High-strength glass fiber reinforced rubber asphalt stress absorbing layer and preparation method thereof

Abstract

The invention discloses a high-strength glass fiber reinforced rubber asphalt stress absorption layer and a preparation method thereof, and belongs to the technical field of road engineering materials. By optimizing material components (rubber asphalt, glass fiber and basalt macadam) and a construction process (macadam premixing, high-temperature spraying and rolling forming), the interlayer bonding strength, the shear resistance and the low-temperature crack resistance are remarkably improved. Tests show that the stress absorption layer can reduce the occurrence rate of reflection cracks by more than 30%, the maintenance cost in the whole life cycle is reduced by 20%, the technical problems of low-temperature embrittlement, high-temperature softening, insufficient interlayer bonding and the like of a traditional stress absorption layer are solved, efficient prevention and control of the reflection cracks and long-term stability of pavement performance are achieved, and the service life of the pavement is prolonged. And the method has remarkable economic benefits and social benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, and particularly relates to a high-strength glass fiber-reinforced rubber asphalt stress absorption layer and a preparation method thereof. Background Art

[0002] Existing highway bases mostly adopt semi-rigid material bases (such as cement stabilized macadam). Their temperature shrinkage and dry shrinkage characteristics are prone to cause base cracking, and the cracks are reflected upward to the asphalt surface layer through the coupling action of load and temperature, forming reflective cracks. Traditional treatment technologies (such as increasing the surface layer thickness, optimizing the base design, laying graded crushed stone, etc.) can only delay the development of cracks and cannot fundamentally solve the problem of base deformation. Laying a stress absorption layer between the asphalt surface layer and the semi-rigid base can not only improve the bonding situation between the asphalt surface layer and the base, but also delay the development of cracks. When the stress is transmitted upward through the stress absorption layer, the stress will be dispersed and no longer concentrated at the base cracks. At the same time, due to the flexibility of the stress absorption layer itself, it will not break when affected by concentrated stress.

[0003] Although existing research shows that the rubber asphalt stress absorption layer has a good effect on treating reflective cracks in asphalt pavements and has outstanding interlayer bonding ability, its low-temperature toughness is poor, it softens severely at high temperatures, and its crack resistance performance is limited. Moreover, there are many domestic studies on single crushed stone spreading type stress absorption layers at present, but the asphalt premixing effect in the crushed stone spreading process is not good, which may lead to insufficient interlayer bonding force. Therefore, in recent years, laying an interlayer functional layer integrating crack resistance, waterproofing, and stress absorption between the semi-rigid base and the asphalt surface layer to enable the asphalt pavement structure to simultaneously have the abilities of crack resistance, waterproofing, and stress absorption has become the focus of traffic infrastructure construction research. The application of the stress absorption layer can greatly improve the quality of highway construction and reduce the maintenance cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength glass fiber-reinforced rubber asphalt stress absorption layer and a preparation method thereof to solve the problems in the background art.

[0005] To achieve the above purpose, the present invention provides a high-strength glass fiber-reinforced rubber asphalt stress absorption layer, which includes the following components: rubber asphalt, high-strength glass fiber, basalt crushed stone, and 70# matrix asphalt with an oil-stone ratio of 0.5%;

[0006] The rubber asphalt is obtained by compound modification of 70# matrix asphalt and waste rubber powder in a ratio of 1:0.18 - 0.22;

[0007] [[ID=2⑤]]The interlayer bonding strength of the stress absorption layer ≥ 0.5 MPa, and the maximum flexural tensile strain at -10 °C ≥ 3900 με.

[0008] Preferably, the length of the high-strength glass fiber is 3 - 12 cm, and the dosage is 120 - 180 g / m2.

[0009] Preferably, the particle size of the basalt gravel is 9.5 - 13.2 mm, and the spreading amount is 14 kg / m 2 .

