CMCA ultra-thin wearing layer pavement and construction method thereof

Abstract

The application discloses a CMCA ultra-thin wearing layer pavement and a construction method thereof. The CMCA ultra-thin wearing layer pavement comprises, from bottom to top, a crack grouting treatment layer, a high-strength bonding layer and a CMCA mixture layer. After disease treatment of the original pavement, the high-strength bonding layer material is uniformly sprayed, and the spraying amount is 0.3-0.6 kg / m2; after the high-strength bonding layer is surface-dried, the 1.5-2.5 cm-thick CMCA mixture layer is uniformly spread; and after the CMCA mixture is surface-dried, the traffic is opened. Compared with the existing cold-mixed and cold-paved ultra-thin overlay maintenance technology, the technology greatly improves the skid resistance and service life of the wearing layer, and the bonding strength is also significantly improved, effectively solving the problems of the current cold-mixed and cold-paved ultra-thin overlay, such as large stone falling, peeling, skid resistance attenuation and crack reflection, and simultaneously having the advantages of long service life, high bonding strength, good water damage resistance and the like of the high-viscosity and high-elasticity ultra-thin hot overlay.

Description

Technical Field

[0001] This invention belongs to the field of asphalt pavement pre-maintenance, specifically relating to a CMCA ultra-thin wearing course pavement and its construction method. Background Technology

[0002] Preventive maintenance of highway pavements is an effective protective measure taken when early, minor defects appear on the road surface. It aims to reduce the degree of damage, extend the service life of the road, and improve various pavement performance aspects. It primarily involves early pre-maintenance to prevent damage to the internal structure of the pavement, thereby increasing its service life and reducing the frequency of medium and major repairs. Preventive maintenance is a defensive measure and cannot address problems caused by structural damage to the pavement.

[0003] my country's highway construction has progressed for decades, and the continuous increase in the total number of vehicles has led to a sharp increase in traffic volume. Many roads have gradually developed minor defects, and some have already entered the medium to major repair stage. If these early damages are not addressed promptly, the road surface will suffer greater damage or even structural failure during use, severely shortening its service life and affecting road driving quality. This also leads to a sharp decrease in the economic benefits per unit of construction cost. Therefore, taking effective measures to extend the service life of roads, save maintenance funds, and protect the environment is of great practical significance. As the concept and related technologies of preventive maintenance are gradually accepted by transportation and management units, some new maintenance materials and technologies have been applied in engineering projects and have achieved certain practical results. High-performance, long-life, highly functional, and cost-effective asphalt pavement pre-maintenance technology is currently the main demand point for preventive maintenance.

[0004] Common preventative maintenance techniques include: ultra-thin wearing layers, super-adhesive wearing layers, micro-surfacing, synchronous chip seal, sand-containing fog seal, surface milling and repaving, and in-situ thermal recycling. With the growing popularity of "green" and environmentally friendly concepts, high-energy-consuming and high-polluting materials and processes are becoming increasingly unfriendly. Cold-mix cold-lay preventative maintenance techniques, such as super-adhesive wearing layers, micro-surfacing, synchronous chip seal, and sand-containing fog seal, have gained favor among many maintenance and construction management companies due to their ease of construction, low cost, energy efficiency, and environmental friendliness. However, due to limitations in material properties, practical applications often encounter problems such as severe degradation of skid resistance, aggregate detachment, oil seepage, peeling and flaking due to low bond strength, short lifespan, and high noise levels.

[0005] In cold-mix cold-lay maintenance technology, the super-adhesive wearing course is currently a relatively balanced maintenance technique. The main binder used is styrene-butadiene latex-modified emulsified asphalt, which has many advantages such as simple construction, energy saving, reduced pollution, and economy. However, based on recent maintenance engineering practices, it has become increasingly clear that using emulsified asphalt or styrene-butadiene latex-modified emulsified asphalt as a binder generally suffers from disadvantages such as low bond strength, high temperature sensitivity, low softening point, and poor aging resistance. This makes it unsuitable for high traffic volumes and heavy traffic conditions, thus hindering the promotion and application of emulsified asphalt in asphalt pavement maintenance and repair. Furthermore, the characteristics of existing materials dictate that current cold-mix cold-lay thin-layer treatment technologies can only employ dense mixing, resulting in a smaller amount of coarse aggregate. Moreover, due to the low softening point of the binder, large aggregates tend to detach significantly at higher temperatures, leaving only fine aggregate and binder material. This leads to a severe reduction in pavement skid resistance and a tendency for bleeding. Summary of the Invention

