A thickness optimization method for low-carbon durable super-large particle size cement stabilized macadam base

Abstract

The application discloses a thickness optimization method for low-carbon durable super-large particle size cement stabilized macadam base, and comprises the following steps: establishing a semi-rigid base asphalt pavement calculation model and a super-large particle size cement stabilized macadam base asphalt pavement calculation model of a target project; determining the compression resilience modulus of asphalt mixture, and determining the resilience modulus and bending tensile strength of semi-rigid base material and super-large particle size cement stabilized macadam; calculating the maximum tensile stress of the bottom of each layer of the semi-rigid base S 1 S 2 S 1 S 2 S 1 S 2 ; finally, the optimal thickness of the super-large particle size cement stabilized macadam base obtained through optimization is (H H +2) cm.

Description

Technical Field

[0001] This invention belongs to the field of transportation civil engineering technology, specifically relating to a method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course. Background Technology

[0002] Cement-stabilized crushed stone with a nominal maximum particle size exceeding 53mm is also known as ultra-large particle size cement-stabilized crushed stone. Compared to traditional cement-stabilized crushed stone, it has advantages such as strong crack resistance, high strength, and low cement dosage, thus exhibiting superior durability and low-carbon environmental benefits. In recent years, ultra-large particle size cement-stabilized crushed stone has been increasingly used in semi-rigid base asphalt pavements of high-grade highways. However, the stress state of ultra-large particle size cement-stabilized crushed stone base courses in asphalt pavement structures is inevitably significantly different from that of traditional cement-stabilized crushed stone base courses. Obviously, directly applying the structural form of traditional cement-stabilized crushed stone base asphalt pavements to ultra-large particle size cement-stabilized crushed stone base asphalt pavements can easily lead to unreasonable stress distribution or unnecessary material waste.

[0003] Therefore, it is necessary to optimize the thickness of ultra-large particle size cement-stabilized crushed stone base course to ensure the mechanical properties of the pavement structure, save raw materials, and reduce engineering costs. However, this has not been addressed in existing literature or publicly available information. Summary of the Invention

[0004] The purpose of this invention is to provide a method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, thereby optimizing the thickness of the ultra-large particle size cement-stabilized crushed stone base course to ensure the mechanical properties of the pavement structure, save raw materials, and reduce engineering costs.

[0005] To achieve the above objectives, the technical solution adopted in this invention is: a method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, specifically implemented according to the following steps: Step 1: Use pavement calculation software based on the theory of elastic layered systems to establish a calculation model for the semi-rigid base asphalt pavement and an ultra-large particle size cement-stabilized crushed stone base asphalt pavement of the target project. Step 2: Determine the compressive resilient modulus of asphalt mixtures, and determine the resilient modulus and flexural strength of semi-rigid base materials and ultra-large diameter cement-stabilized crushed stone. Step 3: The load calculation adopts the standard axle load BZZ-100 of the double circular uniformly distributed vertical load, and the calculation point is selected at the center position of the double circular uniformly distributed vertical load. Step 4: Import the compressive resilient modulus of the asphalt mixture and the resilient modulus of the semi-rigid base material of the target project into the semi-rigid base asphalt pavement calculation model, calculate the tensile stress at the bottom of each layer of the semi-rigid base, and record the maximum value. s 1. Calculate according to formula (1) to obtain the result. S1; (1) in, s This represents the maximum tensile stress at the bottom of the base layer, in MPa. B The tensile strength of the semi-rigid base material, in MPa; Step 5: Import the compressive resilient modulus of the asphalt mixture and the resilient modulus of the ultra-large diameter cement-stabilized crushed stone into the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement. Calculate the tensile stress at the bottom of each layer of the ultra-large diameter cement-stabilized crushed stone base and record the maximum value. s 2. Calculate according to formula (1) to obtain the result. S 2; Step 6, if S 1> S 2. Reduce the total thickness of the ultra-large diameter cement-stabilized crushed stone base course in the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement by 2 cm. Repeat step 5 until... S 1< S 2. At this point, the total thickness of the ultra-large particle size cement-stabilized crushed stone base course is: H cm; Step 7, finally, the optimal thickness of the ultra-large particle size cement-stabilized crushed stone base course is ( H +2)cm.

[0006] As a preferred technical solution of the present invention, the road surface calculation software is BISA.