[0010] The present invention also provides a preparation method of the above-mentioned rubber asphalt stress absorption layer reinforced by high-strength glass fiber, comprising the following steps:

[0011] Step 1. Material pretreatment

[0012] 1) High-speed shear mixing and stirring of waste rubber powder and 70# matrix asphalt to form a composite modified rubber asphalt;

[0013] 2) Airflow screening treatment of high-strength glass fiber to obtain high-strength glass fiber with a length of 3 - 12 cm;

[0014] Step 2. Semi-rigid material base treatment

[0015] Roughening the semi-rigid base and spraying a coal tar seal coat;

[0016] Step 3. Preparation of the stress absorption layer

[0017] 1) Premixing and spreading of gravel: Mix basalt gravel and 70# matrix asphalt with an oil-stone ratio of 0.5% evenly, and the spreading thickness is 2 - 3 cm;

[0018] 2) Spraying of rubber asphalt: Heat the composite modified rubber asphalt and spray it on the surface of the gravel to form an asphalt bonding layer;

[0019] 3) Sprinkling of glass fiber: Uniformly disperse high-strength glass fiber above the asphalt bonding layer to complete the laying of the stress absorption layer;

[0020] 4) Compaction and forming: Lay an asphalt surface layer above the stress absorption layer, and use a forming machine to roll and form the stress absorption layer.

[0021] Preferably, in Step 1, the mixing temperature of the waste rubber powder and 70# matrix asphalt is 107 - 190 °C; the stirring time is 30 min.

[0022] Preferably, in Step 3, the heating temperature of the composite modified rubber asphalt is 195 - 205 °C.

[0023] A high-strength glass fiber-reinforced rubber asphalt stress absorption layer and its preparation method provided by the present invention. To prove the performance of the rubber stress absorption layer, the present invention formed three types of composite sandwich specimens and conducted interlayer bonding performance, shear resistance performance, and low-temperature bending performance tests in combination with the actual characteristics of the road. The comprehensive performance of the high-strength glass fiber rubber stress absorption layer (Type A specimen), SBS stress absorption layer (Type B specimen), and modified emulsified asphalt tack coat (Type C specimen) was compared, and the following conclusions were obtained:

[0024] (1) Since the pull-out strength of the three stress absorption layers depends on the bonding force between the interlayer aggregate and the laid asphalt, the pull-out strength of the rubber stress absorption layer specimen is the largest, which is 0.51 MPa, and the pull-out strength of the modified emulsified asphalt specimen is the smallest, which is 0.18 MPa. The interlayer pull-out strength of the high-strength glass fiber rubber asphalt stress absorption layer is more than doubled compared with that of the modified emulsified asphalt. This is mainly because the rubber particles have good filling and thickening properties in the rubber asphalt, which can effectively fill and bond the voids in the asphalt mixture and improve the bondability of the asphalt mixture.

[0025] (2) As the shear angle increases, the failure load of the specimens gradually decreases, indicating that the greater the road slope, the easier it is to have shear failure. The failure load of the Type A specimen is 13.9% and 30.4% larger than that of the Type B and Type C specimens. The shear strength relationship curve of the rubber asphalt stress absorption layer is obtained, with the bond force being 0.58 MPa and the internal friction angle being 12.84°.

[0026] (3) The maximum flexural tensile strain of the specimens decreases as the temperature drops. The low-temperature bending ability of the Type A specimen is the best at three temperatures. Its maximum flexural tensile strain at -10°C can reach 3936 με, which is 23.7% and 113.3% higher than that of the Type B and Type C specimens. This is because the low-temperature creep progress modulus of the rubber asphalt is small, and it will not accumulate more internal forces when generating small deformations, so it is not easy to produce brittle failure. However, as the temperature decreases, the stiffness modulus increases, which is the reason why the flexural tensile strength of the specimen at -10°C is less than that at -5°C.

[0027] The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. Description of the Drawings

[0028] Figure 1 It is the shear strength curve of the Type A specimen prepared in the embodiment of the present invention. Detailed Embodiment

[0029] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent substitution methods and shall be included within the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application and belong to the protection scope of the present invention.

[0030] As used herein, the mention of "embodiment" means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The term "embodiment" that appears in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0031] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0032] Unless otherwise specified in the present invention, the reagents, instruments, equipment, etc. used are all the reagents, instruments, and equipment commonly used by those skilled in the art in this field.

