KR101030308B1 - Additive composition for an asphalt mixture and an asphalt mixture lmproved by addition of additive composition - Google Patents

Abstract

PURPOSE: An additive composition for an asphalt mixture is provided to enhance plastic deformation and resistivity to water damage through an optimal blending design of a reformed asphalt mixture. CONSTITUTION: An additive composition for an asphalt mixture comprises 56~64 weight% of waste tire fine powder, 28~36 weight% of low density polyethylene fine powder, 3 weight% of compatibilizers, 4.5 weight% of carbon black, and 0.5 weight% of PE WAX as a dispersing agent. A reformed asphalt mixture is formed by adding 0.5~1.5 weight% for the additive composition for reforming to a normal asphalt mixture.

Description

Additive composition for asphalt mixture and modified asphalt mixture to which the composition is added

The present invention relates to an additive composition for asphalt modification added to an asphalt mixture and a modified asphalt mixture to which the additive composition is added. Specifically, an optimal asphalt mixture composed of coarse aggregates, fine aggregates, fillers, and asphalt is specifically designed as asphalt mixture. As an additive composition for asphalt modification, the additive composition is composed of waste tire fine powder having a particle size of 80 to 300 mesh, fine powder of LDPE (low density polystyrene) having a particle size of 150 to 300 mesh, carbon black, a compatibilizer, and a dispersant. And a modified asphalt mixture wherein the composition is added to a conventional asphalt mixture.

Currently, invasion standards are applied to asphalt pavement grades and quality standards. However, in the case of asphalt pavement designed using asphalt that meets this standard, pavement damage such as plastic deformation and low temperature cracking occurs continuously due to summer temperature rise, explosive traffic volume, and congestion zone due to extreme weather. The reality is that the durability is getting shorter. As asphalt penetration test is conducted only at 25 ° C, there is a disadvantage that it is impossible to grasp the asphalt behavior at high temperature above 60 ° C, which is the asphalt pavement temperature at which plastic deformation occurs, or the low-temperature elastic behavior to predict the performance at low temperature. . Therefore, if asphalt is applied as it is, the quality of asphalt mixture is limited.

As asphalt is a viscoelastic material that is viscous at high temperatures and elastic at low temperatures, asphalt should be selected in consideration of roads where severe weather conditions and traffic, speed, and shear forces occur. It is reported that there is a fundamental problem because it is not satisfied.

As a way to solve this problem, the United States has proposed asphalt compatibility grade. General asphalt (AP-5), which meets the asphalt grade standard, has been subjected to the asphalt compatibility grade test of Korean Industrial Standard KS F 2389 (2004) as an asphalt grade standard considering environment, traffic, and long-term commonality. Asphalt compatibility grade (PG) test was applied to the modified asphalt binder containing (multi-Polymer Asphalt Modified additive (PAMA)), and the modified asphalt added to the modified additive of the present invention was compared with the PG standard. Asphalt mixture additive composition which can fully satisfy the quality of 76-22 or more.

Asphalt common grade standard is to select suitable asphalt according to local characteristics considering weather and traffic conditions of site to resist plastic deformation and pavement damage of low temperature crack. According to), it is recommended to use asphalt with a certain grade or higher in the section with high risk of plastic deformation because it is difficult to properly reflect high temperature resistance characteristics.

In particular, the application of asphalt grades of PG 76-22 or higher is considered to be applied to signal traffic areas of high traffic intersections, uphill sections, roads with heavy designations, and areas with high risk of plastic deformation due to heavy load traffic.

The beginning of the asphalt compatibility grade is the asphalt grade grade (PG), which consists of a binder test method of the Super Pave (Superior Performance Asphaet Pavement) system developed through the US Strategic Highway Research Program (SHRP). As the asphalt pavement quality of the site applied after the establishment of the public grade (PG grade) in the United States has been improved and evaluated very encouragingly, the modifier of the asphalt mixture of the present invention also satisfies the quality of the asphalt common grade PG 76-22 or higher, and is modified using the same. The modified additive composition of the asphalt mixture and modified asphalt mixture to which the composition is added can be provided based on the optimum blending design of the asphalt mixture, thereby improving plastic deformation and water damage resistance than the general asphalt mixture.