[0007] As a preferred technical solution of the present invention, in step 2, the day resilient modulus of the semi-rigid base material and the ultra-large particle size cement-stabilized crushed stone is measured to be the 90-day resilient modulus.

[0008] As a preferred technical solution of the present invention, in step 2, the flexural strength of the semi-rigid base material and the ultra-large particle size cement-stabilized crushed stone is measured to be the 90-day flexural strength.

[0009] The beneficial effects of this invention are: the method for optimizing the thickness of a low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course helps to obtain the optimal thickness of the ultra-large particle size cement-stabilized crushed stone base course, prevents unreasonable stress distribution or unnecessary material waste in the ultra-large particle size cement-stabilized crushed stone base course, and ensures project quality and maximizes economic benefits. Attached Figure Description

[0010] Figure 1 The compressive resilient modulus of the asphalt mixture and the 90-day resilient modulus of the ultra-large diameter cement-stabilized crushed stone are obtained in the application examples. Figure 2 This is a schematic diagram of step 3 in the application example. Detailed Implementation

[0011] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] The present invention provides a method for optimizing the thickness of a low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, which is implemented according to the following steps: Step 1: Use pavement calculation software based on the theory of elastic layered systems to establish a calculation model for the semi-rigid base asphalt pavement and an ultra-large particle size cement-stabilized crushed stone base asphalt pavement of the target project. Step 2: Determine the compressive resilient modulus of asphalt mixtures, and determine the 90-day resilient modulus and 90-day flexural strength of semi-rigid base materials and ultra-large diameter cement-stabilized crushed stone. Step 3: The load calculation adopts the standard axle load BZZ-100 of the double circular uniformly distributed vertical load, and the calculation point is selected at the center position of the double circular uniformly distributed vertical load. Step 4: Import the compressive resilient modulus of the asphalt mixture and the 90-day resilient modulus of the semi-rigid base material of the target project into the semi-rigid base asphalt pavement calculation model, calculate the tensile stress at the bottom of each layer of the semi-rigid base, and record the maximum value. s 1. Calculate according to formula (1) to obtain the result. S 1; (1) in, s This represents the maximum tensile stress at the bottom of the base layer, in MPa. B The 90-day flexural tensile strength of the semi-rigid base material, in MPa; Step 5: Import the compressive resilient modulus of the asphalt mixture and the 90-day resilient modulus of the ultra-large diameter cement-stabilized crushed stone into the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement. Calculate the tensile stress at the bottom of each layer of the ultra-large diameter cement-stabilized crushed stone base and record the maximum value. s 2. Calculate according to formula (1) to obtain the result. S 2; Step 6, if S 1> S 2. Reduce the total thickness of the ultra-large diameter cement-stabilized crushed stone base course in the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement by 2 cm. Repeat step 5 until... S 1< S 2. At this point, the total thickness of the ultra-large particle size cement-stabilized crushed stone base course is: H cm; Step 7, finally, the optimal thickness of the ultra-large particle size cement-stabilized crushed stone base course is ( H +2)cm.

[0013] Application examples According to the technical solution of the present invention, this embodiment provides a method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, taking the Yaoluanxi Expressway as an example.