[0033] The material specifications used below are shown in Table 1 as follows.

[0034] Table 1 Material Specifications

[0035]

[0036]

[0037] Embodiment

[0038] The embodiment provides a preparation method of a high-strength glass fiber-reinforced rubber asphalt stress absorption layer, including the following steps:

[0039] Step 1. Material pretreatment

[0040] 1) High-speed shear mixing and stirring of waste rubber powder and 70# matrix asphalt to form a composite modified rubber asphalt, where the proportion of waste rubber powder is 20%;

[0041] 2) Airflow screening treatment of high-strength glass fibers to obtain high-strength glass fibers with a length of 12 cm;

[0042] Step 2. Treatment of semi-rigid material base

[0043] 1) Molding of cement stabilized macadam base specimens

[0044] Place a 300mm×300mm×10mm elevation steel plate in the mold. According to the synthetic gradation of cement stabilized macadam in the skeleton dense gradation recommended by the current specification "Technical Rules for Construction of Highway Pavement Bases" (JTG / TF20-2015), add water, cement, and graded aggregates into a UJZ-15L type mixer for stirring. The stirring time is two minutes. After the mixture is fully stirred evenly, load the mixture into a single-layer rut plate mold, and use the static pressure molding method to form a cement stabilized macadam plate with a thickness of 4cm. Demold after 24h and perform surface grinding treatment, then send it to the standard curing room for standard curing for 28d.

[0045] 2) Laying the cement stabilized macadam base

[0046] Perform surface roughening treatment on the four sides of the cement stabilized macadam base that has undergone 28d standard curing. The size of the formed cement stabilized macadam is 300mm×300mm×40mm. Place it into the test mold of a double-layer rut plate, with specific dimensions of 300mm×300mm×100mm, and spray coal tar for sealing treatment.

[0047] Step 3. Preparation of stress absorption layer

[0048] 1) Pre-mixed aggregate paving: Mix basalt aggregates with a particle size range of 9.5mm - 13.2mm evenly with 70# matrix asphalt with an oil-stone ratio of 0.5%, which can effectively enhance its adhesion to rubber asphalt. Among them, the spreading amount of basalt aggregates is 14kg / m 2 , and the paving thickness is 2 - 3cm.

[0049] 2) Rubber asphalt spraying: Heat the composite modified rubber asphalt and spray it on the surface of the aggregates to form an asphalt bonding layer;

[0050] 3) Glass fiber spreading: Uniformly disperse 180g / m 2 of high-strength glass fiber above the asphalt bonding layer to complete the laying of the stress absorption layer;

[0051] 4) Compaction and molding: Lay an asphalt surface layer above the stress absorption layer, and use a QCX-4 rut specimen molding machine to roll and form the stress absorption layer. On the construction site, use a rubber-tyred roller to roll it back and forth until the area where the aggregates are wrapped by asphalt reaches more than 70%. In this case, the contact area between the asphalt and the aggregates is the largest, and the bonding effect with the underlying layer is the strongest.

[0052] The stress absorption layer is located between the semi-rigid base course and the asphalt surface course, mainly playing a role in crack resistance. Under the repeated action of vehicle loads, good interlayer bonding performance is crucial for its crack resistance effect. Since cracks are mostly generated and propagated in low-temperature environments, it is necessary to focus on its low-temperature performance and fatigue performance. In addition, to ensure water impermeability, the stress absorption layer should also have good waterproof performance. Therefore, after the test specimens prepared in the examples are formed, they are drilled and cut, and interlayer bonding performance tests, interlayer shear resistance tests, three-point bending tests, etc. of the composite layer specimens are carried out to evaluate the road performance of the above specimens. The test specimens are obtained by a cutting instrument and a road core drill.

