High-temperature pavement crack sealant and its preparation method

Abstract

The present invention provides a high-temperature pavement joint sealant and a preparation method thereof, which relates to the technical field of pavement maintenance. The components include a premix, a polymer modifier, a tackifier, a stabilizer, and a filler; the filler contains a finely separated recycled material. The high-temperature pavement joint sealant of the present invention has the characteristics of high temperature and high resilience by adding rubber-modified asphalt, improves the low-temperature performance by adding a polymer modifier, ensures the viscosity and durability by adding a tackifier, and ensures the stability and anti-aging property by adding a stabilizer. Each material plays a synergistic role to balance the comprehensive performance of the joint sealant, making the joint sealant have good high-temperature stability performance, while balancing the low-temperature performance and elastic recovery performance, being more environmentally adaptable, and having a lower high-temperature viscosity. The performance of the joint sealant is balanced, the construction is convenient, and the cost is low. The present invention realizes the simple and efficient recycling of the finely separated recycled material by adding the finely separated recycled material, and solves the problem of low recycling rate of the finely separated recycled material.

Description

Technical Field

[0001] The present invention relates to the technical field of pavement maintenance, and particularly relates to a high-temperature pavement crack sealant and a preparation method thereof. Background Art

[0002] Common crack sealants are divided into cold-pouring type, hot-pouring type and chemical material type. Among them, the hot-pouring asphalt crack sealant has the advantages of good adhesion to the old pavement, low cost, and mature application. It is a commonly used highway maintenance material for repairing asphalt pavement cracks and filling cement pavement. However, there are still common problems such as uneven performance and poor application effect. To meet the actual service environment requirements of long-term vehicle load, water, and high temperature, the crack sealant needs to have good water sealing performance, strong adhesion to the old pavement, good anti-aging performance, etc. At the same time, to meet the convenience of crack sealing construction, the crack sealant needs to have a lower viscosity at high temperature. The technical defects of existing heating-type crack sealants are mainly reflected in technical problems such as cumbersome processing of polymer-modified asphalt, high construction viscosity, and poor environmental adaptability.

[0003] CN201210262849.7 proposes a high-temperature asphalt pavement crack sealant and a preparation method thereof. The crack sealant is composed of a compatibilizer, a modifier, a stabilizer and matrix asphalt. The compatibilizer is the second-line extract oil or the third-line extract oil with a high aromatic content or a mixture thereof. For the third-line extract oil, its preparation involves many processes, and the oil output needs to reach a certain standard, increasing the preparation cost. And during the preparation process, the compatibilizer needs to be preheated to 40-60°C and then blended with the matrix asphalt, and the preparation steps are relatively cumbersome. Although the crack sealant has certain high and low temperature properties and deformation recovery ability, its molecular polarity is low, and the long-term bonding repair effect on pavement cracks is not ideal.

[0004] CN202010487751.6 prepares a crack sealant by using matrix asphalt, silica resin, tackifying resin and additives, etc. The flow value of the crack sealant obtained by this preparation method is greater than 0 at 60°C. The crack sealant may be extruded from the crack with the increase of the environmental temperature and taken away by the tires of passing vehicles, thus affecting the stability of the treated crack, and its applicable high-temperature environment is relatively limited.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] One of the purposes of the present invention is to provide a high-temperature pavement crack sealant to solve at least one of the technical problems existing in the prior art. The components of the high-temperature pavement crack sealant provided by the present invention include a premix, a polymer modifier, a tackifier, a stabilizer and a filler. Through the specific and synergistic effects of each component material, the crack sealant has good high-temperature stability and better comprehensive performance, making the crack sealant more environmentally adaptable.

[0007] The second object of the present invention is to provide a preparation method of a high-temperature pavement crack sealant. The preparation method of the high-temperature pavement crack sealant provided by the present invention first prepares a rubber-modified asphalt premix, and then adds other components for blending. The pre-preparation process of the premix reduces the preparation time of the later crack sealant, and at the same time enables the rubber powder and the matrix asphalt to be fully fused with each other, improving the uniformity and quality stability of the crack sealant.

[0008] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0009] In the first aspect, the present invention provides a high-temperature pavement crack sealant, which includes the following components: a premix, a polymer modifier, a tackifier, a stabilizer, and a filler;

[0010] Among them, the premix includes rubber powder and matrix asphalt.

[0011] Further, the high-temperature pavement crack sealant includes the following components by mass percentage:

[0012] 65%-75% premix, 2%-4% polymer modifier, 0.5%-1.5% tackifier, 0.1%-0.5% stabilizer, and 10%-32% filler;

[0013] Among them, the premix includes the following components by mass percentage: 15%-25% rubber powder and 75%-85% matrix asphalt.

[0014] Further, the matrix asphalt includes 70# heavy traffic matrix asphalt;

[0015] The particle size of the rubber powder is 60-100 mesh, the ash content of the rubber powder ≤ 18%, and the acetone extract content of the rubber powder ≤ 20%.

[0016] Further, the filler includes at least one of a finely separated recycled material and stone powder;

[0017] Preferably, the stone powder includes at least one of mineral powder and talc powder;

[0018] Preferably, the particle size of the finely separated recycled material ≤ 3 mm, the moisture content of the finely separated recycled material ≤ 0.5%, the old asphalt content of the finely separated recycled material is 6%-8%, and the penetration of the old asphalt ≥ 20 (0.1 mm);

[0019] Preferably, the particle size of the stone powder ≤ 0.15 mm.

[0020] Further, the polymer modifier includes at least one of linear T6302H type, T161 type, and T171 type styrene-butadiene-styrene block copolymers.

[0021] Further, the tackifier includes at least one of C9 resin, C5 resin, and EVA.

[0022] Further, the stabilizer includes sulfur.

[0023] In a second aspect, the present invention provides a method for preparing the high-temperature pavement crack sealant as described above, comprising the following steps:

[0024] Mix the rubber powder and the base asphalt according to the formula amount to obtain a premix.

[0025] Mix the premix, the polymer modifier, the tackifier, the stabilizer, and the filler according to the formula amount to obtain the high-temperature pavement crack sealant.

[0026] Further, the process of mixing the rubber powder and the base asphalt includes: heating the base asphalt to 160°C - 170°C, adding the rubber powder, stirring for 20 - 30 min to obtain mixture A, controlling the temperature of mixture A to 170 - 180°C, performing shearing for 20 - 40 min at a shearing rate of 4000 - 6000 r / min, and then stirring for 10 - 12 h at a stirring rate of 1500 - 2000 r / min to obtain the premix.

