KR101871413B1 - Complex Reinforcing Material with Glass Fiber, And Recycled Asphalt Mixture Using the Same - Google Patents

Abstract

The present invention relates to a hybrid glass fiber composite reinforcing material which prevents damages of an existing asphalt concrete pavement road such as rutting, cracks, potholes or others, reduces costs and enables convenient construction; and a recycled asphalt mixture using the same. The hybrid glass fiber composite reinforcing material according to the present invention, as a glass fiber composite reinforcing material which is mixed together with an asphalt binder and aggregate to form an asphalt mixture, comprises: a first reinforcing material which is formed in the form of a rod having the length of 10 to 15 mm and the diameter of 2 to 3 mm by coating a bundle of glass fibers having the diameter of 20 to 100 μm and the length of 10 to 15 mm with a synthetic resin having a melting point of 105 to 115°C; a second reinforcing material which is formed in the form of a rod having the length of 4 to 6 mm and the diameter of 2 to 3 mm by coating a bundle of glass fibers having the diameter of 20 to 100 μm and the length of 4 to 6 mm with the synthetic resin having the melting point of 105 to 115°C; and a third reinforcing material which is formed in the form of a cylinder having the diameter of 3 to 5 mm and the height of 3 to 5 mm by coating an industrial by-product powder with the synthetic resin having the melting point of 105 to 115°C.

Description

Technical Field [0001] The present invention relates to a hybrid glass fiber reinforced composite material and a recycled asphalt mixture using the hybrid glass fiber reinforced material,

The present invention relates to a reinforcing material to be mixed with an asphalt binder, and more particularly to a reinforcing material which is coated with synthetic resin on a glass fiber bundle cut with a predetermined length and coated with synthetic resin such as fly ash, And to a hybrid glass fiber composite reinforcing material capable of mixing a recycled aggregate and an asphalt binder to produce a recycled asphalt mixture.

In general, domestic road pavement mainly carries cement concrete pavement or asphalt concrete pavement (ascon), among which asphalt concrete pavement accounts for more than 90%.

Asphalt pavement has relatively low adaptability to heavy vehicles and frequent plastic deformation, cracks, and potholes due to relatively short life span due to frequent maintenance, which increases the cost of congestion. However, Speed and simplicity, and low maintenance, it is used in many places such as city roads.

If we look at the current state of road construction, the maintenance of existing roads is rapidly increasing rather than the construction of new roads. As a result, there is a shortage of natural aggregate required for the maintenance of existing roads and the problem of the treatment of waste asphalt concrete which occurs in the existing roads. Currently, most waste asphalt concrete is recycled for simple embankment and landfill. However, waste asphalt concrete contains aggregate and asphalt which can be reused for road pavement, .

Recycling of existing waste asphalt concrete technology has mainly improved the durability of the asphalt binder by adding renewable additives to the asphalt binder. However, when the mixing ratio of recycled aggregate increases, the durability of the asphalt mixture itself is improved There is a limit to doing.

Therefore, the aggregate of waste asphalt concrete is used for less than 25% of the total production weight, and it is used for roads with less traffic volume than main roads.

Korean Registered Patent No. 10-1494799 (Registered on February 12, 2015) Korean Patent Laid-Open No. 10-2009-0022835 (published on Mar. 4, 2009) Japanese Laid-Open Patent Publication No. 5-140464 (published Jun. 6, 1993) Japanese Patent Laid-Open No. 2008-189729 (Published on August 21, 2008)

It is an object of the present invention to provide a recycled asphalt mixture having excellent durability by mixing waste asphalt concrete produced during maintenance of existing roads with recycled aggregate, And a recycled asphalt mixture using the same.

Particularly, it is an object of the present invention to provide a hybrid glass fiber reinforced composite material which is cost effective and easy to construct while preventing rupture, cracking, and damage to a porthole of a conventional pavement of an asphalt concrete pavement, and a recycled asphalt mixture using the same.

