Cement concrete pavement structure

Abstract

This invention discloses a cement concrete pavement structure for use in vehicular roads, relating to the field of road construction technology. The cement concrete pavement structure includes: a subbase layer composed of graded steel slag; an intermediate base layer composed of cement-stabilized steel slag; a sand cushion layer composed of sand; and a surface layer composed of cement concrete. The subbase layer, intermediate base layer, sand cushion layer, and surface layer are laid from bottom to top. The subbase layer is laid on the roadbed, the intermediate base layer is laid on top of the subbase layer, the sand cushion layer is laid on top of the intermediate base layer, and the surface layer is laid on top of the sand cushion layer. This invention provides a cement concrete pavement structure that can improve the strength of the pavement structure and environmentally treat waste steel slag, thereby improving resource utilization.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to a cement concrete pavement structure utilizing steel slag. Background Technology

[0002] Currently, most factory and mining roads use cement concrete pavement, which has advantages over asphalt pavement such as high rigidity, strong load-bearing capacity, long fatigue life, and low cost. With technological advancements, the loads of transport vehicles passing through factories and mines are increasing, and the frequency of these vehicles crossing the roads is also increasing. Existing pavement structures cannot meet the load-bearing requirements, and pavement damage is becoming increasingly severe, seriously affecting the transportation capacity of factory areas. Factories and mines urgently need a pavement structure with strong load-bearing capacity.

[0003] Meanwhile, steel plants generate a large amount of waste steel slag during steel production, which occupies a lot of space in the plant area. The current utilization rate of waste steel slag is low, and the waste steel slag in the plant area also urgently needs to be recycled and treated. Summary of the Invention

[0004] The purpose of this invention is to provide a cement concrete pavement to solve the problems of insufficient pavement load and steel slag accumulation in the factory area in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A cement concrete pavement structure, comprising:

[0007] The subbase is made of graded steel slag;

[0008] The intermediate base layer is made of cement-stabilized steel slag.

[0009] A sand cushion layer is made of sand particles.

[0010] The surface layer is made of cement concrete;

[0011] The subbase, intermediate base, sand cushion layer and surface layer are laid from bottom to top. The subbase is laid on the roadbed, the intermediate base is laid on the subbase, the sand cushion layer is laid on the intermediate base, and the surface layer is laid on the sand cushion layer.

[0012] In an optional embodiment of this application, the content of particles with a diameter less than 0.075 mm in the graded steel slag of the subbase is ≤5%, the particle diameter of the graded steel slag of the subbase is <31.5 mm, the thickness is 30-40 cm, the compaction degree is ≥0.97, and the 7-day unconfined compressive strength of the base layer is ≥2.5 MPa.

[0013] In an optional embodiment of this application, the base layer comprises several base layers, and the thickness of each base layer is ≤20cm.

[0014] In an optional embodiment of this application, the cement content of the cement-stabilized steel slag in the intermediate base layer is 3% to 5.5%, the particle diameter of the cement-stabilized steel slag is <31.5mm, and the content of particles with a particle diameter less than 0.075 in the cement-stabilized steel slag of the intermediate base layer is ≤2%.

[0015] In an optional embodiment of this application, the cement-stabilized steel slag forms a preliminary intermediate base course after an initial set initial setting time, and the preliminary intermediate base course forms an intermediate base course after an initial set final setting time. The compaction degree of the intermediate base course is ≥0.98, and the 7-day unconfined compressive strength of the base course is ≥4MPa.

[0016] In an optional embodiment of this application, the intermediate base layer includes an upper base layer and a lower base layer, wherein the cement content of the upper base layer is 4.5% to 5.5%, the cement content of the lower base layer is 3% to 4%, and the thickness of the upper base layer and the lower base layer ranges from 16 to 20 cm.

[0017] In an optional embodiment of this application, the thickness of the sand cushion layer is 2 to 3 cm, the sand particle size of the sand cushion layer is less than 10 mm, and the content of sand particles with a particle size > 2 mm in the sand cushion layer is greater than 55%.