[0027] Further, the pretreatment process of the finely separated recycled material includes: performing dry fine separation treatment on the asphalt mixture recycled material, and screening to obtain the finely separated recycled material.

[0028] The process of mixing the premix, the polymer modifier, the tackifier, the stabilizer, and the filler includes: controlling the temperature of the premix to 175°C - 185°C, adding the polymer modifier, the tackifier, and the finely separated recycled material, stirring for 30 - 60 min at a stirring rate of 600 - 1000 r / min, then performing shearing for 20 - 40 min at a shearing rate of 4500 - 5000 r / min, then stirring for 2 - 4 h to obtain mixture B, maintaining the temperature of mixture B at 175°C - 185°C, adding the stabilizer, and stirring for 1 - 2 h at a stirring rate of 600 - 1000 r / min to obtain mixture C. When the filler further includes stone powder, maintaining the temperature of mixture C at 175°C - 185°C, adding other fillers, and then stirring for 1 - 2 h at a stirring rate of 600 - 1000 r / min.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The high-temperature pavement joint sealant provided by the present invention has components with high-temperature and high-rebound characteristics by adding rubber-modified asphalt, improves low-temperature performance by adding polymer modifiers, ensures tackiness and durability by adding tackifiers, and ensures stability and anti-aging properties by adding stabilizers. Various materials play specific and synergistic roles to balance the comprehensive performance of the joint sealant, making the joint sealant more environmentally adaptable, having good high-temperature stability performance, while balancing low-temperature performance and elastic recovery performance, and having a relatively low high-temperature viscosity. The performance of the joint sealant is balanced, the construction is convenient, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a flowchart of the method for preparing the pavement joint sealant provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meanings and scopes of the terms should be clear. However, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or extrinsic definition. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "comprising" and other forms is non-restrictive.

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] The present invention provides a high-temperature pavement joint sealant in a first aspect, comprising the following components: premix, polymer modifier, tackifier, stabilizer, and filler;

[0036] Wherein, the premix includes rubber powder and matrix asphalt.

[0037] The crack sealant for road surface in the present invention is a high-temperature type crack sealant for road surface. The components of the high-temperature type crack sealant for road surface have the characteristics of high temperature and high resilience by adding rubber-modified asphalt, improve the low-temperature performance by adding polymer modifiers, ensure the viscosity and durability by adding tackifiers, and ensure the stability and anti-aging property by adding stabilizers. Various materials play specific and synergistic roles to balance the comprehensive performance of the crack sealant, making the crack sealant more adaptable to the environment, having good high-temperature stability (the softening point can reach > 100 °C), while balancing the low-temperature performance (passing at 0 °C, 25%, 3 cycles), elastic recovery performance (the elastic recovery can reach > 40%), and having a relatively low high-temperature viscosity (the Brookfield viscosity at 180 °C can reach < 10 Pa·s). The crack sealant has balanced performance, convenient construction, and low cost.

[0038] In some preferred embodiments, the high-temperature type crack sealant for road surface comprises the following components by mass percentage:

[0039] 65%-75% premix, 2%-4% polymer modifier, 0.5%-1.5% tackifier, 0.1%-0.5% stabilizer, and 10%-32% filler;

[0040] Based on the total mass of the high-temperature type crack sealant for road surface being 100%, the addition amount of the premix is 65%-75%, for example, it can be 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, etc.;

[0041] Based on the total mass of the high-temperature type crack sealant for road surface being 100%, the addition amount of the polymer modifier is 2%-4%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, etc.;

[0042] Based on the total mass of the high-temperature type crack sealant for road surface being 100%, the addition amount of the tackifier is 0.5%-1.5%, for example, it can be 0.5%, 1%, 1.5%, etc.;

[0043] Based on the total mass of the high-temperature type crack sealant for road surface being 100%, the addition amount of the stabilizer is 0.1%-0.5%, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.;

[0044] Based on the total mass of the high-temperature type crack sealant for road surface being 100%, the addition amount of the filler is 10%-32%, for example, it can be 10%, 15%, 20%, 25%, 30%, 32%, etc.;

[0045] Among them, the premix comprises the following components by mass percentage: 15%-25% rubber powder and 75%-85% base asphalt.

[0046] Based on the total mass of the premix being 100%, the addition amount of the rubber powder is 15% - 25%, for example, it can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.;

[0047] Based on the total mass of the premix being 100%, the addition amount of the matrix asphalt is 75% - 85%, for example, it can be 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, etc.

[0048] In some preferred embodiments, the matrix asphalt includes 70# heavy traffic matrix asphalt;

[0049] In the present invention, the matrix asphalt is one of the main components of the crack sealant. As the main binder, it provides good water sealing performance and bonding performance, and together with the polymer modifier and rubber powder, it improves the viscoelasticity and anti-aging ability of the crack sealant.

[0050] Preferably, the particle size of the rubber powder is 60 - 100 mesh, the ash content value of the rubber powder ≤ 18%, and the acetone extract content of the rubber powder ≤ 20%.

[0051] In the present invention, the requirement for the ash content value is ≤ 18% because the actual effective rubber components in the rubber powder with a high ash content value are reduced, which will weaken the modification effect; the requirement for the acetone extract content is ≤ 20%. A lower acetone extract content means a lower content of soluble impurities in the rubber powder, ensuring the quality of the crack sealant. The rubber powder mainly comes from waste tires of automobiles. Adding rubber powder to the crack sealant is a composite modification effect: after the rubber powder undergoes swelling and degradation in the matrix asphalt, it can improve the high-temperature stability performance and low-temperature deformation characteristics of the crack sealant; the carbon-carbon bonds and carbon-sulfur bonds in the rubber will break and recombine at the high temperature during the preparation of the crack sealant to form a more stable molecular structure. This process helps to improve the durability and anti-aging performance of the modified crack sealant; the carbon black particles in the rubber powder are evenly distributed in the crack sealant, acting as fillers, increasing the density and viscosity of the crack sealant, reducing its fluidity, and enhancing the high-temperature stability; in addition, the rubber powder plays a physical support role in the crack sealant, forming a structure similar to a skeleton, enhancing the stability of the internal structure of the crack sealant; the presence of the rubber powder can fill the micro-pores in the crack sealant, making the structure of the crack sealant more compact, improving the water damage resistance and anti-aging performance of the crack sealant. The rubber powder and the SBS modifier act synergistically to enhance the crack resistance and tensile strength of the crack sealant.