[0006] To effectively overcome the problems of severe skid resistance degradation, aggregate detachment, and peeling in current cold-mixed and cold-laid ultra-thin overlays, and to address the shortcomings of high-viscosity, high-elasticity, ultra-thin hot overlays such as high energy consumption and complex construction, this invention develops a CMCA (Coldmixed Coarse Aggregate) ultra-thin wearing course pavement and its construction method. This ultra-thin wearing course fully leverages the workability and environmental friendliness of cold-mixed and cold-laid thin overlays while also exhibiting the advantages of high-viscosity, high-elasticity, ultra-thin hot overlays, such as long service life, good adhesion, and excellent skid resistance.

[0007] The CMCA ultra-thin wear-resistant course pavement construction method includes the following steps:

[0008] ① Assess the pavement quality, and take core samples from the surface layer and base layer where the defects are located to analyze the root cause and extent of the defects; for cracks in the surface layer and base layer, perform crack filling treatment by filling the cracks in the base layer and surface layer with polymer grout material A until the grout material completely penetrates and fills the cracks; for loose base layer defects, use organic-inorganic composite grout material B to form a unified whole; for rutting defects in the surface layer exceeding 5mm, milling and leveling are required.

[0009] ② After the original road surface has been treated for defects, spray a high-strength bonding layer material evenly at a rate of 0.3-0.6 kg / m². 2 ;

[0010] ③ After the high-strength adhesive layer material is surface dry, evenly spread a 1.5-2.5cm thick CMCA mixture layer;

[0011] ④ Once the CMCA mixture has dried to the surface, traffic can be opened, thus completing the CMCA ultra-thin wearing course pavement construction.

[0012] The polymer grouting material A for the base layer and surface layer is a two-component epoxy resin modified polyurethane material; wherein component 1, by weight, comprises 10-40 parts castor oil, 20-30 parts polyether polyol 1, 5-10 parts polyether polyol 2, 5-10 parts polyester polyol, 5-10 parts prepolymer epoxy resin, 0.1-0.3 parts catalyst, 10-40 parts 400-800 mesh CaCl2 and 10-30 parts ethyl acetate, which are mixed and stirred evenly to achieve a viscosity of 1000-3000 mPa·s at 25°C; component 2, by weight, comprises 50-90 parts crude MDI, 10-30 parts filler and 10-40 parts ethyl acetate, to achieve a viscosity of 1000-3000 mPa·s at 25°C.

[0013] The specific operation of the crack grouting treatment is as follows: Drill grouting holes and venting holes at the cracks. The diameter of the holes is 2-5cm, the depth is the thickness of the asphalt mixture layer, and the distance between the two holes is not less than 50cm. Seal the surface of the remaining cracks with glass glue. After the drilling is completed and the glass glue has cured, mix component 1 and component 2 at a mass ratio of 1:1-1.2 using a coaxial mixing and grouting device and inject them evenly into the grouting holes until the polymer grouting material A for the base and surface layers is discharged from the venting holes. Stop grouting when the grouting pressure is 0.5-2MPa.

[0014] The organic-inorganic composite grouting material B is composed of 20 parts by weight of 50-60% solid content polyacrylate emulsion, 70 parts of silicate cement (425 type cement, average particle size <5μm), 1-2 parts of polystyrene cyclopentadiene water-reducing agent, 8-12 parts of calcium aluminate type expansion agent, 3-4 parts of sulfate type early strength agent and 40 parts of water.

[0015] The high-strength adhesive layer material is composed of 10-30 parts by weight of polyacrylate emulsion with a solid content of 50-60% and 70-90 parts by weight of emulsified SBS modified bitumen with a solid content of 60% (SBS content 5%).

