefore, when paving the road using the asphalt concrete of the present invention, it is easy to melt the snow or ice accumulated on the pavement in winter, and as a result it is advantageous to prevent traffic accidents.

Description

Low Thermal Conductive Asphalt Concrete Using Waste Vinyl Aggregate}

The present invention relates to thermally insulating asphalt concrete using waste vinyl aggregate, and more specifically, by mixing the aggregate and asphalt binder mixed with the general aggregate and waste vinyl aggregate, the high strength and low thermal conductivity on the pavement in winter The present invention relates to thermally insulating asphalt concrete using waste vinyl aggregate, which easily dissolves accumulated snow or ice and consequently prevents traffic accidents.

Various methods for recycling agricultural waste vinyl have been tried.

For example, Korean Patent Laid-Open Publication No. 2003-0018812, 2003-0038884 No. 2011-0095546, Patent No. 1119068, and the like disclose a method of fueling the collected waste vinyl, and Korean Patent Publication No. 2004 -0064319 discloses a method for producing a porous ceramic using waste vinyl.

One other way to recycle waste vinyl is to recycle it to civil engineering materials. For example, Korean Unexamined Patent Publication Nos. 2007-0067458, 2003-0029246, 2003-0067742, 2005-0076461, 2000-0043700, 2000-0043700, Patent 719136, 413902, 493864, and the like. Has disclosed technologies for utilizing the collected waste vinyl as a building or construction material. However, the use of recycling disclosed in the prior arts remains in general products that do not require high quality properties, such as sewer pipes, earth plates, highway boundaries, median, sidewalk blocks or snow plows.

Accordingly, the present inventors have made intensive efforts to expand and upgrade their use in recycling waste vinyl. As a result, most of the waste vinyl collected in rural areas is polyethylene-based polyethylene, such as HDPE, LDPE, LLDPE, and these materials have excellent thermal insulation properties. Focusing on the point, when recycling the waste vinyl into the aggregate for road paving, by utilizing the thermal insulation to lower the temperature of the asphalt pavement surface in summer, in winter it is confirmed that the snow accumulated on the pavement surface can be quickly melted and the present invention Completed.

An object of the present invention is to provide an asphalt concrete having a higher strength and lower thermal conductivity than conventional asphalt concrete while promoting recycling of petroleum resources.

Insulating asphalt concrete of the present invention for achieving the above object is prepared by mixing 1 to 10 parts by weight of the asphalt binder with respect to 100 parts by weight of the mixed aggregate of the general aggregate and waste vinyl aggregate of 80:20 to 99: 1.

The waste vinyl aggregate is preferably 5 to 50mm in size.

The waste vinyl aggregate may be to include pores formed therein.

The amount of soil components contained in the waste vinyl aggregate is preferably 20% by weight or less of the total weight of waste vinyl aggregate in weight ratio.

The thermal insulation asphalt concrete of the present invention has a Marshall stability of 2000kg or more, which is more than twice the strength of the asphalt concrete using only crushed aggregates, and also the water resistance evaluated by tensile strength after freeze-thawing is significantly higher than the asphalt concrete using only crushed aggregates. great.

In addition, the heat insulating asphalt concrete of the present invention has a thermal conductivity of 1.2 Kcal / m · h · ° C or less, which has a large heat insulating effect. Therefore, in the case of road paving using the insulating asphalt concrete of the present invention, it is easy to melt snow or ice accumulated on the pavement in winter, and as a result, it is advantageous to prevent traffic accidents.

On the other hand, the insulating asphalt concrete of the present invention uses a mixed aggregate containing waste vinyl aggregate, thereby providing a recycling means of waste vinyl, it is possible to prevent waste of petroleum resources. In particular, there is an advantage that the waste vinyl generated in the rural can be used for recycling as it is attached to the soil component.

1 schematically illustrates a process for producing waste vinyl aggregate of the present invention.
2a to 2f are photographs of each step in the manufacturing process of the waste vinyl aggregate produced in the embodiment of the present invention.
3 is a graph showing the change in thermal conductivity according to the content of waste vinyl aggregate in the asphalt concrete prepared in the embodiment of the present invention.
Figure 4 is a photograph of the wheel tracking (Wheel Tracking) specimen manufacturing equipment.
Figures 5a, 5b and 5c is a beaker containing ice on the insulating asphalt specimen prepared by using a mixed aggregate of the waste vinyl content of 1, 5 and 10% by weight, respectively, the ice melting rate after a certain time Measured pictures.