[0053] 1. Interlayer pull-out test

[0054] 1) Test method:

[0055] To explore the influence of the interlayer bonding performance of different types of stress absorption layers, in addition to this example, pull-out test measurements were also carried out on specimens of two other types of stress absorption layers (specimen A (example): high-strength glass fiber rubber stress absorption layer, specimen B: SBS stress absorption layer, specimen C: modified emulsified asphalt tack coat). Specifically, an XH-15T roadbed and pavement bonding performance detector was used to conduct a pull-out test on the composite specimens. The interlayer pull-out strength of the three specimens was measured through the interlayer pull-out test, so as to reflect the bonding performance of different interlayers. Five specimens were selected for each stress absorption layer for the pull-out test, and the final pull-out strength was the average pull-out strength value of the five specimens.

[0056] 2) Analysis of test results:

[0057] In this test, a pull-out test was conducted on three specimens (15 cylindrical samples) (type A specimen: high-strength glass fiber rubber stress absorption layer, type B specimen: SBS stress absorption layer, type C specimen: modified emulsified asphalt tack coat). The bonding strength of each specimen was the test result of the pull-out strength corresponding to the five specimens, as shown in Table 2.

[0058] Table 2 Pull-out strength of five specimens

[0059]

[0060] As can be seen from the data in Table 2, the pull-out strength of the high-strength glass fiber rubber stress absorption layer exceeds 0.45 MPa, the pull-out strength of the SBS stress absorption layer is between 0.33 MPa and 0.40 MPa, while the pull-out strength of the modified emulsified asphalt tack coat is 0.18 MPa - 0.21 MPa. Through the calculation of the results of five tests, the pull-out strengths of the three types of specimens from high to low are Type A, Type B, and Type C. Among them, the pull-out strength of Type A specimens is the highest, reaching 0.51 MPa, and the lowest for Type C specimens, only 0.18 MPa. The pull-out strength of Type A is 1.6 times that of Type B and 2.19 times that of Type C respectively. The pull-out strength mainly depends on the bond strength between the aggregate and asphalt in the pavement layer. Type A specimens use rubber-modified asphalt, whose viscosity is significantly higher than that of traditional SBS-modified asphalt, while Type C specimens only sprinkle prime coat oil and do not use other asphalt, resulting in poor interlayer bond performance. After comprehensive comparison, the interlayer bond performance of Type A specimens is the best, and that of Type C specimens is the worst.

[0061] 2. Interlayer Shear Test

[0062] The current pavement design code in China is based on the elastic layered theory system, assuming that each structural layer is an ideal elastic body that is completely continuous, elastic, homogeneous, and isotropic. However, in actual engineering, due to significant differences in material properties between the semi-rigid base and the asphalt surface layer, the interlayer contact state between the two deviates significantly from the theoretical assumption. Especially during vehicle load braking, turning, or climbing, large shear stresses will be generated between the road layers. If the actual shear stress exceeds the allowable value between layers, interlayer peeling will occur, thus exacerbating the damage of the pavement structure.

[0063] To improve the consistency between the interlayer contact state and the code assumption, a highly viscous and low-modulus stress absorption layer can be added between the semi-rigid base and the asphalt lower surface layer to optimize the continuity and stress distribution between the two. Three types of materials, namely the high-strength glass fiber rubber asphalt stress absorption layer, SBS stress absorption layer, and non-sticking wheel modified emulsified asphalt tack coat prepared from the examples, are selected to analyze the shear effect between the semi-rigid base and the asphalt middle surface layer.

[0064] The test aims to measure the allowable interlayer shear stress (i.e., shear strength) under different working conditions to compare the shear performance differences of various stress absorption layers.

[0065] 1) Test Principle and Performance Evaluation Method

[0066] This test uses composite layer specimens for the test. The specimen specifications are cubes with dimensions of 5 cm * 5 cm * 5 cm. The test is carried out by using a SYE press in combination with fixtures with different shear angles. There are a total of five different shear angles for the shear fixtures (25°, 35°, 45°, 55°, 65°). For each type of specimen, 3 groups of parallel tests are carried out at each shear angle. The loading rate of the test is 10 mm / min. The test is carried out under an environment of 25°C. Before the test starts, the specimens need to be placed in an environment chamber at 25°C for more than 5 hours. The load at the time of specimen failure is such that the maximum shear strength corresponding to a single specimen is taken as the shear strength of the specimen. At this time, the normal stress and shear stress at the shear interface of the stress absorption layer are calculated according to the following formula:

[0067] σ = N·sinα / A (1)

[0068] τ = N·cosα / A (2)

[0069] In the formula: σ is the normal stress perpendicular to the bonding surface, MPa; τ is the shear stress perpendicular to the bonding surface, that is, the shear strength of the specimen, MPa; N is the shear failure load, KN; A is the bonding area, m2; α is the shear angle.