[0014] The present invention provides a method for optimizing the thickness of a low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, which is implemented according to the following steps: Step 1: Use BISA pavement calculation software to establish a calculation model for the semi-rigid base asphalt pavement and an ultra-large particle size cement-stabilized crushed stone base asphalt pavement of the target project. Step 2: Determine the compressive resilient modulus of the asphalt mixture according to the method specified in the current standard "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering (JTG E20-2011)" (see...). Figure 1 (a) The 90-day resilient modulus of semi-rigid base course material (CTB-30) and ultra-large particle size cement-stabilized crushed stone (CTB-50) was determined according to the method of the current specification "Test Procedure for Inorganic Binder Stabilized Materials in Highway Engineering (JTG E51-2009)" (see Figure 1 (b) and 90-day flexural strength (respectively) B 1 = 1.96 MPa and B 2 = 2.20 MPa); Step 3: The load calculation uses the standard axle load BZZ-100, a double-circle uniformly distributed vertical load. The calculation point is selected at the center of the double-circle uniformly distributed vertical load. See [link / reference]. Figure 2 ; Step 4: Import the compressive resilient modulus of the asphalt mixture and the 90-day resilient modulus of the semi-rigid base material of the target project into the semi-rigid base asphalt pavement calculation model, calculate the tensile stress at the bottom of each layer of the semi-rigid base, and record the maximum value. s 1 = 0.1670 MPa, and the result is obtained by calculating according to formula (1). S 1, S 1= s 1 / B 1 = 0.1670 MPa / 1.96 MPa = 0.085; (1) in, s This represents the maximum tensile stress at the bottom of the base layer, in MPa. B The 90-day flexural tensile strength of the semi-rigid base material, in MPa; Step 5: Import the compressive resilient modulus of the asphalt mixture and the 90-day resilient modulus of the ultra-large diameter cement-stabilized crushed stone into the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement. Calculate the tensile stress at the bottom of each layer of the ultra-large diameter cement-stabilized crushed stone base and record the maximum value. s 2. Calculate according to formula (1) to obtain the result. S 2; Step 6, if S 1> S 2. Reduce the total thickness of the ultra-large diameter cement-stabilized crushed stone base course in the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement by 2 cm. Repeat step 5 until... S 1< S 2. The calculation results are shown in Table 1. Table 1 shows that when the total thickness of the ultra-large particle size cement-stabilized crushed stone base course is... H When =46cm, S 2=0.090> S 1 = 0.085; Table 1. Calculation results of the calculation model for asphalt pavement with ultra-large particle size cement-stabilized crushed stone base. Step 7: Finally, the optimal thickness of the ultra-large particle size cement-stabilized crushed stone base course is 46cm + 2cm = 48cm.

[0015] In summary, compared with the original pavement structure thickness, the thickness of the ultra-large particle size cement-stabilized crushed stone base course optimized by this invention is reduced by 6cm while ensuring the mechanical response of the pavement structure. This will save a lot of raw materials and speed up the project progress, bringing significant economic benefits to the project. This proves that the low-carbon, durable ultra-large particle size cement-stabilized crushed stone base course thickness optimization method of this invention has good effects.

[0016] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course, characterized in that, Implement the specific steps as follows: Step 1: Use pavement calculation software based on the theory of elastic layered systems to establish a calculation model for the semi-rigid base asphalt pavement and an ultra-large particle size cement-stabilized crushed stone base asphalt pavement of the target project. Step 2: Determine the compressive resilient modulus of asphalt mixtures, and determine the resilient modulus and flexural strength of semi-rigid base materials and ultra-large diameter cement-stabilized crushed stone. Step 3: The load calculation adopts the standard axle load BZZ-100 of the double circular uniformly distributed vertical load, and the calculation point is selected at the center position of the double circular uniformly distributed vertical load. Step 4: Import the compressive resilient modulus of the asphalt mixture and the resilient modulus of the semi-rigid base material of the target project into the semi-rigid base asphalt pavement calculation model, calculate the tensile stress at the bottom of each layer of the semi-rigid base, and record the maximum value. σ 1. Calculate according to formula (1) to obtain the result. S 1; （1） in, σ This represents the maximum tensile stress at the bottom of the base layer, in MPa. B The tensile strength of the semi-rigid base material, in MPa; Step 5: Import the compressive resilient modulus of the asphalt mixture and the resilient modulus of the ultra-large diameter cement-stabilized crushed stone into the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement. Calculate the tensile stress at the bottom of each layer of the ultra-large diameter cement-stabilized crushed stone base and record the maximum value. σ 2. Calculate according to formula (1) to obtain the result. S 2; Step 6, if S 1> S 2. Reduce the total thickness of the ultra-large diameter cement-stabilized crushed stone base course in the calculation model of the ultra-large diameter cement-stabilized crushed stone base asphalt pavement by 2 cm. Repeat step 5 until... S 1< S 2. At this point, the total thickness of the ultra-large particle size cement-stabilized crushed stone base course is: H cm; Step 7, finally, the optimal thickness of the ultra-large particle size cement-stabilized crushed stone base course is ( H +2)cm.

2. The method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course according to claim 1, characterized in that, In step 1, the road surface calculation software is BISA.

3. The method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course according to claim 2, characterized in that, In step 2, the day resilient modulus of the semi-rigid base material and the ultra-large particle size cement-stabilized crushed stone is measured to be the 90-day resilient modulus.

4. The method for optimizing the thickness of low-carbon, durable, ultra-large particle size cement-stabilized crushed stone base course according to claim 3, characterized in that, In step 2, the flexural strength of the semi-rigid base material and the ultra-large particle size cement-stabilized crushed stone is measured as the 90-day flexural strength.

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