[0016] The polyether polyol 1 is a propylene glycol condensation polymer with a molecular weight of 3000, a functionality of 3, a hydroxyl value of 56 mg KOH / g, and a viscosity of 800–1000 mPa·s at 25°C. The associated polyether polyol 2 is polymerized from trimethylolpropane and propylene oxide, with a molecular weight of 450, a functionality of 3, a hydroxyl value of 380 mg KOH / g, and a viscosity of 500–800 mPa·s at 25°C. The polyester polyol is polymerized from phthalic anhydride and glycerol, with a molecular weight of 530, a functionality of 3, and a hydroxyl value of 315 mg KOH / g. The KOH / g and viscosity at 25℃ are 1500-2500 mPa·s; the prepolymer epoxy resin is prepared by reacting 70 parts by weight of E51, 30 parts by weight of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, and 13-15 parts by weight of ethylenediamine at room temperature; the catalyst is composed of 10 parts by weight of stannous octoate, 10 parts by weight of triethylenediamine, and 10 parts by weight of glycerol.

[0017] The method for preparing CMCA mixture includes: mixing 100 parts by weight of discontinuously graded aggregate evenly; adding 3-5 parts by weight of water and mixing the aggregate for 15-30 seconds to evenly wet the aggregate; spraying 15-20 parts by weight of modified emulsified asphalt evenly onto the surface of the aggregate and mixing for 30-90 seconds to ensure that the modified emulsified asphalt is evenly coated with the aggregate and that the modified emulsified asphalt is mixed with the mineral powder and fine aggregate until a viscous state is achieved.

[0018] The modified emulsified asphalt is made by mixing 5-15 parts by weight of waterborne epoxy resin, 5-15 parts by weight of waterborne epoxy amine curing agent, and 70-90 parts by weight of emulsified SBS modified asphalt (5% SBS content) with a solid content of 60%.

[0019] The discontinuously graded stone material is composed of 1-2 parts by weight of 6mm chopped glass fiber, 5-8 parts by weight of mineral powder, 15-25 parts by weight of 1-3mm basalt stone, 50-60 parts by weight of 5-10mm basalt stone, and 10-30 parts by weight of 10-15mm basalt stone.

[0020] The advantages of this invention are:

[0021] 1. Compared with the existing cold-mixed and cold-laid ultra-thin overlay curing technology, this technology greatly improves the anti-slip performance and service life of the wear layer, while also significantly improving the bonding strength. It effectively solves the problems of large stone detachment, peeling, reduced anti-slip performance, and crack reflection in current cold-mixed and cold-laid ultra-thin overlays.

[0022] 2. This technology has the advantages of long service life, high bonding strength and good water resistance of high viscosity and high elasticity ultra-thin heat cover surface. Compared with high viscosity and high elasticity ultra-thin heat cover surface, it has the advantages of energy saving and environmental protection, outstanding construction and ease of construction, fast construction speed and low cost.

[0023] 3. Compared with conventional ultra-thin overlay maintenance technology, this technology has thoroughly treated base layer cracks, base layer loosening, and surface layer cracks, thus making the original pavement and subgrade a whole. The thin maintenance surface layer laid on the treated old pavement can greatly give full play to the advantages of the surface layer such as high bonding strength, good wear resistance, and long service life, and significantly improve the performance of the original pavement. Detailed Implementation

[0024] To better understand this invention, the following embodiments further illustrate its content; however, the invention is not limited to these embodiments. If the experiments and construction based on this invention do not involve creative improvements or labor by the construction personnel, then these embodiments also fall within the scope of protection of this invention.

[0025] All values ​​in this embodiment are test values ​​under laboratory conditions. In order to better compare the differences with the existing cold-mixed and cold-laid thin-layer overlay technology, the indicators tested in this experiment are all based on the existing conventional super-adhesive wear layer 1h wet wheel wear, 6d wet wheel wear and 100,000 cycles accelerated loading test to test the water damage resistance and wear resistance of different wear layer pavements.

[0026] To simulate real-world conditions, the crack grouting performance was tested by cutting the rutted slab in the middle, bonding it with a special polymer grouting material A for the base and surface layers, and then laying a CMCA ultra-thin wear layer on the surface. The difference in height after accelerated loading was then measured. Similar tests were conducted on conventional ultra-adhesive wear layers and high-viscosity, high-elasticity ultra-thin heat-sealed surfaces. 1-hour and 6-day wet wheel abrasion tests were performed using conventional wet wheel abrasion testing methods.

[0027] Example 1:

[0028] The CMCA ultra-thin wear layer consists of, from bottom to top: crack grouting treatment layer, high-strength bonding layer, and CMCA mixture layer.