[0052] In some preferred embodiments, the filler includes at least one of fine separation recycled material and stone powder;

[0053] The pavement crack sealant in the present invention is a high-temperature pavement crack sealant containing finely separated recycled materials. RAP is a solid waste generated during the maintenance and repair of highway asphalt pavements. RAP consists of two parts: old aggregates and old asphalt, which are bonded together. Recycling it through plant-mixed hot recycling and then reusing it in asphalt pavements is a commonly used technical approach. The fine separation technology is a pretreatment method for RAP, which can strip the old asphalt from the old aggregates on RAP, and the old asphalt on the coarse-grade RAP is enriched on the fine-grade RAP, so as to solve the problems of particle bonding and difficult control of aggregate gradation. The present invention makes full use of the old asphalt and old aggregates in the finely separated recycled materials, supplements the asphalt and stone powder required for the crack sealant, reduces the usage of new materials, lowers the material cost of the crack sealant, and at the same time gives play to the advantages of the high softening point index of the old asphalt and the viscosity reduction and elasticity increase of the ground old aggregates as fillers. The present invention uses the old asphalt and old aggregates in the finely separated recycled materials to provide the necessary raw materials for the crack sealant, and combines with the improvement of the crack sealant preparation method. Without increasing the processing cost, it solves the problems of difficult regeneration and low regeneration utilization rate of the finely separated fine-grade recycled materials caused by the secondary aging of the regeneration drum heating, low admixture amount of the recycled mixture and unstable performance in plant-mixed hot recycling due to the finely separated fine-grade recycled materials. The invention realizes the simple and efficient regeneration utilization of the finely separated recycled materials and solves the problem of low regeneration utilization rate of the finely separated recycled materials.

[0054] Preferably, the particle size of the finely separated recycled material is ≤ 3 mm, the moisture content of the finely separated recycled material is ≤ 0.5%, the old asphalt content of the finely separated recycled material is 6% - 8%, and the penetration (100 g, 25 °C, 5 s) of the old asphalt is ≥ 20 (0.1 mm);

[0055] In the present invention, the finely separated recycled material is treated by a dry fine separation technology, and its maximum particle size does not exceed 3 mm. On the one hand, because the content of old asphalt in this part of the recycled material is the highest and the utilization value is higher, and also to ensure that the smaller finely separated recycled material in the preparation method can enter the colloid mill, so as to ensure the shearing efficiency and shearing effect. At the same time, the smaller particle size also provides a larger specific surface area, so as to ensure that the old asphalt can be in full contact with the premix and promote miscibility; the content of old asphalt is required to be 6% - 8%. On the one hand, to ensure there is sufficient old asphalt and thus reflect the utilization value, while limiting the too high content of old asphalt is to avoid its adverse impact on the matrix asphalt dosage or the performance of the crack sealant; the penetration is used to characterize the aging degree of the old asphalt, and it is required that the penetration of the old asphalt (100 g, 25 °C, 5 s) ≥ 20 (0.1 mm), which can ensure that the old asphalt in the finely separated recycled material has a certain flexibility and plasticity, and the matrix asphalt can fully regenerate it; the moisture content of the finely separated recycled material ≤ 0.5%, which is to ensure the heating efficiency of the finely separated recycled material and the accuracy of material metering. The finely separated recycled material plays the role of replacing stone powder and a part of the matrix asphalt. Under the preparation method of the present invention, under the action of high temperature, shearing and the penetration of asphalt micelles, the old aggregates in the finely separated recycled material are sheared from the maximum particle size of 3 mm to less than 0.075 mm, and the old asphalt in the finely separated recycled material is miscible with the premix. Among them, the large asphalt micelles break, exposing many active sites, and these active sites combine with small molecules in the asphalt to form a semi-polymerization effect, which can form a new asphalt colloid, thus realizing the regeneration of the old asphalt in the finely separated recycled material.

[0056] Preferably, the stone powder includes at least one of mineral powder and talc powder;

[0057] Preferably, the particle size of the stone powder ≤ 0.15 mm.

[0058] In the present invention, the stone powder is the stone powder processed from natural crushed stones, the passing rate of the 0.075 mm sieve hole ≥ 90%, and the passing rate of the 0.15 mm sieve hole is 100%. More preferably, it is the mineral powder or talc powder processed from limestone. Due to the characteristics of uniform particle size and strong dispersibility of the stone powder, it can enhance the adhesion between asphaltene and SBS and resin, make the crack sealant easier to adhere to the road cracks, and enhance the bonding force. In addition, the stone powder can improve the high-temperature fluidity of the crack sealant, making it easier to construct and coat, and facilitating the control of the construction fluidity and coverage area of the crack sealant. Adding stone powder can reduce the temperature sensitivity of the crack sealant, because the stone powder can adsorb on the surface of asphalt molecules to form a firm asphalt film, thereby improving the viscosity and durability of the crack sealant and ensuring good construction performance.

[0059] In some preferred embodiments, the polymer modifier includes at least one of linear T6302H type, T161 type and T171 type styrene-butadiene-styrene (SBS) block copolymers.

[0060] In the present invention, the SBS modifier can improve the high and low temperature performance, anti-aging ability and durability of the crack filling adhesive. The three-dimensional network structure formed by SBS at high temperature adsorbs the oil in the asphalt, expands the swelling volume, and the polymer changes from the dispersed phase to the continuous phase. Under the action of external stirring and shearing, it is mainly physically modified, improving the high and low temperature performance of the crack filling adhesive. The SBS modifier acts together with the rubber powder and resin, enabling the crack filling adhesive to maintain stable performance under both high and low temperature conditions and balancing the high and low temperature performance.

[0061] In some preferred embodiments, the tackifier includes at least one of C9 resin, C5 resin and EVA.

[0062] In the present invention, the resin is further preferably C9 resin or EVA, with a molecular weight less than 2000. The resin is a by-product of petroleum cracking and is a thermoplastic resin obtained by copolymerization with aldehydes, aromatics, etc. under the action of a catalyst. The main function of the resin is to increase the viscosity and toughness of the crack filling adhesive, thereby improving the performance and service life of the crack filling adhesive. The mechanism is that the resin chemically reacts with the oil in the asphalt to form a complex with viscosity and ductility; after the resin is added, the network structure of SBS is enhanced, and the light components formed by the swelling and cracking of the rubber powder are restricted, forming more asphalt micelles, which interact with the micelles formed by SBS, thereby improving the adhesion and durability of the crack filling adhesive.