In order to accomplish the above object, the hybrid glass fiber composite reinforcing material according to the present invention is a glass fiber composite reinforcing material which is mixed with an asphalt binder and an aggregate to form an asphalt mixture. The glass fiber composite reinforcement material has a diameter of 20 to 100 탆, Mm is coated with a synthetic resin having a melting point of 105 to 115 占 폚 to form a rod having a length of 10 to 15 mm and a diameter of 2 to 3 mm as a first reinforcing material; A second reinforcing material having a length of 4 to 6 mm and a diameter of 2 to 3 mm in the form of a bar by coating a bundle of glass fibers having a diameter of 20 to 100 탆 and a length of 4 to 6 mm with a synthetic resin having a melting point of 105 to 115 캜; And a third reinforcing material having a cylindrical shape with a diameter of 3 to 5 mm and a height of 3 to 5 mm by coating a synthetic resin having a melting point of 105 to 115 캜 on the industrial by-product powder.

The industrial byproduct powder constituting the third reinforcing material may be one or two types of fly ash having a silicon dioxide (SiO 2) content of 30 wt% or more and a 45 μm sieve residue of 40 wt% or less, ash, and bottom ash.

The synthetic resin of the first reinforcing material, the second reinforcing material and the third reinforcing material may be low density polyethylene (LDPE).

The low density polyethylene of the first reinforcing material is contained in an amount of 30 to 40 wt% with respect to the total weight of the first reinforcing material, and the low density polyethylene of the second reinforcing material is included in an amount of 30 to 40 wt% with respect to the total weight of the second reinforcing material Do.

The low density polyethylene of the third reinforcing material may be included in an amount of 40 to 50 wt% based on the total weight of the third reinforcing material.

The sum of the first stiffener and the second stiffener may be 30 to 60 wt%, and the remainder may be the third stiffener.

The present invention also provides an asphalt mixture comprising the hybrid glass fiber composite reinforcing material according to the present invention.

The asphalt mixture according to one aspect of the present invention comprises recycled aggregate made from waste asphalt concrete; New aggregate; And an asphalt binder.

The recycled aggregate may comprise at least 40 wt% of the total weight of the recycled asphalt mixture.

The glass fiber composite reinforcing material may be mixed with 0.5 to 2% by weight of the total weight of the recycled asphalt mixture.

According to the present invention, as the low-density polyethylene resin as the coating material of the reinforcing material is melted during the production of the asphalt mixture, the glass fibers are uniformly dispersed in the asphalt mixture, thereby increasing the meshing stress between the aggregates, The toughness of the mixture is increased and the viscosity increase effect of the asphalt binder due to the incorporation of the synthetic resin can be obtained. As a result, when the road construction is carried out using the recycled asphalt mixture according to the present invention, Hole breakage, etc., thereby improving the structural durability performance, and it is advantageous in reducing the usage amount of the new asphalt binder in the production of heated asphalt in the plant and in the economical efficiency due to the unused stone.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a constitution of a hybrid glass fiber composite reinforced material according to the present invention. Fig.
FIG. 2 is a graph showing the change in viscosity with the addition amount of a general asphalt binder (AP-3) and low density polyethylene (LDPE).
Figs. 3 and 4 are graphs showing the results of indirect tensile strength test of a general recycled asphalt mixture specimen (Comparative Example 1) and a recycled asphalt mixture specimen (Example 1) according to the present invention.
5A is a view for explaining a Hamburg wheel tracking test method for an asphalt mixture.
5B is a photograph showing a state in which a Hamburg wheel tracking test is performed on a general recycled asphalt mixture specimen (Comparative Example 1) and a recycled asphalt mixture specimen (Example 2) according to the test method shown in FIG. 5A .
6 is a graph showing the results of the Hamburg wheel tracking test for Comparative Example 1 and Example 2. FIG.
7 is a table showing results of dynamic elastic modulus tests for Comparative Example 1 and Example 1. Fig.
8 is a graph showing the dynamic modulus curve of the elastic modulus.
FIG. 9 is a graph showing the vertical axis of the dynamic elastic coefficient master curve shown in FIG. 8 converted to a logarithmic scale.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and it is to be understood that the invention is not limited to the disclosed embodiments.

Hereinafter, the hybrid glass-fiber composite reinforced material and the recycled asphalt mixture using the same will be described in detail with reference to the accompanying drawings.