Modified asphalt, which is emerging to suppress plastic deformation of asphalt, generally improves the physical properties of asphalt by adding a certain amount of modifier to the existing asphalt. As plastic deformation of asphalt is mainly due to the breakage of asphalt road pavement at high temperatures, it has to have a higher viscosity at high temperatures, and research has been reported that a polymer is most suitable as a modifier to compensate for this problem. Modified asphalt used in Korea includes SMA (Stone Mastic Asphalt), SBSPMA (Styrene Butadiene Styrene Polymer Modified Asphalt), CRM (Crumb Rubber Modifier), PBS (Phoenix Bituminous Stabilizer), etc. Research on modified asphalt has been actively conducted.

On the other hand, the discovery and application of environmentally friendly and recyclable materials under the recent low carbon green growth have been studied in the field of asphalt concrete pavement. Studies on modified asphalt using industrial by-products include evaluation of the indoor properties of sulfur-modified modified asphalt mixtures (Yang, Sung-rin et al., 2006), and plastic deformation and peel resistance properties of CRM-modified asphalt mixtures (Do Young-su, 2007), Influence of Process Conditions on Physical Properties of Waste Tire Rubber Powder Modified Asphalt (Oh Kwang-jung et al., 2008), A Study on the Plastic Strain and Deformation Strength Characteristics of SMA Mixtures Using Waste Tire Powder (Hyun-Hwan Kim, 2009), R-EPDM Modified Asphalt Various studies have been conducted on asphalt mixtures using industrial by-products as modifiers such as plastic deformation and water-sensitive properties (Jo Young-jin et al., 2010).

Looking at the technical content of the domestic patent registration as a more specific conventional technology related to the present invention, the domestic registered patent publication (Registration No. 10-629902), "Asphalt paving epoxy resin composition and epoxy asphalt pavement mixture using the same" The technical contents of the are introduced.

The technical composition is composed of epoxy resin composition added to a conventional asphalt mixture consisting of large aggregates, fine aggregates, fillers, and asphalt, and asphalt pavement mixtures containing such thermosetting polymers such as epoxy resins. It is made by mixing two liquid components, which are curing agents, which react to form a strong three-dimensional structure.

Epoxy resin constituents mixed with asphalt exhibit modified thermoplastic properties rather than asphalt properties.

The difference between the thermoplastic asphalt and the thermosetting binder will limit the service life of the binder when mixing the two components of the thermosetting binder. In other words, the useful time depends on the temperature, and the higher the temperature, the shorter the time. After applying the thermosetting product, the increase in strength continues to increase with time, such as an organic-manganese compound, whose curing degree is changed according to the ambient temperature. . As the temperature increases, the asphalt softens and becomes more fluid.

Thermosetting binders are not sensitive to temperature and are hardly affected by a certain temperature, and have strong strengths in materials such as solvent oil and oil, but have a short service life of the binder and lack of viscoelasticity.

In another conventional technology, Korean Patent Publication (Registration No. 10-937181) relates to a bicycle bicycle pavement composition, which is prepared by mixing a synthetic resin selected from a low viscosity MMA resin, a thermosetting resin, or a rubber dispersed high viscosity MMA resin. It is difficult to apply the asphalt pavement grade and common grade standard according to the invasiveness standard because it uses various synthetic resin composition instead of asphalt which is commonly used as a binder for bicycle road pavement. However, various thermosetting synthetic resins are used, so as in the prior art mentioned above, shorter lifespans and short viscoelasticity may occur as binders, and a non-uniform mixture may be produced. Thus, the road pavement is modified on an asphalt mixture based on asphalt as a binder. Add additive Standing rating standard and modified asphalt additive composition in the rating criteria to satisfy the commonality of asphalt is preferred.

The present invention can secure the quality standards of asphalt common grade PG 76-22 or more by dramatically improving plastic deformation, pavement damage due to moisture damage, low temperature cracking, etc., which are problems of ascon pavement, by adding to conventional asphalt mixtures that are optimally designed. The present invention provides an additive composition for an asphalt mixture and an asphalt modified mixture to which the additive composition is added.