The present invention provides an insulating asphalt concrete prepared by mixing 1 to 10 parts by weight of the asphalt binder with respect to 100 parts by weight of the mixed aggregate of the general aggregate and waste vinyl aggregate of 80:20 to 99: 1.

General aggregate constituting the mixed aggregate of the present invention can be used for concrete road paving aggregates known in the art. For example, aggregates collected from rivers or at sea, crushed aggregates, etc. can be used without limitation. If necessary, recycled aggregates, for example, aggregates obtained by crushing waste concrete or brick may be used. There is no particular limitation as to the particle size, distribution of the aggregates, and the content of residual particles.

On the other hand, in the mixed aggregate of the present invention, the waste vinyl aggregate refers to the waste vinyl collected in the form of aggregate. Waste vinyl often occurs in a farm, but in the present invention, the waste vinyl does not necessarily have to be thrown away or left in the soil after farming, and may be used for industrial sites or households. The collected waste vinyl material is usually a polyethylene (PE) film including LLDPE and LDPE, but is not necessarily limited thereto. For example, in addition to the above material, a high density polyethylene (HDPE) film and a polyvinyl alcohol (PVA) film may be used. , Polypropylene (PP) film, and the like.

FIG. 1 schematically illustrates a process for producing waste vinyl aggregate of the present invention, and with reference to FIG. 1, the first step in the method for producing waste vinyl aggregate is to crush the collected waste vinyl to a certain size. It is a process. Next, the waste vinyl is melted and compressed at the same time by heating, and cooled to solidify in a granulated state. Finally, the compacted compacts are crushed to a certain size or extruded / cut into strands to obtain waste vinyl aggregate.

As another example of the method for producing the fevin aggregate, the method disclosed in Korean Patent No. 719136 may be applied. According to this method there is an advantage that the size of the pores formed in the aggregate can be arbitrarily adjusted.

The waste vinyl aggregate in the weight ratio up to 20% by weight of the total weight of the waste vinyl aggregate waste vinyl Soil components remaining at harvest may be included. When the content of the soil component contained in the waste vinyl exceeds 20% by weight, not only the melting is difficult but also uniform melting is difficult in the process of heat melting the collected waste vinyl.

When the amount of the soil component contained in the collected waste vinyl exceeds 20% by weight, the content is adjusted to 20% by weight through appropriate means, and then used to prepare the waste vinyl aggregate of the present invention. Controlling the content of the soil component may use a known means.

The waste vinyl aggregate is preferably 1 to 50mm in size. The size here means the longest diameter in the regular or irregular granular aggregate. When the size of the waste vinyl aggregate does not reach 1mm, there is a problem in that the strength does not appear, and when it exceeds 50mm, there is a problem in that it is not well blended with asphalt.

The waste vinyl aggregate may naturally include pores therein during the manufacturing process. The included pores enhance the thermal insulation of concrete produced using waste vinyl aggregates. If necessary regarding the pore, reference may be made to the technique disclosed in Korean Patent No. 719136 already mentioned.

On the other hand, the mixing ratio of the general aggregate and waste vinyl aggregate is preferably in the range of 80:20 to 99: 1 by weight. If the content of the waste vinyl aggregate exceeds 20% by weight, there is a problem that the asphalt binder should be increased to improve the strength of the waste vinyl concrete produced. On the other hand, if it does not reach 1% by weight, the effect of improving the strength and reducing the thermal conductivity is insignificant.

Insulating asphalt concrete of the present invention is prepared by mixing the above-described waste vinyl mixed aggregate and asphalt binder. At this time, the asphalt binder can be used is not particularly limited, natural or petroleum asphalt known in the art can be used, for example, straight asphalt, cutback asphalt, emulsified asphalt and the like can be used. Preferably straight asphalt, especially AP-5, AP-3, etc. can be used.

The content of the asphalt binder is preferably 1 to 10 parts by weight, more preferably 3 to 7 parts by weight, still more preferably 4 to 6 parts by weight, based on 100 parts by weight of the above-described waste vinyl mixed aggregate. Do. If the content of the asphalt binder does not reach 1 part by weight, the strength of the asphalt concrete produced due to the weak bonding strength of the mixed aggregates is insufficient for road paving. On the other hand, it is not preferable that the content of the asphalt binder exceeds 10 parts by weight because of problems such as reduced strength and plastic settling.

Hereinafter, the present invention will be described in more detail with reference to Examples. This is for explaining the present invention more specifically, but the scope of the present invention is not limited to these Examples.