[0029] 1) The construction method of CMCA ultra-thin wearing course pavement includes the following steps:

[0030] ① Assess the pavement quality, and take core samples from the surface layer and base layer where the defects are located to analyze the root cause and extent of the defects. For defects such as cracks in the surface layer and base layer, perform crack filling treatment, including treatment of cracks in the base layer and surface layer. The main treatment method is grouting technology, which involves filling the cracks with a special polymer grouting material A for the base layer and surface layer until the grouting material completely penetrates and fills the cracks. For defects such as loose base layer, grouting treatment is also required using organic-inorganic composite grouting material B to form a unified whole. For surface layer rutting defects exceeding 5mm, milling and leveling are required.

[0031] ② After the original road surface has been treated for defects, spray a high-strength bonding layer material evenly at a rate of 0.3-0.6 kg / m². 2 ;

[0032] ③ After the high-strength adhesive layer is surface dry, spread a 2cm thick layer of CMCA mixture evenly.

[0033] ④ After the CMCA mixture has dried to the touch, traffic can be opened, thus completing the CMCA ultra-thin wear-resistant layer pavement construction.

[0034] 2) Base and surface layer special polymer grouting material A is a two-component epoxy resin modified polyurethane material. Its preparation and construction methods include:

[0035] ①The base and surface layer special polymer grouting material A component 1 includes 40 parts castor oil, 20 parts polyether polyol 1, 10 parts polyether polyol 2, 5 parts polyester polyol, 10 parts prepolymer epoxy resin, 0.1 parts catalyst, 10 parts 400-800 mesh CaCl2 and 10 parts ethyl acetate. The mixture is stirred evenly and its viscosity at 25℃ is tested to be 2500 mPa·s.

[0036] ② The polymer grouting material for base and surface layers, component A2, consists of 50 parts crude MDI, 30 parts filler and 20 parts ethyl acetate by weight. Its viscosity at 25℃ is 1800 mPa·s.

[0037] ③ Simulate drilling, seal the area around the rut plate crack with sealant, leaving grouting port and vent. Mix component 1 and component 2 at a mass ratio of 1:1.1 using a coaxial mixing and grouting device, and inject them into the grouting hole until the base and surface special polymer grouting material A is discharged from the vent. Stop grouting at a grouting pressure of 0.8MPa.

[0038] 3) Indoor tests do not involve loose substrate, so this step is not performed.

[0039] 4) The high-strength adhesive layer material is made by mixing 20 parts of 60% solid content polyacrylate emulsion with 80 parts of 60% solid content emulsified SBS modified bitumen (5% SBS content).

[0040] 5) Modified emulsified asphalt is made by mixing 15 parts of waterborne epoxy resin, 15 parts of waterborne epoxy amine curing agent and 70 parts of emulsified SBS modified asphalt with a solid content of 60% (SBS content 5%).

[0041] 6) Discontinuous graded stone material is composed of 2 parts 6mm short-cut glass fiber, 5 parts mineral powder, 20 parts 1-3mm basalt stone material, 60 parts 5-10mm basalt stone material and 20 parts 10-15mm basalt stone material.

[0042] The polyether polyol 1 is a propylene glycol condensate with a molecular weight of 3000, a functionality of 3, a hydroxyl value of 56 mg KOH / g, and a viscosity of 800–1000 mPa·s at 25°C; the polyether polyol 2 is a polymer of trimethylolpropane and propylene oxide with a molecular weight of 450, a functionality of 3, a hydroxyl value of 380 mg KOH / g, and a viscosity of 500–800 mPa·s at 25°C; the polyester polyol is a polymer of phthalic anhydride and glycerol with a molecular weight of 530, a functionality of 3, and a hydroxyl value of 315 mg KOH / g. The KOH / g and viscosity at 25℃ are 1500~2500mPa·s; the prepolymer epoxy resin is prepared by reacting 70 parts of E51, 30 parts of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 15 parts of ethylenediamine at room temperature; the catalyst is a mixture of 10 parts of stannous octoate, 10 parts of triethylenediamine and 10 parts of glycerol.

[0043] The method for preparing the CMCA mixture includes:

[0044] ① Mix 100 parts by weight of discontinuously graded aggregate evenly;

[0045] ② Add 5 parts water and mix the stone for 30 seconds to evenly moisten the stone;

[0046] ③ Spray 20 parts of modified emulsified asphalt evenly onto the surface of the stone, mix for 90 seconds, so that the modified emulsified asphalt is evenly coated with the stone, and the modified emulsified asphalt is mixed with the mineral powder and fine aggregate until a viscous state is achieved.