The present invention is 100-% by weight of the optimally designed conventional asphalt mixture consisting of coarse aggregate, fine aggregate, filler material, asphalt, 57-66 wt% of waste tire fine powder of average particle size 80-300 mesh, low density of 150-300 mesh average particle size. Asphalt compatibility by obtaining an additive composition for asphalt modification consisting of 26 to 35% by weight of polystyrene (LDPE) fine powder, 4.5% by weight carbon black, 3% by weight compatibilizer, and 0.5% by weight dispersant. Modified asphalt mixtures with grades above PG 76-22 can be obtained.

Asphalt modifier additive composition for adding asphalt mixture according to the present invention has excellent dynamic stability of Marshall stability when added to conventional asphalt mixture designed to be optimally designed and has a suitable flow value and high indirect tensile strength and tensile strength ratio. It can be referred to as asphalt modified additive composition and modified asphalt mixture which can secure the quality of asphalt common grade PG 76-22 or higher by drastically improving plastic deformation, pavement damage due to moisture damage, and low temperature cracking.

The modified additive according to the present invention is an asphalt modifier added to the asphalt mixture of general asphalt (AP-5) and synthetic aggregate, and the composition ratio of the optimum modifier is shown in Table (1).

          Composition ratio of asphalt modification additive composition. Unit: wt% Item Composition ratio Function

Waste Tire Fine Powder

56-64 о Average particle size 80 ~ 300 mesh
о Asphalt viscosity increase
Increased adhesion between asphalt and aggregate
о Increased ascon mixture stiffness
о Filling of voids in ascon mixture
о Increase the elasticity of the mixture
Low Density Polystyrene (LDPE) Fine Powder
28-36 о Average particle size 150 ~ 300 mesh
о Increased interstitial ascon mixture
(Increased plastic deformation resistance)
о Asphalt temperature desensitization
(Temperature crack resistance increase)
о Increased adhesion as a binder Compatibilizer (Modified Olefin Resin: NB 1600PE) 3 о Adhesive resin function
increase material compatibility
(Increase binder adhesion performance)
Carbon black
4.5 о Recovery effect of aging performance of waste tires
о Restore rubber properties
о Improve PG rating Dispersant (PE WAX) 0.5 о Maximize the dispersion effect of the modifier

In addition, the optimum modified asphalt mixture according to the present invention is a modified asphalt mixture obtained by adding 0.5 to 1.5% by weight of the modified additive composition shown in Table (1) to the asphalt mixture of general asphalt (AP-5) and synthetic aggregate. PG 76-22 is a modified asphalt mixture with excellent quality.

Rubber resin polymers (CRM, waste tire fine powder), thermoplastic resin polymers (LDPE fine powder), and carbon black of fine powder, dispersant and adhesive resin which are compatibilizers were used. The modified additive developed in the present invention may be referred to as modified asphalt (PAMA) modified with two or more composite polymers rather than one polymer resin that is generally used.

CRM, which is a rubber-based resin polymer that is used in the largest amount of the modifier, that is, the waste tire fine powder is a raw rubber powder that is used to recycle waste tires for vehicles. In general, asphalt with added waste tires has higher viscosity at high temperatures and lower stiffness at low temperatures than general asphalt (AP-5). Maintaining high viscosity at high temperatures is resistant to high stresses and deformations caused by traffic loads. The large force suppresses the occurrence of plastic deformation, and the low stiffness at low temperatures increases the resistance to temperature cracking. The waste tire fine powder used in the present invention used fine powder having an average particle size of 80 mesh (180 μm) to 300 mesh (85 μm). If the average particle size is larger than a certain size range, the expansion of CRM particles filling the pores of the asphalt mixture may not serve as a rubber-based resin polymer. Of course, the reforming work for the asphalt compatibility rating test is also difficult, and there is a difficulty that the test is not performed. On the other hand, if the average particle size is smaller than a certain size, there is an advantage that the modified asphalt mixture can be mixed with asphalt to obtain an early reforming effect, but deterioration of work environment and cost increase due to the volume and scattering of CRM fine powder Due to this, there is a disadvantage that a problem about economics occurs. Next, the LDPE micropowder, which is the thermoplastic resin polymer, which takes up the most weight, should also be used after appropriately reprocessing the average particle size. LDPE fine powder having an average particle size of 150 mesh (170 μm) to 300 mesh (85 μm) is preferably used. If the average particle size is larger than the average particle size, miscibility with asphalt is lowered. On the contrary, if the average particle size is smaller than the average particle size, problems related to economic efficiency due to deterioration of storage and work environment and an increase in production cost will be generated.