Example

1. Obtaining Waste Vinyl Aggregate

(1) First, waste vinyl (80 to 90 wt% polyethylene film; 10 to 20 wt% soil component content) collected in rural areas is compressed, melted, cooled, and cut to use waste vinyl to produce concrete aggregate of the present invention. Got aggregate. Melting of the waste vinyl was carried out at a temperature of 160 to 170 ° C.

Figures 2a to 2f are photographs of the waste vinyl at each step in the manufacturing process of the waste vinyl aggregate produced in the embodiment of the present invention. In Figure 2,

(a) is a photograph of waste vinyl collected and loaded in rural areas,

(b) is a picture of the process of adding the waste vinyl to the shredder,

(c) a picture of the crushing and melting apparatus for the waste vinyl,

(d) is a photograph of the waste vinyl melted,

(e) is a photograph of waste vinyl before it is melted and solidified,

(f) is a photograph of the hardened waste vinyl. In the photograph 2 (f), it can be seen that pores are seen inside the solid waste vinyl.

(g) is a photograph of waste vinyl aggregate obtained by cutting solid waste vinyl to a size of 13 to 19 mm.

(2) The physical properties of the waste vinyl aggregate thus obtained were summarized in Table 1 below.

Item Experiment result Waste vinyl aggregate Other aggregate (reference value) importance 1.08 Gravel 2.5 ~ 2.7 Thermal conductivity of aggregate itself 0.092 (kcal / mh) Gravel 1.92, Sand 1.7 Wear rate
(LA wear test) 2.36% Gravel 35% or less: For paving
Gravel 40% or less: dam concrete Environmental hazards (leaching test results): No heavy metals detected / 0.92% oil component (5% environmental acceptance criteria)

As can be seen in Table 1, the waste vinyl aggregate used in the insulating asphalt concrete of the present invention has the advantage that the specific gravity and thermal conductivity is significantly lower as well as the wear rate is lower than the general aggregate.

2. Manufacture of Asphalt Concrete

The mixed aggregate is prepared by mixing the crushed aggregate and the waste vinyl aggregate in the ratio of weight ratio of 100: 0, 95: 5, 90:10 and 85:15, respectively, and then the asphalt (AP-5) binder is added to 100 parts by weight of the mixed aggregate. Insulating asphalt concrete was prepared by mixing at a ratio of 5 parts by weight.

The particle size distribution of the mixed aggregate including the crushed aggregate and waste vinyl aggregate is summarized in Table 2 below.

5% waste vinyl aggregate % Pass Residual amount (g) Residual rate (%) Aggregate size (mm) 26.5 97.5 30 2.5 19 82.5 120 10 13.2 55 330 27.5 4.75 42.5 150 12.5 2.36 24 222 18.5 0.6 15.5 102 8.5 0.3 11 54 4.5 0.15 6 60 5 0.075 0 72 6 Waste Vinyl Aggregate
(13 ~ 19mm) 60 5

3. Evaluation

(1) Thermal conductivity

Thermal conductivity was evaluated according to the QTM probe method, the results are summarized in Table 3 and FIG.

Waste Vinyl Aggregate Mixing Rate Thermal Conductivity (Kcal / mh ℃) Crushed 100% use asphalt mixture  1.76879 5% waste vinyl aggregate + 95% crushed stone mixed
Asphalt mixture 1.10249 10% waste vinyl aggregate + 90% crushed stone mixed
Asphalt mixture 0.91401 15% mixed waste vinyl aggregate + 85% crushed stone
Asphalt mixture 0.60662

In Table 3 and Figure 3, the asphalt concrete of the present invention has a thermal conductivity of 38%, 48% and 66%, respectively, compared to asphalt concrete using only crushed aggregates, although the waste vinyl aggregate content of mixed aggregates is only 5, 10 and 15% by weight. As a result, it can be seen that the thermal conductivity decreases significantly more than the simple loss of the crushed aggregate.

(2) Marshall stability

The Marshall Stability Test is one of the strength evaluation methods known in the art as one of the stability tests of the asphalt mixture. The disk-shaped specimens 10 cm in diameter x 6.3 cm in thickness were placed vertically, sandwiched between two upper and lower arc-shaped plates, and pressed at a constant speed of 50 mm for 1 minute, until the specimen was destroyed. The load and the corresponding deformation amount were measured (ASTM D 1559).

       Aggregate Mixing Ratio Marshall Stability (3 Test Averages)
(kg) Asphalt Binder Mixing Ratio Crushed 100% use asphalt mixture 1,101 5% Waste Vinyl Aggregate 5% + Crushed 95% Mixed Asphalt Mixture 2,314 5% Waste Vinyl Aggregate 10% + Crushed 90% Mixed Asphalt Mixture 2,817 5%

From Table 4, it can be confirmed that the asphalt concrete of the present invention using the mixed aggregate containing the waste vinyl aggregate significantly improved the Marshall stability compared to the case of using only crushed aggregate.