[0063] In some preferred embodiments, the stabilizer includes sulfur.

[0064] In the present invention, the main function of the stabilizer is to improve the stability of the crack filling adhesive, prevent the crack filling adhesive from delaminating and separating, and improve the anti-aging performance of the crack filling adhesive. The main mechanism is that sulfur interacts with the polar and non-polar groups in the matrix asphalt to form a stable three-dimensional network structure, inhibiting phase separation. In addition, it initiates the cross-linking reaction of the SBS modifier, enhancing the stability of the crack filling adhesive.

[0065] The second aspect of the present invention provides a preparation method for a high-temperature type pavement crack filling adhesive, comprising the following steps:

[0066] Mix the rubber powder and the matrix asphalt according to the formula amount to obtain a premix;

[0067] Mix the premix, polymer modifier, tackifier, stabilizer and filler according to the formula amount to obtain the high-temperature type pavement crack filling adhesive.

[0068] In some preferred embodiments, the process of mixing the rubber powder and the base asphalt includes: heating the base asphalt to 160°C - 170°C, adding the rubber powder, and stirring for 20 - 30 minutes, such as 20 minutes, 25 minutes, 30 minutes, etc., to obtain mixture A. Controlling the temperature of mixture A to 170 - 180°C, such as 170°C, 175°C, 180°C, etc., and performing shearing for 20 - 40 minutes, such as 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc., with a shearing rate of 4000 - 6000 r / min, such as 4000 r / min, 5000 r / min, 6000 r / min, etc. Then stirring for 10 - 12 hours, such as 10 hours, 11 hours, 12 hours, etc., with a stirring rate of 1500 - 2000 r / min, such as 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min, 1900 r / min, 2000 r / min, etc., to obtain the premix.

[0069] In some preferred embodiments, the pretreatment process of the finely separated recycled material includes: performing dry fine separation treatment on the recycled asphalt mixture (RAP) and screening to obtain the finely separated recycled material;

[0070] The process of mixing the premix, polymer modifier, tackifier, stabilizer and filler includes: controlling the temperature of the premix to 175°C - 185°C, for example, it can be 175°C, 180°C, 185°C, etc., adding the polymer modifier, tackifier, and finely separated recycled material, stirring for 30 - 60 min, for example, it can be 30 min, 40 min, 50 min, 60 min, etc., with a stirring rate of 600 - 1000 r / min, for example, it can be 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, etc., then performing shearing for 20 - 40 min, for example, it can be 20 min, 30 min, 40 min, etc., with a shearing rate of 4500 - 5000 r / min, for example, it can be 4500 r / min, 4600 r / min, 4700 r / min, 4800 r / min, 4900 r / min, 5000 r / min, etc., then stirring for 2 - 4 h, for example, it can be 2 h, 3 h, 4 h, etc., to obtain mixture B, maintaining the temperature of mixture B at 175°C - 185°C, for example, it can be 175°C, 180°C, 185°C, etc., adding the stabilizer, and stirring for 1 - 2 h, for example, it can be 1 h, 1.5 h, 2 h, etc., with a stirring rate of 600 - 1000 r / min, for example, it can be 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, etc., to obtain mixture C. When the filler also includes stone powder, maintaining the temperature of mixture C at 175°C - 185°C, for example, it can be 175°C, 180°C, 185°C, etc., adding other fillers, and then stirring for 1 - 2 h, for example, it can be 1 h, 1.5 h, 2 h, etc., with a stirring rate of 600 - 1000 r / min, for example, it can be 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, etc.

[0071] The preparation method of the pavement crack sealant provided by the present invention provides raw materials with lower preparation cost for the crack sealant. In addition, through the optimization of raw materials and formulation, the comprehensive road performance of traditional crack sealants is improved, thereby ensuring the application effect of asphalt pavement crack treatment or cement pavement filling.

[0072] Further, preferably, as Figure 1 shown, the preparation method of the pavement crack sealant specifically includes the following steps:

[0073] (1) Weigh each raw material by mass percentage: 15% - 25% of rubber powder, and the rest is matrix asphalt;

[0074] (2) Heat the matrix asphalt to 160°C - 170°C, and at the same time add the rubber powder to the matrix asphalt heated to a flowing state, and pre-stir for 20 - 30 min to obtain mixture A;

[0075] (3) Control the temperature of mixture A to 170 - 180 °C, carry out high-speed shearing for 20 - 40 min at a shearing rate of 4000 - 6000 r / min, and then stir for 10 - 12 h under temperature control at a stirring rate of 1500 - 2000 r / min to obtain a premix;

[0076] (4) Pretreat the finely separated recycled material. The recycled asphalt mixture (RAP) is subjected to dry fine separation treatment, and the finely separated recycled material with a maximum particle size not exceeding 3 mm is obtained by screening, dried at 60 °C until the moisture content ≤ 0.5%, and kept warm at 60 °C.

[0077] (5) Weigh the raw materials by mass percentage: 65% - 75% premix, 2% - 4% polymer modifier, 0.5% - 1.5% resin, 0.1% - 0.5% stabilizer, and the total amount of stone powder and finely separated recycled material is 10% - 32%.

[0078] (6) Control the temperature of the premix to 175 °C - 185 °C, and at the same time add the weighed polymer modifier, resin, and finely separated recycled material, stir for 30 - 60 min at a stirring rate of 600 - 1000 r / min, then carry out high-speed shearing for 20 - 40 min at a shearing rate of 4500 - 5000 r / min, and continue to stir for 2 - 4 h to obtain mixture B;

[0079] (7) Keep mixture B at 175 °C - 185 °C, add the stabilizer, and continue to stir for 1 - 2 h at a stirring rate of 600 - 1000 r / min to obtain mixture C. If no stone powder is added, then mixture C is a high-temperature type pavement joint sealant containing finely separated recycled material;

[0080] (8) If stone powder needs to be added, then keep mixture C at 175 °C - 185 °C, add the stone powder, and continue to stir for 1 - 2 h at a stirring rate of 600 - 1000 r / min. After stopping stirring, a high-temperature type pavement joint sealant containing finely separated recycled material is obtained.