Low density polyethylene (LDPE) is a semi-crystalline polymer having a density of about 0.91 to 0.93 among ethylene polymers. Excellent heat adhesion and cold resistance hardly lose ductility at -50 ℃. Once melted, it is one of general purpose resins (LDPE, HDPE, PVC, PP, PS) with good chemical stability and high tensile strength because it has no big change in viscosity. Carbon Black, which plays a role of restoring and stabilizing the fine properties of the fine powder and maintaining the black color of the asphalt mixture, industrially collects soot produced by incomplete combustion of natural gas and tar, They are produced by pyrolysis. Currently 85% of the consumption is used for rubber, it is suitable that the particles do not have a fine chain-like bond, it is used to give properties such as enhancer, oil resistance, heat resistance. In the present invention, PE Wax 3% was used as a dispersant to improve the dispersion of the modifier. PE (Polyethylene) Wax is a material made by polymerizing ethylene, and the polymerization is carried out to an intermediate stage. PE Wax is classified into two types of LD type (Homopolymer, Oxidized Homopolymer) and two types of HD type (High Density Oxidized Homopolymer, Copolymer), and HD (High Density) and LD (Low) according to the high and low molecular weight Density). In this study, 3% PE Wax was used to maximize the dispersion effect. In addition, the reforming additive developed through the present invention used a compatibilizer to improve the adhesion between asphalt and aggregate, each of the modifiers.

Olefin resins have the advantages of low cost, excellent mechanical and chemical properties, and easy processing, while olefin resins are non-polar polymers (nylon, EVOH, PET, etc.), aggregates, aluminum, iron, paper, etc. When mixed with each other due to poor compatibility and adhesion with the polar substrate, there is a problem of deterioration of physical properties and lack of adhesion. The additive that maximizes the adhesion by increasing the compatibility with each of these materials can be said to be a compatibilizer (modified olefin resin with good adhesion).

Asphalt mixture of general asphalt (AP-5) and synthetic aggregate, which is applied to the present invention, is an asphalt mixture which is the most important basis for modified asphalt mixing design, and the physical properties of synthetic aggregate and used aggregate are used here. It is as Table (2) and Table (3), respectively.

Synthetic aggregate for asphalt mixtures. Agg ＼ Sieve Size (mm) Grading (mm) / Percentage of passing weight (%) 20 13 10 5 2.5 1.2 0.6 0.3 0.15 0.08 13 mm 100 98 53 8 2 - - - - - Crushed sand - - 100 90 71 49 34 17 8 4 Filer - - - - - - 100 99 95 84

Properties of Aggregate for Asphalt Mixtures. Item ＼ Classification 13 mm Crushed sand F.M 6.32 3.24 Density (g / cm 3) 2.67 2.64 Absorption (%) 1.0 1.4 Abrasion (%) 16 - Stability (%) Na ₂ SO ₄ 4 4 Unit Weight (kg / L) Rodding procedure 1.56 1.69

The coarse aggregate and fine aggregate for asphalt mixture of Table 2 are crushed aggregate produced by crushing general crushed stone which satisfies the quality standard of KS F 2357 (2009) which is the Korean industrial standard for aggregate for asphalt mixture. It is durable and has a proper particle size, and contains no soil, mud, dust, thin or long stone chips or other harmful substances. The filling material complies with the provisions of KS F 3501. Limestone or cement material is 1% or less of moisture.

Table (3) shows the results that satisfy the formulation design quality criteria. The mixing design process for the determination of the optimal asphalt content was carried out.

Aggregate granularity of 13mm products for modified asphalt road pavement surface is based on 13mm mixture WC-1 specified in the asphalt mixture production and construction guidelines of the Ministry of Land, Transport and Maritime Affairs (2009) and the heating asphalt mixture of Korean Industrial Standard (KS F 2349: 2010). The graph of aggregate granularity for modified asphalt (PAMA) mixture 13mm is shown in Figure 1 below.

(Figure 1)

Graph of Aggregate Granularity for Modified Asphalt Mixture 13 mm.

In addition, the mixing design for the modified asphalt road pavement surface 13 mm was carried out in consideration of the optimum mixing performance required to apply the modified asphalt mixture (PAMA) to the available products. The graph for determining the optimum asphalt content is shown in Figure 2 below.