1, the hybrid glass-fiber composite reinforced material according to the present invention comprises a plurality of first reinforcing materials 10 having a length of 10 to 15 mm and a diameter of 2 to 3 mm and a length of 4 to 6 mm, A plurality of second stiffeners 20 in the form of bars having a length of 2 to 3 mm, and a third stiffener 30 having a cylindrical shape with a diameter of 3 to 5 mm and a height of 3 to 5 mm.

The first reinforcing material 10 is a low density polyethylene (LDPE) having a melting point of 105 to 115 DEG C, a bundle of glass fibers 11 having a diameter of 20 to 100 mu m and a length of 10 to 15 mm, To have a rod shape having a length of 10 to 15 mm and a diameter of 2 to 3 mm.

Also, the second reinforcing material 20 may be a low density polyethylene (LDPE) having a melting point of 105 to 115 DEG C, a bundle of glass fibers 21 having a diameter of 20 to 100 mu m and a length of 4 to 6 mm, To have a rod shape having a length of 4 to 6 mm and a diameter of 2 to 3 mm. The second stiffener 20, which is made of relatively short fibers as compared to the first stiffener 10, acts to suppress short-term initial cracks that may occur in the asphalt mixture.

The first reinforcing member 10 and the second reinforcing member 20 have a structure in which a glass fiber bundle cut into a predetermined length range is coated with low density polyethylene (LDPE) having a melting point of 105 to 115 ° C., The low-density polyethylene is melted during the production of the mesophase asphalt mixture and the high-temperature asphalt mixture of 170 ° C or higher, so that the glass fiber can be uniformly dispersed in the asphalt mixture.

The low density polyethylene as a coating material of the first reinforcing material 10 is preferably 30 to 40% by weight based on the total weight of the first reinforcing material 10.

The low density polyethylene which is a coating material of the second reinforcing material 20 is also preferably 30 to 40% by weight based on the total weight of the second reinforcing material 20.

The third reinforcing material 30 is made of a synthetic resin such as low-density polyethylene (LDPE) having a melting point of 105 to 115 ° C coated on the industrial by-product powder to have a cylindrical shape with a diameter of 3 to 5 mm and a height of 3 to 5 mm . The industrial byproduct powder constituting the third reinforcing material 30 may be one or two types of fly ash having a silicon dioxide (SiO 2) component of 30 wt% or more and a 45 μm sieve fraction of 40 wt% or less, reject ash, bottom ash, and so on.

The low density polyethylene of the third stiffener 30 is preferably 40 to 50 wt% with respect to the total weight of the third stiffener 30.

The low density polyethylene which is a coating material of the third stiffener 30 is also melted in the process of preparing a mixture of a middle temperature asphalt mixture of about 130 캜 and a high temperature asphalt mixture of 170 캜 or higher. As the low density polyethylene is melted, the industrial byproduct powder is uniformly mixed in the asphalt mixture. Therefore, when the industrial by-product powder is coated with low density polyethylene and mixed, the industrial by-product powder can be uniformly dispersed and mixed over the entire asphalt mixture, rather than by mixing the industrial by-product powder alone with the asphalt mixture.

Industrial by-product powder constituting the third reinforcing material 30 increases the specific surface area to improve the adhesion strength between the asphalt binder and the aggregate, thereby improving the overall durability and strength. In addition, since the specific gravity is larger than that of uncoated powdered limestone, which is a conventional powdery anti-peeling material, there is an advantage that the asphalt mixture can be well dispersed upon dispersion. The third stiffener 30 serves to dramatically improve the stability of the asphalt mixture by replacing at least 50% of the quarry filler of the conventionally used asphalt mixture.

When fly ash, REJEC ash, or bottom ash having a silicon dioxide (SiO 2) content of 30 wt% or more and a specific gravity of 2.2 or more is used as the industrial byproduct powder of the third reinforcing material 30, Adhesion with the asphalt binder can be obtained.