[0070] 2) Analysis of test results

[0071] In this test, the interlayer shear strength tests are carried out on three types of specimens (45 cubic specimens) at five different shear angles. The shear stress corresponding to the maximum failure load during the specimen shear process is taken as the shear strength of the current specimen. The failure load of each type of specimen is the average value of the failure loads corresponding to 3 specimens. Table 3 shows the shear strength and shear displacement information corresponding to the three types of specimens at five different angles.

[0072] Table 3 Shear strength of three types of specimens at different angles

[0073]

[0074] As can be seen from Table 3, with the increase of the shear angle, the failure loads of the three types of specimens gradually decrease. This is because the shear failure between road layers is caused by the shear stress being greater than the allowable shear stress between layers. As the shear angle increases, the effective proportion of the shear stress in the failure load gradually increases, resulting in a gradual decrease in the failure load. Among them, the failure load of the A-type specimen is the largest at each angle, and the failure load of the C-type specimen is the smallest. This may be related to the type of asphalt used in the stress absorption layer. By comparing the failure loads at 25°, the results show that the A-type specimen is 13.9% and 30.4% larger than the B-type and C-type specimens respectively. When the angle is increased to 65°, this result becomes 14.4% and 30.5%. In addition, as can be seen from Table 4-3, both the shear displacement and the shear stress decrease with the increase of the shear angle, indicating that the greater the road slope, the smaller the shear strength corresponding to the road layers, that is, the greater the road slope, the easier it is to occur shear failure. Through the comparison of the three stress absorption layers, it is found that the A-type specimen has the largest failure load, shear displacement, normal stress and shear strength at five shear angles, indicating that the shear resistance performance of the stress absorption layer between its layers is the most excellent. Therefore, this type of stress absorption layer is more suitable for application in sections with large shear stresses such as steep slopes, braking and turning.

[0075] According to the shear strength theory, the following formula is obtained:

[0076]

[0077] In the formula: τ f is the shear strength of the bonding surface, kPa; σ is the normal stress on the shear surface, kPa; is the internal friction angle of the bonding surface, °; c is the cohesion of the asphalt mixture, kPa.

[0078] According to the correlation between the shear stress and the normal stress of the A-type specimen at each shear angle, the shear strength curve of the A-type specimen can be obtained: τ f = 0.228σ + 0.58. The curve image is shown in Figure 1 . According to formula (2), the bonding force of the toughened stress absorption layer is 0.58 MPa, and the internal friction angle is 12.84°. It can be analyzed that this is due to the combined action of the rubber-modified asphalt and the glass fiber. Therefore, the shear resistance performance of this stress absorption layer is the best. It can be analyzed that the rubber-modified asphalt provides the interlayer bonding force, while the glass fiber and the crushed stone act together to provide the internal friction angle.

[0079] 3. Three-point bending test

[0080] The current pavement reflection cracks are mainly caused by the dry shrinkage and temperature shrinkage of semi-rigid base materials, indicating that the low-temperature performance of the materials is closely related to the crack resistance performance. The purpose of this test is to compare the crack resistance performance of three stress absorption layer specimens at low temperature, so the test temperature is set to low temperature. Since the stress absorption layer is located between the asphalt lower layer and the middle layer, and is far from the road surface, the temperature change is small. To be closer to the actual conditions, the test is carried out at three temperatures of -10°C, -5°C and 0°C to compare the low-temperature crack resistance performance of each stress absorption layer at different temperatures.