[0018] In an optional embodiment of this application, the thickness of the surface layer is 25-35 cm, and the cement concrete of the surface layer includes coarse aggregate, fine aggregate and cement. The coarse aggregate is crushed stone or gravel, and the coarse aggregate has a mud content ≤2%, a water absorption rate ≤3%, and a Los Angeles abrasion loss ≤35%. The fine aggregate is natural sand or manufactured sand, and the fine aggregate has a mud content ≤3%, a water absorption rate ≤2%, and a chloride ion content ≤0.06%.

[0019] In optional embodiments of this application, the cement concrete pavement structure further includes:

[0020] The curb layer is made of cement concrete curb stones, which are set on both sides of the surface layer and are higher than the surface layer.

[0021] The curb backrest is made of cement concrete and has a receiving groove for accommodating the curb layer. The curb layer is placed in the receiving groove, and the curb backrest is connected to the intermediate base layer.

[0022] In an optional embodiment of this application, the receiving groove includes a groove bottom and a groove back, the curb layer is in contact with the groove back, and a mortar pad layer is provided between the curb layer and the groove bottom, the material of the mortar pad layer being cement mortar.

[0023] The beneficial effects of the cement concrete pavement structure disclosed in this invention are as follows: Using cement concrete for the surface layer improves its load-bearing capacity and service life. A sand cushion layer composed of sand particles is placed between the surface layer and the intermediate base layer to buffer the load transfer between them and ensure uniform stress distribution, effectively preventing surface layer fracture. The subbase layer, constructed from graded steel slag, prevents groundwater erosion of the intermediate base layer, thus mitigating its performance. It also acts as a stress buffer between the intermediate base layer and the subgrade, preventing cracks in the intermediate base layer from reflecting back to the surface layer, thereby improving overall durability. The intermediate base layer, constructed from cement-stabilized steel slag, forms a semi-rigid structure. Replacing traditional cement-stabilized crushed stone with cement-stabilized steel slag not only reduces the mining and utilization of natural non-renewable stone but also increases the utilization rate of waste steel slag, achieving material savings and environmentally friendly waste steel slag treatment. In terms of mechanical properties, cement-stabilized steel slag has higher molding strength and better bonding performance than cement-stabilized crushed stone, significantly improving overall load-bearing capacity and durability. The structure of subbase, intermediate base, sand cushion, and surface layer greatly enhances the overall load-bearing capacity and durability. Furthermore, by replacing traditional cement-stabilized crushed stone with cement-stabilized steel slag in the intermediate base, waste steel slag is utilized rationally and environmentally, avoiding pollution and improving resource utilization. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a cement concrete pavement structure according to the present invention.

[0026] The reference numerals are as follows: 10, subbase; 20, intermediate base; 21, lower base; 22, upper base; 30, sand cushion; 40, surface layer; 50, curb layer; 60, curb backing; 61, receiving groove; 611, groove bottom; 612, groove back; 70, mortar cushion; 80, ground subgrade. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art. The drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0032] The following is in conjunction with the appendix to this instruction manual. Figure 1 The preferred embodiments disclosed in this invention will be further described in detail below.

[0033] Please refer to Figure 1This application provides a cement concrete pavement structure that can be applied to road transportation in steel plant areas. Through the arrangement of a subbase 10, intermediate base 20, sand cushion 30, and surface layer 40, the subbase 10 serves to block groundwater infiltration, the intermediate base 20 plays a major load-bearing role, and the intermediate base 20 uses cement-stabilized steel slag instead of cement-stabilized crushed stone, thus environmentally treating waste steel slag while saving on the use of non-renewable crushed stone, improving resource utilization and environmental performance. The sand cushion 30 buffers the load transfer between the surface layer 40 and the intermediate base 20, ensuring uniform stress distribution between them, effectively preventing surface layer 40 fracture, and greatly improving the overall load-bearing capacity and durability.

[0034] In this embodiment of the application, a cement concrete pavement structure includes:

[0035] The subbase layer 10 is made of graded steel slag.

[0036] The intermediate base layer 20 is laid with cement-stabilized steel slag.

[0037] Sand cushion layer 30 is made of sand particles;

[0038] The surface layer 40 is made of cement concrete;

[0039] The subbase 10, intermediate base 20, sand cushion 30 and surface layer 40 are laid from bottom to top. The subbase 10 is laid on the roadbed, the intermediate base 20 is laid on the subbase 10, the sand cushion 30 is laid on the intermediate base 20, and the surface layer 40 is laid on the sand cushion 30.