The first reinforcing material 10, which is a long fiber reinforcing material, and the second reinforcing material 20, which is a short fiber reinforcing material, are arranged in multiple directions in the asphalt mixture to increase the long-term fatigue crack resistance and microcrack resistance of the asphalt mixture. 3 The reinforcing material 30 increases the specific surface area of the asphalt binder and the aggregate due to the incorporation of the fine powder, thereby preventing the asphalt mixture from being pushed or lifted due to the weakening of the adhesion performance.

The sum of the first reinforcing material 10 and the second reinforcing material 20 in the glass fiber composite reinforcing material is 30 to 60% by weight, and the remainder is made of the third reinforcing material 30.

As described above, the glass fiber composite reinforcing material composed of the first reinforcing material 10, the second reinforcing material 20 and the third reinforcing material 30 is mixed with the recycled aggregate made of the waste asphalt concrete, the new aggregate material and the asphalt binder Recycled asphalt mixture.

Since the recycled asphalt mixture of the present invention has the effect of improving the strength and durability by the glass fiber composite reinforcing material, the amount of the recycled asphalt mixture to be used can be minimized, The mixing ratio of the recycled aggregate can be adjusted to 40 wt% or more of the total weight of the recycled asphalt mixture.

Therefore, there is an effect that the amount of recycled aggregate can be greatly improved from about 25 wt%.

It is preferable that the glass fiber composite reinforcement material among the total weight of the recycled asphalt mixture is mixed at 0.5 to 2 wt%.

When low density polyethylene (LDPE) is used as a synthetic resin forming the coating material of the first reinforcing material 10, the second reinforcing material 20 and the third reinforcing material 30, the low density polyethylene of the asphalt mixture is melted and mixed, And the effect of the present invention can be greatly improved.

2 shows a result of viscosity test when 5 wt% and 15 wt% of low density polyethylene (LDPE) were added to a common asphalt binder AP-3, respectively. As shown in Fig. 2, the asphalt binder AP- ), The viscosity was 1,921 Poise. However, when 5 wt% and 15 wt% of low density polyethylene (LDPE) were added to the asphalt binder (AP-3) respectively, the viscosity increased to 4,338 Poise and 30,318 Poise respectively .

Example

The glass fiber composite reinforcement material including the recycled aggregate and the new aggregate, the filler material (limestone powder), the asphalt binder, and the first reinforcing material 10, the second reinforcing material 20 and the third reinforcing material 30 was mixed To prepare the test samples of Comparative Example 1 and Examples 1 and 2. The fabricated specimens were fabricated to meet the indirect tensile strength test, tensile strength test, Hamburg wheel trekking test and dynamic modulus test.

division Comparative Example 1 Example 1 Example 2 Ascon waste aggregate 13 mm or less 49.8 wt% 49.6 wt% 49.6 wt% New aggregate 13 mm or less 45.2 wt% 45.0 wt% 45.0 wt% Filler (limestone) 1.9 wt% 1.6 wt% 1.6 wt% Asphalt binder (AP-3) 3.1 wt% 3.1 wt% 3.1 wt% Glass fiber composite
Reinforcement material The first stiffener 0.0 wt% 0.1 wt% 0.3 wt% Second stiffener 0.0 wt% 0.3 wt% 0.1 wt% Third stiffener 0.0 wt% 0.3 wt% 0.3 wt% Sum 100 wt% 100 wt% 100 wt%

[Experimental Example 1] Indirect tensile strength test

(Comparative Example 1) in which the glass fiber composite reinforcing material was not mixed at all with the composition ratio shown in Table 1 (Comparative Example 1), and the first reinforcing material and the second reinforcing material as the glass fiber composite reinforcing materials according to the present invention , And the third reinforcing material (Example 1) were subjected to an indirect tensile strength test at an ambient temperature of 25 ° C.