[0081] In view of the problems of complex conventional crack sealant processes and unbalanced performance, and considering the in-depth regeneration of old asphalt in the finely separated recycled materials and the sufficient shearing of old aggregates, the present invention proposes a preparation process for crack sealant. First, a rubber-modified asphalt premix is prepared, then a polymer modifier, a tackifier, and the finely separated recycled materials are shear-blended, and finally a stabilizer is added. This process has significant advantages: First, various materials play specific and synergistic roles (the high-temperature and high-rebound characteristics of rubber asphalt, the polymer modifier improves low-temperature performance, the tackifier ensures viscosity and durability, the stabilizer ensures stability and anti-aging properties, and there are interactions among components such as asphalt, SBS, rubber powder, and resin), balancing the comprehensive performance of the crack sealant and making the crack sealant more environmentally adaptable; Second, the prior preparation of the rubber-modified asphalt premix reduces the later preparation time of the crack sealant. This prefabrication process enables the rubber powder and the matrix asphalt to fully blend with each other, improving the uniformity and quality stability of the crack sealant; Third, the addition of the finely separated recycled materials does not increase the additional preparation time and can be blended with the polymer modifier and the tackifier. This not only simplifies the preparation process but also balances the high-temperature stability, elastic recovery, and viscosity level of the crack sealant.

[0082] The present invention will be further described below through examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0083] Example 1

[0084] This example provides a high-temperature pavement crack sealant, which includes the following components by mass percentage:

[0085] 70.8% premix, 2.5% SBS modifier of type T6302H, 0.7% C9 resin, 0.1% sulfur, and 25.9% talc powder;

[0086] Among them, the premix includes the following components by mass percentage: 20% rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0087] Among them, the particle size of the rubber powder is 60 mesh, the ash content is ≤18%, and the acetone extract is ≤20%; the talc powder meets the requirements that the passing rate through a 0.075mm sieve hole is 92% and the passing rate through a 0.15mm sieve hole is 100%.

[0088] Example 2

[0089] This example provides a high-temperature pavement crack sealant, which is different from Example 1 in that the content of stone powder is changed. The talc powder is 28.6%, the premix is 68.1%, and the rest is the same as in Example 1.

[0090] Example 3

[0091] This embodiment provides a high-temperature pavement joint sealant. The difference from Embodiment 1 is that the content of stone powder is changed. Talc powder is 31.0%, premix is 65.7%, and the rest is the same as in Embodiment 1.

[0092] Embodiment 4

[0093] This embodiment provides a high-temperature pavement joint sealant. The difference from Embodiment 2 is that the content of SBS modifier is changed. T6302H type SBS modifier is 2.1%, premix is 68.5%, and the rest is the same as in Embodiment 2.

[0094] Embodiment 5

[0095] This embodiment provides a high-temperature pavement joint sealant. The difference from Embodiment 2 is that the filler includes stone powder and finely separated recycled material. Talc powder is 14.3%, finely separated recycled material is 14.3%, and the rest is the same as in Embodiment 2.

[0096] Embodiment 6

[0097] This embodiment provides a high-temperature pavement joint sealant. The difference from Embodiment 2 is that the filler includes finely separated recycled material. Finely separated recycled material is 28.6%, and the rest is the same as in Embodiment 2.

[0098] Embodiment 7

[0099] This embodiment provides a high-temperature pavement joint sealant. The difference from Embodiment 2 is that C9 resin is replaced by EVA, and the rest is the same as in Embodiment 2.

[0100] Embodiment 8

[0101] This embodiment provides a high-temperature pavement joint sealant, which includes the following components by mass percentage:

[0102] 63.4% premix, 4% T6302H type SBS modifier, 0.5% C9 resin, 0.1% sulfur, 16% talc powder and 16% finely separated recycled material;

[0103] Among them, the premix includes the following components by mass percentage: 15% rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0104] Among them, the particle size of the rubber powder is 60 mesh, the ash content ≤ 18%, and the acetone extract ≤ 20%.

[0105] Embodiment 9

[0106] This embodiment provides a high-temperature pavement joint sealant, which includes the following components by mass percentage:

[0107] 75.5% premix, 2% T6302H type SBS modifier, 1.5% C9 resin, 0.5% sulfur, 10.25% talcum powder and 10.25% finely separated recycled material;

[0108] Among them, the premix includes the following components by mass percentage: 25% rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0109] Among them, the particle size of the rubber powder is 60 mesh, the ash content ≤ 18%, and the acetone extract ≤ 20%.

[0110] Examples 10 - 13

[0111] Examples 10 - 13 provide a preparation method of a high - temperature type pavement crack sealant. In Examples 10 - 13, the raw materials are weighed according to the component dosage in Examples 1 - 4 respectively, and specifically include the following steps:

[0112] (1) Weigh each raw material by mass percentage according to the formula dosage in Examples 1 - 4 respectively: including rubber powder and 70# heavy traffic matrix asphalt;

[0113] (2) Heat the matrix asphalt to 170 °C, and at the same time add the rubber powder to the matrix asphalt heated to a flowing state to obtain mixture A;

[0114] (3) Control the temperature to 175 °C, carry out high - speed shearing for 20 min, the shearing rate is 4500 r / min, and then stir for 12 h under the temperature - controlled state, the stirring rate is 1500 r / min, to obtain the premix;

[0115] (4) Weigh the raw materials by mass percentage according to the formula dosage in Examples 1 - 4 respectively: including premix, T6302H type SBS modifier, C9 resin, sulfur and talcum powder.

[0116] (5) Control the temperature to 180 °C, add SBS and resin at the same time, stir for 30 min, the stirring rate is 800 r / min, then carry out high - speed shearing for 20 min, the shearing rate is 4500 r / min, and continue to stir for 2 h to obtain mixture B;

[0117] (6) Control the temperature to 180 °C, add sulfur, and continue to stir for 1 h, the stirring rate is 800 r / min;

[0118] (7) Control the temperature to 180 °C, add talcum powder, and continue to stir for 1 h, the stirring rate is 800 r / min;

[0119] (8) After stopping stirring, obtain a high - temperature type pavement crack sealant.

[0120] Example 14

[0121] This embodiment provides a preparation method of a high-temperature pavement crack sealant. Weigh the raw materials according to the component dosage in Example 5. The specific steps are as follows:

[0122] (1) Weigh each raw material according to the formula dosage in Example 5 by mass percentage: 20% rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0123] (2) Heat the matrix asphalt to 170°C, and at the same time add the rubber powder to the matrix asphalt heated to a flowing state to obtain mixture A;

[0124] (3) Control the temperature to 175°C, carry out high-speed shearing for 20 min, the shearing rate is 4500 r / min, and then stir for 12 h under the temperature control state, the stirring rate is 1500 r / min, to obtain a premix;

[0125] (4) Prepare 0 - 2.36 mm oil-rich old materials from RAP through dry fine separation, and dry at 60°C until the moisture content < 0.5%;

[0126] (5) Weigh the raw materials by mass percentage: 68.1% premix, 2.5% T6302H type SBS modifier, 0.7% C9 resin, 0.1% sulfur, 14.3% talcum powder, 14.3% fine separation recycled material.