[0047] ④ Use a paver to evenly spread the mixed CMCA mixture onto the road surface, and adjust the paving thickness to meet the design requirements.

[0048] The corresponding wet wheel wear parts are also prepared according to the above method.

[0049] Example 2:

[0050] The experimental procedure is the same as in Example 1, with the following differences:

[0051] 2) Base and surface layer special polymer grouting material A is a two-component epoxy resin modified polyurethane material. Its preparation and construction methods include:

[0052] ①The base and surface layer special polymer grouting material A component 1 includes 10 parts castor oil, 30 parts polyether polyol 1, 5 parts polyether polyol 2, 10 parts polyester polyol, 5 parts prepolymer epoxy resin, 0.3 parts catalyst, 25 parts 400-800 mesh CaCl2 and 15 parts ethyl acetate. The mixture is stirred evenly and its viscosity at 25℃ is tested to be 2100 mPa·s.

[0053] ②The polymer grouting material for base and surface layers, component A2, consists of 80 parts crude MDI, 10 parts filler and 10 parts ethyl acetate by weight. Its viscosity at 25℃ is 2400 mPa·s.

[0054] ③ Simulate drilling, seal the area around the rut plate crack with sealant, leaving grouting port and vent. Mix component 1 and component 2 at a mass ratio of 1:1.2 using a coaxial mixing and grouting device, and inject them into the grouting hole until the base and surface special polymer grouting material A is discharged from the vent. Stop grouting at a grouting pressure of 2MPa.

[0055] 3) Indoor tests do not involve loose substrate, so this step is not performed.

[0056] 4) The high-strength adhesive layer material is made by mixing 30 parts of 50% solid content polyacrylate emulsion with 70 parts of 60% solid content emulsified SBS modified bitumen (5% SBS content).

[0057] 5) Modified emulsified asphalt is made by mixing 5 parts of waterborne epoxy resin, 5 parts of waterborne epoxy amine curing agent and 90 parts of emulsified SBS modified asphalt with a solid content of 60% (SBS content 5%).

[0058] 6) Discontinuous graded stone material is composed of 1 part 6mm short-cut glass fiber, 8 parts mineral powder, 15 parts 1-3mm basalt stone material, 50 parts 5-10mm basalt stone material and 26 parts 10-15mm basalt stone material.

[0059] The corresponding wet wheel wear parts are also prepared according to the above method.

[0060] Example 3:

[0061] The conventional super-viscosity wear layer mix has an asphalt-aggregate ratio of 4.8%, a fiber content of 1%, and a paving thickness of 1.2 cm. The grouting material and method for rutting slab cuts are the same as in Example 1.

[0062] Example 4:

[0063] The high-viscosity and high-elasticity wear layer uses the aggregate of Example 1, with an asphalt-aggregate ratio of 6.8%, and high-viscosity and high-elasticity asphalt. The paving thickness is 2cm. The grouting material and method for rutting slabs are the same as in Example 1.

[0064] project Example 1 Example 2 Example 3 Example 4 Anti-slip performance of specimens / BPN 76 83 64 71 60℃, 10,000 compaction cycles, rut slab misalignment height difference / mm 1.2 1.6 2.4 1.1 100,000 accelerated loading cycles rut ​​depth / mm 1.06 0.98 3.4 1.13 Anti-slip performance retention rate after 100,000 accelerated loading cycles / % 89 92 43 94 <![CDATA[1h wet wheel abrasion / g / m 2 > 146 108 487 113 <![CDATA[6d wet wheel wear / g / m 2 > 211 163 792 191