Table 2 shows the results of the average indirect tensile strength and toughness of Comparative Example 1 and Example 1, and the average indirect tensile strength was about 1.4 times higher than that of Comparative Example 1. 3 and 4 are graphs showing the results of the indirect tensile strength test of the respective specimens. According to the test results, the maximum tensile strength and strain energy (the area under the curve in FIG. 2) of the specimen of Example 1 was the largest Respectively.

division Comparative Example 1 Example 1 Indirect Tensile Strength (MPa) 1.37 1.91 Toughness (N · mm) 9,464 10,935

The recycled asphalt mixture specimen (Example 1) in which the glass fiber composite reinforcing material of the present invention was mixed exhibited an effect of uniformly dispersing the glass fiber, thereby increasing the intergranular intermeshing stress and the toughness of the mixture due to the intergranular bridge effect As a result, when the road construction is carried out using the recycled asphalt mixture according to the present invention, problems such as plastic deformation, fatigue crack, and port hole breakage are solved, It has been confirmed that the asphalt production has a favorable effect in economical efficiency due to the absence of stones.

[Experimental Example 2] Tensile strength ratio (TSR) test

In order to confirm the moisture sensitivity of the recycled asphalt mixture prepared by mixing the glass fiber composite reinforcing material according to the present invention, the relative dryness of the completely dried sample and the freeze-thawed sample of Comparative Example 1 and Example 2 were compared. The freezing and thawing procedure of the experiment is to record the moisture saturation of the specimen using the moisture saturation formula and to saturate the specimen when the saturation is within 70 ~ 80% and when it is smaller than 70% Discard. Wrapped specimens with 70 ~ 80% saturation are wrapped and sealed with 10 ± 0.5 ml of specimen and water, and frozen in a freezer at 18 ± 3 ℃ for 16 h. After freezing, 24 ± 1h melted specimens are immersed in a bath of 25 ± 0.5 ° C for 2h ± 10min and then subjected to indirect tensile strength test. The moisture sensitivity is evaluated by the ratio of indirect tensile strength before and after freeze-thaw. Recycled asphalt using waste aggregate should satisfy 0.75 or more.

Table 3 shows the results of the tensile strength ratio test of the recycled asphalt composition using the ascone waste aggregate. The recycled asphalt mixture (Example 2) containing the composite reinforcement material was 0.77, which satisfied the criterion. The recycled asphalt mixture (Comparative Example 1) was 0.72 and was not satisfied with the standard.

division Comparative Example 1 Example 2 Dry Indirect Tensile Strength (MPa) 0.93 1.27 After freeze-thawing
Indirect Tensile Strength (MPa) 0.67 0.98 Tensile strength ratio (TSR) 0.72 0.77

In addition, the indirect tensile strength of the dried specimen was increased by 1.3 times as compared with that of Comparative Example 1, and the indirect tensile strength after freezing and thawing was increased by 1.4 times or more. This indirectly indicates that the glass fiber is effective when the resistance performance in the tensile direction is increased and the freezing and thawing is repeated by expressing the bridging effect of the glass fiber in the specimen of Example 2.

[Experimental Example 3] Hamburg wheel tracking test

In order to comprehensively confirm the plastic deformation resistance and water resistance increase characteristics of the recycled asphalt mixture of the glass fiber composite reinforcing material of the present invention, comparative comparison was carried out by the Hamburg wheel tracking test on the specimens of Comparative Examples 1 and 2 Respectively. In the Hamburg wheel-tracking test, as shown in Figs. 5A and 5B, the iron ring having a load of 158 lbs was placed on a circular specimen, and the load was continuously applied to measure the depth of plastic deformation according to the number of loads.

FIG. 6 is a graph showing the results of a Hamburg wheel tracking test in which water was immersed at 55 ° C. for 50 seconds at a rate of about 20,000 times for Comparative Example 1 and Example 2. According to the test result, The recycled asphalt mixture (Comparative Example 1) without any mixing of materials produced a plastic deformation depth of about 18 mm at about 11,000 times, and the recycled asphalt mixture (Example 2) About 17mm, which is about twice the resistance to plastic deformation.