[0040] The subbase 10 prevents groundwater erosion of the intermediate base 20, ensuring the stability of the intermediate base 20 used for load bearing. The intermediate base 20 uses cement-stabilized steel slag instead of cement-stabilized crushed stone, effectively improving the stability, cohesion, and load bearing capacity of the intermediate base 20. The sand cushion layer 30 plays a good role in buffering the load and distributing the stress evenly. Furthermore, the fracture of the intermediate base 20 will not be transmitted upward to the surface layer 40 through the sand cushion layer 30, thus protecting the surface layer 40. The surface layer 40 is paved with cement concrete, which improves the load bearing capacity and service life of the surface layer 40. Through the interaction between the various layers, the overall load bearing capacity and durability are effectively improved.

[0041] The graded steel slag in subbase 10 contains ≤5% particles with a diameter less than 0.075mm, and particles with a diameter <31.5mm. The thickness is 30–40cm, and the 7-day unconfined compressive strength is ≥2.5MPa. The graded steel slag is designed using heavy compaction standards, with a compaction degree ≥0.97 and a CBR value ≥80%. The gradation range of the graded steel slag mixture used in subbase 10 is shown in Table 1.

[0042] Table 1. Gradation range of steel slag mixture for subbase course.

[0043]

[0044] The subbase 10 is laid with graded steel slag to prevent groundwater from the ground subgrade 80 from seeping upwards to the intermediate base 20, ensuring the performance stability of the cement-stabilized steel slag in the intermediate base 20. The subbase 10 also uses graded steel slag instead of crushed stone, effectively utilizing waste steel slag, improving the resource utilization rate of waste steel slag, and achieving the effect of environmental protection.

[0045] The subbase 10 comprises several subbase layers, each with a layer thickness of ≤20cm. The subbase 10 is compacted layer by layer through subbase layering, resulting in stronger compaction and improved performance stability of the graded steel slag in the subbase 10.

[0046] The cement content of the cement-stabilized steel slag in the intermediate base layer 20 is 3% to 5.5%, the particle diameter of the cement-stabilized steel slag is <31.5mm, and the content of particles with a diameter less than 0.075mm in the cement-stabilized steel slag of the intermediate base layer 20 is ≤2%. The cement content of the cement-stabilized steel slag in the intermediate base layer 20 is between 3% and 5.5% to ensure the bonding ability between the cement-stabilized steel slag particles, and the particle diameter of the cement-stabilized steel slag is within the set range to ensure good fluidity when the cement-stabilized steel slag is laid to form the intermediate base layer 20, improving the flatness after laying and compaction.

[0047] Cement-stabilized steel slag forms a preliminary intermediate base course after an initial set setting time. This preliminary intermediate base course, after an initial set final setting time, forms intermediate base course 20. Intermediate base course 20 has a compaction degree ≥0.98 and a 7-day unconfined compressive strength ≥4MPa. The initial set setting time is 3–5 hours. During this time, the cement-stabilized steel slag forms the preliminary intermediate base course, which has a certain degree of hardness, but the cement is not yet fully solidified, and the cement-stabilized steel slag still has some fluidity. Under heavy pressure, the preliminary intermediate base course is prone to deformation. The initial set final setting time is 6–10 hours. At this time, the cement is fully solidified, the cement-stabilized steel slag no longer has fluidity, and its hardness reaches its maximum. By undergoing both initial and final setting, the cement-stabilized steel slag forms intermediate base course 20 with higher overall hardness and stronger stability.

[0048] The intermediate base layer 20 comprises an upper base layer 22 and a lower base layer 21. The cement content of the upper base layer 22 is 4.5%–5.5%, and the cement content of the lower base layer 21 is 3%–4%. The thickness of both the upper and lower base layers 22 and 21 ranges from 16 to 20 cm. The layered arrangement of the upper and lower base layers 22 and 21 effectively enhances the compaction strength when the intermediate base layer 20 is thicker, thereby improving its overall strength. The higher cement content of the upper base layer 22 results in stronger setting properties and better crack resistance, effectively preventing cracks in the upper base layer 22 from being transmitted to the surface layer 40, thus improving overall durability.