(Figure 2)

Graph of optimum asphalt content determination.

The quality of modified asphalt mixtures has many quality characteristics in terms of their functional properties, but Marshall stability (MS) as defined in Korean Industrial Standard (KS F 2349: 2010) or Ministry of Land, Transport and Maritime Asphalt Mixtures (2009). ), Flow value (V), porosity (VTM), saturation (VFA), aggregate porosity (VMA), and additionally, dynamic stability (DS) and resistance to moisture damage to determine plastic deformation. Indirect tensile strength (ITS) test and tensile strength index (TSR) using it.

In addition, based on the optimum blend design results, the modified additive composition developed for application to the modified asphalt mixture in the present invention, that is, rubber and thermoplastic resin (LDPE) polymer, dispersing agent (PEWAX), carbon black and a common asphalt by mixing a compatibilizer Experimental results and formulation design of the modified asphalt mixtures prepared by AP-5) were analyzed.

The formulation design results for the modified asphalt mixture are shown in Table 4.

Combination design results for modified asphalt.
Item ＼
Modified asphalt
Remarks
AP-5
(0%) 0.5% 1.0% 1.5% 2.0% A Ltd
(1.0%) OAC (%) 5.7

Guidelines for the Production and Construction of Asphalt Mixtures (2009)
(Ministry of Land, Transport and Maritime Affairs)
Heating asphalt mixture
(KS F 2349: 2010)
(Korean industry standard) MS (N) 8 058 8 268 9 482 9 205 8 596 9 202 Flow
(1/100 cm)
34
32
30
35
42
30 VTM (%) 4 4 5 5 6 5 VFA (%) 74 74 72 71 69 72 VMA (%) 17.2 17.2 17.5 17.9 18.2 17.5 ITS (Mpa) 0.89 0.94 1.12 1.07 0.98 1.10 TSR 0.75 0.76 0.79 0.78 0.76 0.78 DS
(pass / mm)
1 253
2 152
3 264
2 925
2 423
3 150

The optimal formulation design is to use modified asphalt mixture roadway pavement material to obtain modified asphalt mixture products that have good resistance to plastic deformation and cracking and durability, and satisfy the required criteria. The optimal formulation should be determined to maintain performance. It should not only satisfy the quality standards of general asphalt (AP-5) mixtures, that is, general heated asphalt mixtures, but also the asphalt products of modified asphalt (PAMA). ) The quality performance is better than that of the mixture, and careful consideration must be made to fully exhibit the quality performance of the modified asphalt (product of A company) which is commercially available.

As a result of evaluating the quality performance of the modified asphalt mixture (PAMA) mixture developed in the present invention, MS (Marshall stability), Flow (flow value), and VTM (saturation), VFA (aggregate porosity) which can evaluate the flow resistance empirically All of the items satisfied the mixing regulations, and the results of plastic deformation and water damage resistance were remarkably superior to those of ordinary asphalt (AP-5) mixtures. The results were superior to those of general modified asphalt.

In order to evaluate the plastic deformation resistance of the modified product (PAMA) mixture, Marshall stability, recovery modulus and repeated driving tests were performed to analyze the results.

As shown in Table 5, based on 1% of the amount of the modifier added in the present invention, the MS measured value increased to 17.7% and then decreased. This is believed to be the result of a decrease in MS due to an increase in the CRM content of the modifier in the total asphalt mixture weight. When the amount of the modifier additive was 2%, the flow value was slightly excessive. The modified asphalt mixture of A company, which is a commercial product, also showed a 14.2% increase from general asphalt (AP-5), and the addition amount was 1% of the total mixture weight in the amount recommended in its specification.

Therefore, the MS performance of the modified asphalt mixture (PAMA) developed through the present invention showed a significantly larger value than that of the general asphalt (AP-5) mixture, and the results of the MS performance of the commercially available modified asphalt mixture.

It is considered that the amount of the modifier additive used within the range of 0.5% to 1.5% of the total weight of the asphalt mixture is preferable for the quality performance.

Marshall stability (MS). Item PAMA A company 0% 0.5% 1.0% 1.5% 2.0% 1.0% MS (N) 8 058 8 268 9 482 9 205 8 596 9 202 Increasing rate (%) - 2.6 17.7 14.2 6.7 14.2

Figure 3 below shows the trend of MS and Flow according to the modifier content. It shows the highest MS at 1% of addition amount, and the flow value increases as it exceeds 1.5%.