[0081] 1) Test principle and performance evaluation method

[0082] In this test, with the help of the UTM-25 electro-hydraulic servo loading test system, the test is carried out with reference to the T0715-2011 specification in the test procedures for asphalt and asphalt mixtures in highway engineering. The test temperatures are selected as -10°C, -5°C and 0°C. Before the test starts, in order to ensure that the inside of the test specimen reaches the planned test temperature, the specimen needs to be kept at the test temperature for more than 5 hours. The test is carried out using the composite beam specimens made in Section 3.1. The specimen specifications are 250mm * 30mm * 35mm. After the insulation time is reached, place the specimen on the upper part of the support. Note that the placement position of the specimen should be symmetric left and right and front and back, and ensure that the indenter is directly opposite the center of the specimen. At this time, the indenter contacts the upper part of the specimen but no load is applied. After that, close the protection door of the testing machine and then the test can be carried out. After the test starts, the indenter presses down according to the preset program. Finally, the composite small beam specimen is damaged by the upper indenter. The test failure load is recorded as N, and the flexural strength, maximum flexural strain and stiffness modulus corresponding to the specimen are calculated according to the following formulas:

[0083]

[0084] In the formula: R is the specimen failure load, MPa;

[0085] ε is the maximum flexural strain, με;

[0086] S is the bending stiffness modulus corresponding to the specimen, MPa;

[0087] b is the specimen cross-section width, mm;

[0088] h is the specimen cross-section height, mm;

[0089] d is the specimen cross-section diameter;

[0090] L is the specimen span, mm.

[0091] 2) Analysis of test results

[0092] This test conducted a composite beam low-temperature bending test on three types of specimens (27 small beam specimens) at three different temperatures. The maximum strain value during the bending process of the specimen was taken as the maximum flexural tensile strain of one specimen. The maximum flexural tensile strain of each type of specimen was the average of the maximum flexural tensile strains corresponding to 3 specimens. Table 4 shows the maximum flexural tensile strains and bending stiffness moduli corresponding to the three types of specimens at three different temperatures.

[0093] Table 4 Results of the low-temperature bending test of three types of specimens

[0094]

[0095] From the data in Table 4, it can be seen that the maximum flexural tensile strains of the three types of specimens all decrease with the decrease of temperature, and the maximum flexural tensile strain at each temperature is A > B > C. This indicates that among the three stress absorption layers, the low-temperature bending performance of the rubber stress absorption layer is better than the other two, and its low-temperature crack resistance is the best. Taking the maximum flexural tensile strain as an index, at -10°C, the low-temperature bending performance of Type A specimens is improved by 23.7% and 113.3% compared with Type B and Type C specimens, at -5°C by 27.1% and 71.3%, and at 0°C by 27.7% and 109.4%. As the test temperature decreases, the temperature stress inside the specimen gradually increases. When it accumulates to a certain extent, it may cause certain damage to the inside of the specimen, thereby reducing the flexural tensile strength of the specimen. This may be the reason why the flexural tensile strength corresponding to -5°C of the three types of specimens is the largest, while the flexural tensile strength corresponding to -10°C is lower than the former. Compared with the other two types of specimens, the low-temperature flexural tensile strength of Type A specimens is the largest, and its maximum flexural tensile strain can reach 3936 με (-10°C). This result far meets the requirement of 3000 με for modified asphalt mixtures in the current asphalt pavement construction specifications in China, indicating that the engineering application scope of the rubber stress absorption layer is wider.

[0096] Polyester fiber and basalt fiber were used to replace the high-strength glass fiber used in the present invention, and the prepared stress absorption layer was tested at the same dosage. The results are shown in Table 5.

[0097] Table 5 Comparison of various performances

[0098]

[0099] From the data in Table 5, it can be seen that at the same dosage, when used to prepare the stress absorption layer, the high-strength glass fiber is superior to polyester fiber and basalt fiber in terms of the three performances of drawing strength, flexural tensile strain, and shear strength. The performance of basalt fiber ranks second, and the performance of polyester fiber is relatively the worst.

[0100] An accelerated loading test (simulating 10 years of vehicle load) was conducted on Type A specimens, and the results are shown in Table 6 below.