[0127] (6) Control the temperature to 180°C, and at the same time add SBS, resin, and fine separation recycled material, stir for 30 min, the stirring rate is 800 r / min, then carry out high-speed shearing for 20 min, the shearing rate is 4500 r / min, and continue to stir for 2 h to obtain mixture B;

[0128] (7) Add sulfur at a temperature of 180°C and continue to stir for 1 h, the stirring rate is 800 r / min;

[0129] (8) Add talcum powder at a temperature of 180°C and continue to stir for 1 h, the stirring rate is 800 r / min. After stopping stirring, a high-temperature pavement crack sealant containing fine separation recycled material is obtained.

[0130] Example 15

[0131] This embodiment provides a preparation method of a high-temperature pavement crack sealant. The difference from Example 14 is that the addition order of SBS, resin, and fine separation recycled material is adjusted;

[0132] In step (6), the temperature is controlled to 180°C, SBS and resin are added, and stirred for 30 min at a stirring rate of 800 r / min. Subsequently, high-speed shearing is carried out for 10 min at a shearing rate of 4500 r / min. Then, the finely separated recycled material is added and stirred for 30 min at a stirring rate of 800 r / min, followed by high-speed shearing for 10 min at a shearing rate of 4500 r / min, and then stirred continuously for 2 h to obtain mixture B;

[0133] The remaining steps are the same as those in Example 14.

[0134] Example 16

[0135] This example provides a preparation method of a high-temperature pavement crack sealant. The difference from Example 14 is that the addition order of SBS, resin, and the finely separated recycled material is adjusted;

[0136] In step (6), the temperature is controlled to 180°C, the finely separated recycled material is added, and stirred for 30 min at a stirring rate of 800 r / min. Subsequently, high-speed shearing is carried out for 10 min at a shearing rate of 4500 r / min. Then, SBS and resin are added and stirred for 30 min at a stirring rate of 800 r / min, followed by high-speed shearing for 10 min at a shearing rate of 4500 r / min, and then stirred continuously for 2 h to obtain mixture B;

[0137] The remaining steps are the same as those in Example 14.

[0138] Example 17

[0139] This example provides a preparation method of a high-temperature pavement crack sealant. Weigh the raw materials according to the component dosage in Example 6, which specifically includes the following steps:

[0140] (1) Weigh each raw material according to the formula dosage in Example 6 by mass percentage: 20% of rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0141] (2) Heat the matrix asphalt to 170°C, and at the same time add the rubber powder to the matrix asphalt heated to a flowing state to obtain mixture A;

[0142] (3) Control the temperature to 175°C, carry out high-speed shearing for 20 min at a shearing rate of 4500 r / min, and then stir for 12 h at a stirring rate of 1500 r / min under the temperature control state to obtain a premix;

[0143] (4) Prepare 0 - 2.36 mm oil-rich old material from RAP by dry fine separation, and dry it at 60°C until the moisture content < 0.5%;

[0144] (5) Weigh the raw materials by mass percentage: 68.1% premix, 2.5% SBS modifier of type T6302H, 0.7% C9 resin, 0.1% sulfur, and 28.6% finely separated recycled material;

[0145] (6) Control the temperature to 180 °C, and at the same time add SBS, resin, and finely separated recycled material, stir for 30 min, the stirring rate is 800 r / min, then carry out high-speed shearing for 20 min, the shearing rate is 4500 r / min, and continue to stir for 2 h to obtain mixture B;

[0146] (7) Control the temperature to 180 °C, add sulfur, and continue to stir for 1 h, the stirring rate is 800 r / min;

[0147] (8) After stopping stirring, a high-temperature pavement joint sealant containing finely separated recycled material is obtained.

[0148] Example 18

[0149] This example provides a preparation method of a high-temperature pavement joint sealant. Weigh the raw materials according to the component dosage in Example 7, and the preparation method is the same as that in Example 11.

[0150] Example 19

[0151] This example provides a preparation method of a high-temperature pavement joint sealant. Weigh the raw materials according to the component dosage in Example 8, and specifically include the following steps:

[0152] (1) According to the formula dosage in Example 8, weigh each raw material by mass percentage: 15% rubber powder, and the rest is 70# heavy traffic matrix asphalt;

[0153] (2) Heat the matrix asphalt to 160 °C, and at the same time add rubber powder to the matrix asphalt heated to a flowing state to obtain mixture A;

[0154] (3) Control the temperature to 180 °C, carry out high-speed shearing for 40 min, the shearing rate is 4000 r / min, and then stir for 10 h under the controlled temperature state, the stirring rate is 2000 r / min, to obtain a premix;

[0155] (4) RAP is prepared into 0 - 2.36 mm oil-rich old material through dry fine separation, and dried at 60 °C until the moisture content < 0.5%;

[0156] (5) Weigh the raw materials by mass percentage: 65% premix, 4% SBS modifier of type T6302H, 1% C9 resin, 0.1% sulfur, 14.95% talc powder, and 14.95% finely separated recycled material;

[0157] (6) Control the temperature to 175°C, and at the same time add SBS, resin, and finely separated recycled material, stir for 60 min at a stirring rate of 600 r / min, then perform high-speed shearing for 40 min at a shearing rate of 5000 r / min, and continue stirring for 4 h to obtain mixture B;

[0158] (7) Control the temperature to 175°C, add sulfur, and continue stirring for 2 h at a stirring rate of 600 r / min;

[0159] (8) Control the temperature to 175°C, add talcum powder, and continue stirring for 2 h at a stirring rate of 600 r / min. After stopping stirring, a high-temperature type pavement crack sealant containing finely separated recycled material is obtained.