(Figure 3)

Trend graph of MS and Flow by modifier content.

As the most reliable test method for evaluating the plastic deformation resistance of the asphalt mixture, the cyclic driving test, that is, the wheel tracking test, was performed by the wheel load, and the results are shown in Table 6.

As a result of the repeated driving test, there are dynamic stability (DS) and strain rate (RD), and it is known that the greater the dynamic stability, the greater the resistance to plastic deformation. The DS of the modified asphalt mixture (PAMA) was increased by 71.7% than that of the general asphalt (AP-5) mixture, and increased by 160.5% according to the content of the modifier. The A company also showed a high growth rate of 151.4%, and the amount of the modifier added was similar to the trend of MS change. The results were much higher than the standard value prescribed for the surface layer of heated asphalt mixture in the Korean Industrial Standard (KS F 2349). If the DS of the conventional modified asphalt mixture is 200O (times / mm), the developed product is over 63%. Showed high results.

There was almost no difference according to the modified additive addition ratio of the modified asphalt (PAMA) mixture. When the addition ratio was 8%, the dynamic stability increased by 19% and the deformation rate decreased by 7%. Accordingly, it was found that the plastic deformation resistance of the modified asphalt (PAMA) mixture was better than that of the general asphalt (AP-5) mixture.

Dynamic degree. Item PAMA A Ltd 0% 0.5% 1.0% 1.5% 2.0% 1.0% DS (pass / mm) 1 253 2 152 3 264 2 925 2 423 3 150 Increasing rate (%) - 71.7 160.5 133.4 93.4 151.4

The strain calculated by the depth of settlement, one of the results of the repeated driving test, decreased up to 61.5% as the DS increased, and the A company also decreased by 60.3%. It can be seen that the results of DS and RD quality performance of the commercially modified asphalt as a commercial product.

The graph of the change trend of DS and RD according to the amount of modifier added is shown in Figure 4. It can be said that the resistance to plastic deformation at high temperature is much higher than that of general asphalt (AP-5).

(Figure 4)

Graph of DS and RD change with addition of modifier.

In addition, indirect tensile strength (ITS) is one of the important physical properties in evaluating the crack resistance of the pavement, in the present invention was measured the failure load and the displacement amount in the indirect tensile strength test at room temperature. Unlike the MS test, the measurement process indirectly measures the tensile strength by cutting specimens, and the test results are shown in Table 7.

Indirect tensile strength test. Item PAMA A Ltd 0% 0.5% 1.0% 1.5% 2.0% 1.0% ITS (MPa): Dry Condition 0.89 0.94 1.12 1.07 0.98 1.10 Increasing rate (%) - 5.6 25.8 20.2 10.1 23.6

As shown in the results of Table 7, ITS was increased by the amount of additives compared to general asphalt (AP-5), and the additive content was increased from 1% to 25.8% by 2% compared to 23.6% of commercial A company. Showed high results.

ITS is measured by cleavage by acting on a cylindrical specimen a static compressive load acting in parallel along a vertical diameter plane. The ITS results measured by these test methods are used to assess the likelihood of cracking of asphalt mixtures, and the tensile strain at break is useful for predicting the time of cracking. Thus, a mixture that can withstand high strains prior to failure means more resistance to cracking than a mixture that is not.

The ITS results of the modified asphalt mixture (PAMA) developed through the present invention showed significantly higher results than the general asphalt mixture, and it can be confirmed that the resistance to cracking is large by showing more than the performance of the commercially available modified asphalt mixture.

In the ITS measurement, the resultant ratio after room temperature and immersion is called a tensile strength index, that is, TSR. In the present invention, the test was conducted according to the provisions of the test method for water resistance of asphalt mixture (KS F 2398: 2005). Table 8 shows.