[Experimental Example 4] A dynamic elastic modulus test

 The dynamic modulus test of the asphalt mixture evaluates each dynamic modulus of elasticity according to the combination of the test temperature and the load frequency. Each of the dynamic elastic moduli obtained from the experiment is determined by using the superposition principle of load time and temperature, and the change of dynamic modulus in the low temperature region (high frequency region) and the high temperature region (low frequency region) . The test specimens used for the test were cylindrical specimens with a diameter of 150 mm and a height of 160 mm by using a turning compaction machine and cored specimens with a diameter of 100 mm and a height of 150 mm were used as test specimens. The dynamic modulus of elasticity is obtained by placing cylindrical specimens (Comparative Example 1 and Example 1) in a chamber capable of temperature control and repeating stress of 241 kpa. The dynamic elastic modulus test in Experimental Example 4 was carried out at five test temperatures (-5 ° C, 5 ° C, 21 ° C, 40 ° C and 54 ° C) and seven loading frequencies (25, 10, 5, 1, 0.5, 0.01 Hz). The dynamic modulus of elasticity obtained in the test was as shown in the table of Fig. 7, and the dynamic elastic master curves of Figs. 8 and 9 were determined using the results.

FIG. 8 is a graph showing the dynamic elastic coefficient master curve as it is, and FIG. 9 is a graph obtained by converting the longitudinal axis of the dynamic elastic coefficient master curve into a log scale so as to observe the low frequency region band in detail. (Example 1) It can be confirmed that the dynamic modulus of elasticity is lowered in the high frequency region region (low temperature region) than in the recycled asphalt mixture (Comparative Example 1) in which the glass fibers are not mixed at all. The lowering of the dynamic elastic modulus in the high-frequency region (low-temperature region) means that it is resistant to cracking due to low temperature.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. And it is to be understood that such modified embodiments belong to the scope of protection of the present invention defined by the appended claims.

10: first stiffener 11: glass fiber
20: second stiffener 21: glass fiber
30: Third stiffener

Claims (10)

delete A glass fiber composite reinforcement material which is mixed with an asphalt binder and an aggregate to form an asphalt mixture,
A bundle of glass fibers having a diameter of 20 to 100 탆 and a length of 10 to 15 mm is coated with a synthetic resin having a melting point of 105 to 115 캜 to form a bar having a length of 10 to 15 mm and a diameter of 2 to 3 mm;
A second reinforcing material having a length of 4 to 6 mm and a diameter of 2 to 3 mm in the form of a bar by coating a bundle of glass fibers having a diameter of 20 to 100 탆 and a length of 4 to 6 mm with a synthetic resin having a melting point of 105 to 115 캜; And
A third reinforcing material having a cylindrical shape with a diameter of 3 to 5 mm and a height of 3 to 5 mm by coating an industrial by-product powder with a synthetic resin having a melting point of 105 to 115 ° C;
/ RTI >
The industrial byproduct powder constituting the third reinforcing material may be one or two types of fly ash having a silicon dioxide (SiO 2) content of 30 wt% or more and a 45 μm sieve residue of 40 wt% or less, ash, and bottom ash. The hybrid glass fiber reinforced composite material according to claim 2, wherein the synthetic resin of the first reinforcing material, the second reinforcing material and the third reinforcing material is low density polyethylene (LDPE). The hybrid glass fiber reinforced composite material according to claim 3, wherein the low density polyethylene of the first reinforcing material is contained in an amount of 30 to 40% by weight based on the total weight of the first reinforcing material. The hybrid glass fiber reinforced composite material according to claim 3, wherein the low-density polyethylene of the second reinforcing material is contained in an amount of 30 to 40% by weight based on the total weight of the second reinforcing material. 4. The hybrid glass-fiber reinforced composite material according to claim 3, wherein the low-density polyethylene of the third reinforcing material is contained in an amount of 40 to 50% by weight based on the total weight of the third reinforcing material. The hybrid glass fiber reinforced composite material according to claim 2, wherein the sum of the first reinforcing material and the second reinforcing material is 30 to 60 wt%, and the remainder is a third reinforcing material. The hybrid glass fiber composite reinforcing material according to any one of claims 2 to 7;
Recycled aggregate made from waste asphalt concrete;
New aggregate; And
Asphalt binder;
A mixture of recycled asphalt. The recycled asphalt mixture according to claim 8, wherein the recycled aggregate is at least 40% by weight of the total weight of the recycled asphalt mixture. The recycled asphalt mixture according to claim 8, wherein the glass fiber composite reinforcing material is mixed at 0.5 to 2% by weight of the total weight of the recycled asphalt mixture.

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