[0160] Example 20

[0161] This example provides a preparation method for a high-temperature type pavement crack sealant. Weigh the raw materials according to the component dosage in Example 9, which specifically includes the following steps:

[0162] (1) Weigh each raw material according to the formula dosage in Example 9 by mass percentage: 25% rubber powder, and the rest is 70# heavy traffic base asphalt;

[0163] (2) Heat the base asphalt to 165°C, and at the same time add rubber powder to the base asphalt heated to a flowing state to obtain mixture A;

[0164] (3) Control the temperature to 175°C, perform high-speed shearing for 30 min at a shearing rate of 6000 r / min, and then stir for 11 h at a stirring rate of 1750 r / min under temperature control to obtain a premix;

[0165] (4) Prepare 0 - 2.36 mm oil-rich old material from RAP through dry fine separation, and dry it at 60°C until the moisture content < 0.5%;

[0166] (5) Weigh the raw materials by mass percentage: 75% premix, 2% T6302H type SBS modifier, 2% C9 resin, 0.5% sulfur, 10.25% talcum powder, and 10.25% finely separated recycled material;

[0167] (6) Control the temperature to 185°C, and at the same time add SBS, resin, and finely separated recycled material, stir for 45 min at a stirring rate of 1000 r / min, then perform high-speed shearing for 30 min at a shearing rate of 4750 r / min, and continue stirring for 3 h to obtain mixture B;

[0168] (7) Control the temperature to 185°C, add sulfur, and continue stirring for 1.5 h at a stirring rate of 1000 r / min;

[0169] (8) When the temperature is controlled to 185 °C, add talcum powder and continue stirring for 1.5 h at a stirring rate of 1000 r / min. After stopping stirring, a high-temperature type pavement crack sealant containing finely separated recycled materials is obtained.

[0170] Comparative Example 1

[0171] This comparative example provides a preparation method of a high-temperature type pavement crack sealant. The difference from Example 11 is that no rubber asphalt premixed material is prepared, and the specific steps are as follows:

[0172] (1) Weigh each raw material by mass percentage: 20% of rubber powder, and the rest is 70# heavy traffic base asphalt;

[0173] (2) Weigh the raw materials by mass percentage: the total content of rubber powder and base asphalt is 68.1%, T6302H type SBS modifier is 2.5%, C9 resin is 0.7%, sulfur is 0.1%, and talcum powder is 28.6%;

[0174] (3) Control the temperature to 180 °C, add rubber powder, SBS, and resin to the base asphalt at the same time, stir for 30 min at a stirring rate of 800 r / min, then perform high-speed shearing for 20 min at a shearing rate of 4500 r / min, and continue stirring for 2 h;

[0175] (4) Under the temperature control state, add sulfur and continue stirring for 1 h at a stirring rate of 800 r / min;

[0176] (5) Under the temperature control state, add talcum powder and continue stirring for 1 h at a stirring rate of 800 r / min;

[0177] (6) After stopping stirring, a high-temperature type pavement crack sealant is obtained.

[0178] Comparative Example 2

[0179] This comparative example provides a preparation method of a high-temperature type pavement crack sealant. The difference from Example 17 is that the raw material components of Comparative Example 2 do not contain SBS modifier, that is, (5) weigh the raw materials by mass percentage: 70.6% of premixed material, 0.7% of C9 resin, 0.1% of sulfur, and 28.6% of finely separated recycled materials, and the preparation method is the same as that of Example 17.

[0180] Test samples: The high-temperature type pavement crack sealants prepared in Examples 10 - 20 and the high-temperature type pavement crack sealants prepared in Comparative Examples 1 - 2 are used as test samples.

[0181] Test Method

[0182] The test method is carried out according to Table 1 below.

[0183] Table 1

[0184] Test Items Test Methods Softening Point (°C) JTG E20 T 0606 Penetration (25°C, 0.1 mm) JT / T 740-2015 Elastic Recovery Rate (%) JT / T 740-2015 Low Temperature Tensile JT / T 740-2015 Brookfield Viscosity (Pa·s) JTG E20 T 0625

[0185] Test Example 1

[0186] In the above embodiments, the same fine separation and recycled material is used, with an old asphalt content of 7.8%, an old asphalt penetration (100 g, 25 °C, 5 s) of 29 (0.1 mm), and the particle size distribution of the old aggregates shown in Table 2.

[0187] Table 2

[0188]

[0189] Test samples: The sealants provided in Example 11 and Comparative Example 1. The test results are shown in Table 3.

[0190] Table 3

[0191]

[0192] As can be seen from Table 3, the indexes such as softening point, penetration, and elastic recovery rate of Comparative Example 1 are inferior to those of Example 11. It can be seen that adopting the method of pre-preparing the rubber asphalt premixed material proposed in the embodiments of the present invention, that is, using shearing and stirring with a long time and reasonable process, helps the rubber powder to fully swell, degrade, and disperse evenly in the asphalt phase, thereby ensuring that the sealant has good high-temperature stability and ductility.

[0193] Test Example 2

[0194] Test samples: The sealants provided in Example 11 and Example 18.

[0195] Table 4

[0196]

[0197] As can be seen from the data in Table 4, when the resin uses C9 resin or EVA, the performance of the sealant can meet the requirements. Comparing the two, the overall performance indexes of the sealant using EVA are better, and the Brookfield viscosity is lower.

[0198] Test Example 3

[0199] Test samples: The sealants provided in Example 10, Example 11, and Example 12.

[0200] Table 5

[0201]

[0202] As can be seen from the data in Table 5, an appropriate amount of stone powder can reduce the internal friction of the cementitious material, improve the fluidity of the crack-sealing adhesive, make it easier for the crack-sealing adhesive to fill into the road surface cracks, and improve the construction efficiency. However, too much stone powder will also reduce the strength of the crack-sealing adhesive and increase the porosity. When the addition amounts of the SBS modifier and the resin are kept consistent, as the stone powder addition amount increases, the softening point of the crack-sealing adhesive increases. When the stone powder addition amount exceeds 28.6%, the softening point decreases slightly. When the stone powder addition amount is 28.6%, the elastic recovery rate of the crack-sealing adhesive reaches the maximum.

[0203] Test Example 4

[0204] Test samples: The crack-sealing adhesives provided in Example 11 and Example 13.

[0205] Table 6

[0206]

[0207] As can be seen from the data in Table 6, when the stone powder addition amount and the resin remain unchanged, increasing the addition amount of the SBS modifier is beneficial to the increase of the softening point. However, too high an addition amount of the SBS modifier will increase the cost of the crack-sealing adhesive. When the SBS addition amount is 2.1% - 2.5%, it already meets the requirements of the JT / T 740-2015 technical standard.

[0208] Test Example 5

[0209] Test samples: The crack-sealing adhesives provided in Example 14, Example 15, and Example 16.