Tensile strength index test results. Item PAMA A Ltd 0% 0.5% 1.0% 1.5% 2.0% 15% TSR 0.75 0.76 0.79 0.78 0.76 0.78 Increasing rate (%) - 1.3 5.3 4.0 1.3 4.0

Six specimens with the same porosity were prepared, three were measured for ITS at 25 ° C, and the other three were immersed at 60 ± 1 ° C for 24 hours in a 25 ± 1 ° C constant temperature bath for 2-3 hours. ITS was measured after immersion. As shown in Table 8, it increased from 1.3% to 5.3% compared to general asphalt (AP-5), and the A company also showed a high TSR result with a 4.0% increase. The trend of TSR results according to the amount of modifier added is shown in Figure 5.

The low TSR means that the asphalt mixture is damaged due to moisture damage such as stripping and disintegration. The TSR of the modified asphalt mixture (PAMA) developed through the present invention was the highest at 1%, which can be said to be the optimum amount of modifier additive, and was 1.3% higher than the commercial A company. It can be seen that the developed product has excellent resistance to water damage.

(Figure 5)

Graph of ITS and TSR change according to the amount of modifier added.

As described above, the present invention relates to the development of modified asphalt mixture (PAMA) applying modified additives and the development of modified asphalt mixture products using the same as binders, and the plastic deformation at high temperature of general asphalt (AP-5) mixture road pavement products. And to reinforce the vulnerability due to moisture damage. In addition, a comparative experiment as a binder with a modified asphalt mixture, a commercial product of A, which is currently being constructed at a road pavement construction site, and a performance test as a mixture were performed to analyze the results.

Quality performance experiments were carried out on modified asphalt and mixtures developed by mixing rubber and thermoplastic resin polymers, carbon black, dispersants, and compatibilizers, which are predetermined functional additives, with general asphalt (AP-5). The same result was obtained.

1. Asphalt compatibility grade (PG) test results show that the modified additives can significantly improve the adhesion performance as a binder of general asphalt (AP-5), thereby improving the resistance to plastic deformation at high temperatures. It was. As a result of the comparative experiment as a binder with a commercially available modified A company, the modified effect on the modified additive content of the asphalt asphalt grade of the modified asphalt developed through the present invention showed a PG 76-22 or higher quality performance result. It is believed that the resistance to plastic deformation is excellent by showing the effect of modifying the binder over the quality performance of the existing commercial products.

2. If the modified asphalt manufactured with the optimum composition ratio of the reforming additive is used in the dry mixing method of the plant, it is judged to be the optimal content at 1% of the total weight of the asphalt mixture and the quality when determining the amount of the reforming additive within the range of 0.5% to 1.5%. It was found that the performance is excellent.

3. The quality performance of the modified asphalt applied mixture showed the best quality performance at 1% of modified additive addition, and the resistance to plastic deformation and water damage at high temperature was significantly higher than that of general asphalt (AP-5). In addition, compared with the quality performance of the modified asphalt mixture of Company A, which is a comparative product, it is considered that the quality and competitiveness are sufficient, and the excellent quality as the modified asphalt and modified asphalt mixture was confirmed.

The modified asphalt (PAMA) binder and modified asphalt mixture product for pavement surface layer developed through the present invention shows an excellent modification effect compared to the conventional general asphalt (AP-5) mixture, and is a commercial product of modified asphalt and mixture related products. It can be said to be a modified asphalt and a mixture of modified asphalt that can exhibit more than the quality performance.

The production of modified asphalt mixtures can be produced by dry mixing in the field plant when the AP-5 mixture is produced and sold by Samsung Co., Ltd. It is considered that the utilization of the field construction can be further increased because it can be sufficiently utilized in the field requiring resistance.

Claims (6)

Modified additive for general asphalt mixture composed of 56-64 wt% of waste tire fine powder, 28-36 wt% of low density polystyrene fine powder, 3 wt% of compatibilizer, 4.5 wt% of carbon black, and 0.5 wt% of PE WAX as dispersant Composition. A modified asphalt mixture prepared by adding 0.5 to 1.5% by weight of the additive composition for reforming to a conventional asphalt mixture (heated asphalt mixture specified in KS F 2349). The modified additive composition for general asphalt mixture of claim 1, wherein the waste tire fine powder has a particle size of 80 to 300 mesh. The modifier composition of claim 1, wherein the low density polystyrene fine powder has a particle size of 150 to 300 mesh. The modifier composition of claim 1, wherein the compatibilizer is an adhesive olefin modified resin. 3. The modified asphalt mixture of claim 2, wherein the modified asphalt mixture is characterized by a quality performance of PG 76-22 or higher.