(3) Change of physical properties after freeze thawing

The waste vinyl aggregate mixed asphalt concrete is frozen in -18 ° C freezing chamber for 24 hours and then taken out, soaked in a constant temperature water bath at 60 ° C for 24 hours to melt, and then taken out. Tensile strength was measured using a universal testing machine (KS F 2398 Asphalt Resistance Test Method of Asphalt Mixture).

       Aggregate Mixing Ratio After freeze thawing
Tensile Strength (MPa) Asphalt binder
Mixing ratio Crushed 100% use asphalt mixture 1.390 5% Waste Vinyl Aggregate 5% + Crushed 95% Mixed Asphalt Mixture 2.565 5% Waste Vinyl Aggregate 10% + Crushed 90% Mixed Asphalt Mixture 2.474 5%

In Table 5, when the waste vinyl aggregate mixing ratio was 5% by weight, the tensile strength after freeze-thawing was significantly increased compared to when only 100% by weight of crushed stone was used, but when the waste vinyl aggregate was mixed at 10% by weight, 5% by weight would be mixed. It can be seen that the tensile strength after freeze-thaw decreases somewhat. This fact suggests that when the mixing ratio of the waste vinyl aggregate exceeds any limit, the mixing ratio of the asphalt binder must be further increased so that the mixing is good when the asphalt mixture is mixed, thereby increasing the overall strength.

(4) melting ice

a. Asphalt specimen preparation : After assembling the asphalt concrete of the present invention in a mold having a 30 cm x 30 cm x 5 cm in height ascon mixed with waste vinyl aggregate, using a wheel tracking specimen manufacturing equipment (see Fig. 4) While heating to 150 ° C., compaction was performed 15 times by applying a load of 500 kg, and compaction was performed 15 times while applying a load of 1,000 kg. The specimen prepared in this way was stored in an oven at 50 ° C. for 48 hours to maintain a constant temperature until the inside of the ascon specimen.

b. Ice (snow) melting experiment : After removing the asphalt specimen from the oven and leaving it at room temperature (13 ℃) for 30 minutes, moving it to the atmosphere of -0.3 ℃ temperature, and leaving it for another hour and 40 minutes, and then placed a beaker containing ice prepared in the freezer. It was placed on the asphalt specimen and the ice melting rate (quantity changed to water) was measured (see results 5a, 5b and 5c: waste vinyl aggregate contents 0, 5 and 10% by weight, respectively) in order.

c. Evaluation: The most of the ice in the beaker on the asphalt mixture specimens made of crushed aggregates was the lowest (lowest floor height of the water-changed part) and 5% by weight of waste vinyl aggregate, followed by 10% by weight. There was little left. In other words, when the waste vinyl aggregate is mixed with asphalt concrete, the thermal insulation effect is large (to preserve the warm warmth of the inside for a long time), thereby easily dissolving snow or ice accumulated in the winter. If the pavement is applied to the actual road, the warmth of the ground beneath the pavement will be preserved for a long time, and it will be advantageous to easily melt snow or ice accumulated on the pavement in winter and prevent traffic accidents.

Although the above has been described above with respect to preferred embodiments of the present invention, the present invention is not limited thereto, and it will be apparent to those skilled in the art that variations and modifications can be made in various forms within the scope of the technical idea of the present invention. It is obvious that the claims belong to the claims.

Asphalt concrete of the present invention is a road paving, in particular, the snow accumulated on the road surface in winter can be quickly removed, the road paving to prevent shrinkage tensile cracking or breakage due to Tokyo melting and summer heat island phenomenon (heat island) It can be used as a thermal barrier pavement to suppress city temperature rise.

Claims (4)

In the asphalt concrete prepared by mixing 1 to 10 parts by weight of the asphalt binder with respect to 100 parts by weight of the mixed aggregate of the general aggregate and the waste vinyl aggregate 80:20 to 95: 5,
The waste vinyl aggregate has a size of 5 to 50mm and includes pores formed therein,
The thermal conductivity of the concrete is an insulating asphalt concrete, characterized in that less than 1.2 Kcal / m · h · ℃. delete The heat-insulated asphalt concrete according to claim 1, wherein the amount of the soil component contained in the waste vinyl aggregate is 20% by weight or less of the total weight of the waste vinyl aggregate. 2. The insulating asphalt concrete of claim 1, wherein the Marshall stability is 2000 kg or more.

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