[0210] Table 7

[0211]

[0212] As can be seen from Table 7, different processes have an impact on the performance indicators of the crack-sealing adhesive, and the addition order of the finely separated recycled material has a great influence on the performance of the crack-sealing adhesive. When adding SBS, resin, and finely separated recycled material simultaneously (Example 14), its performance indicators are the best. In addition, by comparing Example 15 and Example 16, it can be found that for the crack-sealing adhesive prepared by preferentially adding the finely separated recycled material, its softening point, penetration, and elastic recovery all increase, and the viscosity decreases, which is beneficial to construction. This is caused by the different lengths of the addition time of the finely separated recycled material. The longer the stirring time of the finely separated recycled material, the better the miscibility of the old asphalt and the matrix asphalt, and the more sufficient the shearing of the old mineral aggregate, and the better the performance of the crack-sealing adhesive.

[0213] Test Example 6

[0214] Test samples: The crack-sealing adhesives provided in Comparative Example 1 - 2, Example 11, Example 14, Example 17, and Example 19 - 20. The test results are shown in the following table.

[0215] Table 8

[0216]

[0217] As can be seen from the test data in the above table, Examples 11, 14, 17, 19 - 20 can all meet the requirements of "Pavement Heating Type Sealant" (JT / T 740 - 2015). The high - temperature pavement crack - filling glue containing fine separated recycled materials provided by the present invention has good high - temperature performance, deformation characteristics, and bonding ability, and all indicators are superior to those of the crack - filling glue prepared only with stone powder in Comparative Example 1. At the same time, through the analysis of Examples 11, 14, and 17, it can be found that all indicators of Examples 14 and 17 are superior to those of Example 11. After adding the fine separated recycled materials, the softening point increases by more than 4 °C, improving the high - temperature performance of the crack - filling glue, the elastic recovery rate increases by more than 14%, improving the deformation characteristics of the crack - filling glue, and at the same time the viscosity decreases, thus improving the workability during construction. Through the analysis of Examples 11, 14, and 17, it is found that as the content of the fine separated recycled materials increases, the softening point and elastic recovery rate of the crack - filling glue both increase, and the viscosity decreases, which is beneficial to on - site construction. Example 17 has better comprehensive performance, a high dosage of the fine separated recycled materials, and at the same time treats two major solid wastes, waste tires and fine separated recycled materials, is environmentally friendly, and has considerable economic benefits. Analyzing the reasons, after the fine separated recycled materials are dissolved in the rubber asphalt, under the action of high temperature and shear, the large asphalt micelles will break, exposing many active sites, and these active sites combine with small molecules in the asphalt to form a semi - polymerization effect, which can form a new asphalt colloid, and then form a spatial network structure, thus achieving the effect of improving the performance of the crack - filling glue.

[0218] In addition, in Examples 11, 14, and 17, the content of old asphalt in the fine separated recycled materials is 7.8%. Using the aged asphalt in the fine separated recycled materials to replace part of the matrix asphalt can reduce the amount of matrix asphalt and lower the cost.

[0219] It can be seen from the data in the table that compared with Comparative Example 17, Comparative Example 2 lacks the synergistic effect of the SBS modifier and other components, and the performance of each index of the crack - filling glue decreases, and the comprehensive performance deteriorates.

[0220] Finally, it should be noted that: the above - mentioned embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent substitution on some or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-temperature pavement crack sealant, characterized in that, The high-temperature pavement joint sealant comprises the following components by mass percentage: 65%-75% premix, 2%-4% polymer modifier, 0.5%-1.5% tackifier, 0.1%-0.5% stabilizer and 10%-32% filler; Among them, the premix comprises the following components by mass percentage: 15%-25% rubber powder and 75%-85% base asphalt; The filler includes finely separated recycled material and stone powder; the tackifier includes at least one of C9 resin, C5 resin and EVA; the stabilizer includes sulfur.

2. The high-temperature type pavement crack sealant according to claim 1, wherein The base asphalt includes 70# heavy traffic base asphalt; The particle size of the rubber powder is 60-100 mesh, the ash content of the rubber powder is ≤18%, and the acetone extract content of the rubber powder is ≤20%.

3. The high-temperature type pavement crack sealant according to claim 1, characterized in that, The stone powder includes at least one of mineral powder and talc powder.

4. The high-temperature type pavement joint sealant according to claim 1, wherein, The particle size of the finely separated recycled material is ≤3 mm, the moisture content of the finely separated recycled material is ≤0.5%, the old asphalt content of the finely separated recycled material is 6%-8%, and the penetration of the old asphalt is ≥20 (in 0.1 mm).

5. The high-temperature type pavement crack sealant according to claim 1, wherein, The particle size of the stone powder is ≤0.15 mm.

6. The high-temperature pavement joint sealant according to claim 1, wherein The polymer modifier includes at least one of linear styrene-butadiene-styrene block copolymers of type T6302H, T161 and T171.

7. The preparation method of the high-temperature pavement crack sealant according to any one of claims 1-6, characterized in that, It includes the following steps: Mix the rubber powder and the base asphalt according to the formula amount to obtain a premix; Mix the premix, polymer modifier, tackifier, stabilizer and filler according to the formula amount to obtain the high-temperature pavement joint sealant.

8. The preparation method of the high-temperature type pavement crack sealant according to claim 7, characterized in that The process of mixing the rubber powder and the base asphalt includes: heating the base asphalt to 160℃-170℃, adding the rubber powder, stirring for 20-30 min to obtain mixture A, controlling the temperature of mixture A to 170-180℃, performing shearing for 20-40 min at a shearing rate of 4000-6000 r / min, and then stirring for 10-12 h at a stirring rate of 1500-2000 r / min to obtain a premix.

9. The preparation method of the high-temperature pavement joint sealant according to claim 7, characterized in that, The pretreatment process of the finely separated recycled material includes: performing dry fine separation treatment on the asphalt mixture recycled material and screening to obtain the finely separated recycled material; The process of mixing the premix, polymer modifier, tackifier, stabilizer and filler includes: controlling the temperature of the premix to 175℃-185℃, adding the polymer modifier, tackifier and finely separated recycled material, stirring for 30-60 min at a stirring rate of 600-1000 r / min, then performing shearing for 20-40 min at a shearing rate of 4500-5000 r / min, and then stirring for 2-4 h to obtain mixture B, keeping the temperature of mixture B at 175℃-185℃, adding the stabilizer, stirring for 1-2 h at a stirring rate of 600-1000 r / min to obtain mixture C. When the filler also includes stone powder, keeping the temperature of mixture C at 175℃-185℃, adding other fillers, and then stirring for 1-2 h at a stirring rate of 600-1000 r / min.

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