Claims

1. A method for constructing CMCA ultra-thin wearing course pavement, characterized in that, The construction method includes the following steps: ① Assess the pavement quality, and take core samples from the surface layer and base layer where the defects are located to analyze the root cause and extent of the defects; for cracks in the surface layer and base layer, perform crack filling treatment by filling the cracks in the base layer and surface layer with polymer grout material A until the grout material completely penetrates and fills the cracks; for loose base layer defects, use organic-inorganic composite grout material B to form a unified whole; for rutting defects in the surface layer exceeding 5mm, milling and leveling are required. ② After the original road surface has been treated for defects, spray a high-strength bonding layer material evenly at a rate of 0.3-0.6 kg / m². 2 ; ③ After the high-strength adhesive layer material is surface dry, evenly spread a 1.5-2.5cm thick CMCA mixture layer; ④ After the CMCA mixture has dried to the surface, traffic can be opened, thus completing the CMCA ultra-thin wear-resistant layer pavement construction; The polymer grouting material A for the base layer and surface layer is a two-component epoxy resin modified polyurethane material; wherein component 1, by weight, comprises 10-40 parts castor oil, 20-30 parts polyether polyol 1, 5-10 parts polyether polyol 2, 5-10 parts polyester polyol, 5-10 parts prepolymer epoxy resin, 0.1-0.3 parts catalyst, 10-40 parts 400-800 mesh CaCl2 and 10-30 parts ethyl acetate, which are mixed and stirred evenly to achieve a viscosity of 1000-3000 mPa·s at 25°C; component 2, by weight, comprises 50-90 parts crude MDI, 10-30 parts filler and 10-40 parts ethyl acetate, achieving a viscosity of 1000-3000 mPa·s at 25°C. The organic-inorganic composite grouting material B is composed of 20 parts by weight of 50-60% solid content polyacrylate emulsion, 70 parts of silicate cement, 1-2 parts of polystyrene cyclopentadiene water-reducing agent, 8-12 parts of calcium aluminate type expansion agent, 3-4 parts of sulfate type early strength agent and 40 parts of water. The polyether polyol 1 is a propylene glycol condensate; the polyether polyol 2 is polymerized from trimethylolpropane and propylene oxide; the polyester polyol is polymerized from phthalic anhydride and glycerol; the prepolymer epoxy resin is prepared by reacting 70 parts by weight of E51, 30 parts by weight of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, and 13-15 parts by weight of ethylenediamine at room temperature; the catalyst is a mixture of 10 parts by weight of stannous octoate, 10 parts by weight of triethylenediamine, and 10 parts by weight of glycerol. The method for preparing CMCA mixture includes: mixing 100 parts by weight of discontinuously graded aggregate evenly; adding 3-5 parts by weight of water and mixing the aggregate for 15-30 seconds to evenly wet the aggregate; spraying 15-20 parts by weight of modified emulsified asphalt evenly onto the surface of the aggregate and mixing for 30-90 seconds to ensure that the modified emulsified asphalt is evenly coated with the aggregate and that the modified emulsified asphalt is mixed with the mineral powder and fine aggregate until a viscous state is achieved.

2. The CMCA ultra-thin wearing course pavement construction method according to claim 1, characterized in that, The specific operation of the crack grouting treatment is as follows: Drill grouting holes and venting holes at the cracks. The diameter of the holes is 2-5cm, and the distance between the two holes is not less than 50cm. Seal the surface of the remaining cracks with glass glue. After the drilling is completed and the glass glue has cured, mix component 1 and component 2 at a mass ratio of 1:1-1.2 using a coaxial mixing and grouting device and inject them evenly into the grouting holes until the polymer grouting material A for the base layer and surface layer is discharged from the venting holes. Stop grouting when the grouting pressure is 0.5-2MPa.

3. The CMCA ultra-thin wearing course pavement construction method according to claim 1, characterized in that, The high-strength adhesive layer material is composed of 10-30 parts by weight of polyacrylate emulsion with a solid content of 50-60% and 70-90 parts by weight of emulsified SBS modified asphalt with a solid content of 60%.

4. The CMCA ultra-thin wearing course pavement construction method according to claim 1, characterized in that, The modified emulsified asphalt is made by mixing 5-15 parts by weight of waterborne epoxy resin, 5-15 parts by weight of waterborne epoxy amine curing agent, and 70-90 parts by weight of emulsified SBS modified asphalt with a solid content of 60%.

5. The CMCA ultra-thin wearing course pavement construction method according to claim 1, characterized in that, The discontinuously graded stone material is composed of 1-2 parts by weight of 6mm chopped glass fiber, 5-8 parts by weight of mineral powder, 15-25 parts by weight of 1-3mm basalt stone, 50-60 parts by weight of 5-10mm basalt stone, and 10-30 parts by weight of 10-15mm basalt stone.