[0101] Table 6 Results of the accelerated loading test

[0102] Test conditions Retention rate of interfacial bond strength Crack propagation rate (mm / 10,000 cycles) Initial state 100％ - After 10,000 cycles 95％ 0.12 After 50,000 cycles 88％ 0.25 After 100,000 cycles 82％ 0.38

[0103] As can be seen from the data in Table 6, the time obtained by the present invention can still maintain good interlayer bonding strength after multiple cycles.

[0104] The water stability tests were carried out on three types of specimens, and the results are shown in Table 7.

[0105] Table 7 Water Stability Test Results

[0106]

[0107] As can be seen from the data in Table 7, Specimen A is less affected by water, and the decline in the pull-out strength after immersion is relatively small, so its water stability is better; the decline in the pull-out strength of Specimen B after immersion is greater than that of Specimen A, and its water stability is worse than that of Specimen A; Specimen C has the lowest strength retention rate among the three specimens, and the pull-out strength drops significantly after immersion, so its water stability is the worst.

[0108] The water permeability of Specimen A is extremely weak, which can better prevent water intrusion, is beneficial to maintaining the internal structure stability, and enhances the water stability. The water permeability of Specimen B is stronger than that of Specimen A, and water is more likely to invade, which has a certain impact on its internal structure and performance. Specimen C has the largest water permeability coefficient and the strongest water permeability among the three specimens, with a large amount of water intrusion, which will seriously affect the performance of the specimen and lead to poor water stability.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-strength glass fiber-reinforced rubber asphalt stress absorption layer, characterized in that, It includes the following components: rubber asphalt, high-strength glass fiber, basalt gravel, and 70# base asphalt with an asphalt-aggregate ratio of 0.5%; Among them, the rubber asphalt is obtained by compound modification of 70# base asphalt and waste rubber powder in a ratio of 1:0.18 - 0.22; The interfacial bonding strength of the stress absorption layer is ≥0.5 MPa, and the maximum flexural tensile strain at -10°C is ≥3900 με.

2. The stress absorption layer of rubber asphalt reinforced by high-strength glass fiber according to claim 1, characterized in that: The length of the high-strength glass fiber is 3 - 12 cm, and the dosage is 120 - 180 g / m 2 .

3. The stress absorption layer of rubber asphalt reinforced by high-strength glass fiber according to claim 1, characterized in that: The particle size of the basalt gravel is 9.5 - 13.2 mm, and the spreading amount is 14 kg / m 2 .

4. The preparation method of a high-strength glass fiber-reinforced rubber asphalt stress absorption layer according to any one of claims 1-3, characterized in that, It includes the following steps: Step 1. Material pretreatment 1) High-speed shear mixing and stirring of waste rubber powder and 70# base asphalt to form compound modified rubber asphalt; 2) Conducting air flow screening treatment on high-strength glass fiber to obtain high-strength glass fiber with a length of 3 - 12 cm; Step 2. Treatment of semi-rigid material base Roughening the semi-rigid base and spraying coal tar seal coat; Step 3. Preparation of stress absorption layer 1) Premixing and spreading of gravel: Mix basalt gravel and 70# base asphalt with an asphalt-aggregate ratio of 0.5% evenly, and the spreading thickness is 2 - 3 cm; 2) Spraying of rubber asphalt: Heat the compound modified rubber asphalt and spray it on the surface of the gravel to form an asphalt bonding layer; 3) Sprinkling of glass fiber: Uniformly disperse high-strength glass fiber above the asphalt bonding layer to complete the laying of the stress absorption layer; 4) Compaction and shaping: Lay an asphalt surface layer above the stress absorption layer, and use a shaping machine to compact and shape the stress absorption layer.

5. The preparation method of a high-strength glass fiber-reinforced rubber asphalt stress absorption layer according to claim 4, characterized in that: In Step 1, the mixing temperature of waste rubber powder and 70# base asphalt is 107 - 190°C; the stirring time is 30 min.

6. The preparation method of a high-strength glass fiber-reinforced rubber asphalt stress absorption layer according to claim 4, characterized in that: In Step 3, the heating temperature of the compound modified rubber asphalt is 195 - 205°C.

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