[0049] The cement-stabilized steel slag gradation of the upper base layer 22 is shown in Table 2.

[0050] Table 2 Cement Stabilized Steel Slag Gradation Table for Upper Base Layer

[0051]

[0052] The cement-stabilized steel slag gradation of the lower base layer 21 is shown in Table 3:

[0053] Table 3 Cement-Stabilized Steel Slag Gradation Table for Subgrade

[0054]

[0055] The cement-stabilized steel slag gradation of the upper base course 22 and the lower base course 21 is the same, which gives the upper base course 22 and the lower base course 21 good adhesion and enhances the strength of the intermediate base course 20 formed by the upper base course 22 and the lower base course 21.

[0056] The thickness of the sand cushion layer 30 ranges from 2 to 3 cm. The sand particles in the sand cushion layer 30 have a particle size of less than 10 mm, and the content of sand particles with a particle size > 2 mm is greater than 55%. The small and uniform particle size of the sand particles improves the fluidity of the sand cushion layer 30. The thickness of the sand cushion layer 30 is 2 to 3 cm to ensure its buffering effect while avoiding excessive thickness that would weaken the overall stability. The mud content of the sand particles is less than 4%. Mud would hinder the flow of sand particles, and the low mud content can ensure the fluidity of the sand cushion layer 30 and improve the uniform force distribution of the load of the surface layer 40 to the intermediate base layer 20.

[0057] The surface layer 40 has a thickness of 25–35 cm. The cement concrete of the surface layer 40 includes coarse aggregate, fine aggregate, and cement. The coarse aggregate is crushed stone or gravel with a mud content ≤2%, water absorption ≤3%, and Los Angeles abrasion loss ≤35%. The fine aggregate is natural sand or manufactured sand with a mud content ≤3%, water absorption ≤2%, and chloride ion content ≤0.06%. As a structure in contact with the load-bearing object, the surface layer 40 needs to have stable load-bearing capacity. The surface layer 40 is composed of a mixture of primary aggregate, fine aggregate, and cement to ensure fluidity during laying, thereby ensuring good flatness after laying and improving the strength of the surface layer 40.

[0058] Cement concrete pavement structures also include:

[0059] The curb layer 50 is made of cement concrete curb stones with a strength grade ≥ C40. The curb layer 50 extends 5–15 cm above the surface layer 40, and is positioned on both sides of the surface layer 40. The curb layer 50 protects the surface layer 40, preventing direct exposure of its sides and thus avoiding cracking that could affect the overall strength of the surface layer 40. Simultaneously, the curb layer 50's elevation also helps prevent large-scale intrusion of roadside sand and gravel into the surface layer 40, improving its surface cleanliness and preventing sharp sand and gravel from damaging the surface layer 40 and affecting its strength.

[0060] The curb backrest 60 is made of cement concrete with a strength grade ≥ C25. It is equipped with a receiving groove 61 to accommodate the curb layer 50. The curb layer 50 is placed in the receiving groove 61. The curb backrest 60 is connected to the intermediate base layer 20. The curb backrest 60 supports the curb layer 50, so that the curb layer 50 is close to the side of the surface layer 40, thereby improving the stability of the curb layer 50.

[0061] The receiving trough 61 includes a trough bottom 611 and a trough back 612. The curb layer 50 is connected to the trough back 612. A mortar pad 70 is provided between the curb layer 50 and the trough bottom 611. The mortar pad 70 is made of cement mortar. The bottom 611 of the curb back 60 receiving trough 61 is connected to the curb layer 50 through the mortar pad 70, enhancing the fixation of the curb layer 50. The mortar pad 70 is 2-3 cm thick, with a cement to sand mass ratio of 1:3, a particle size smaller than 2 mm exceeding 45%, and a mud content ≤4%.

[0062] The construction process of the above-mentioned cement concrete pavement structure is as follows:

[0063] S10 is a test section to determine construction parameters such as the laying thickness, number of compaction passes, and settlement difference of the ground subgrade 80, subbase 10, and intermediate base 20.

[0064] S20 uses a vibratory roller to compact the bottom surface in layers to form a ground subgrade 80, in order to achieve the required compaction degree and resilient modulus.

[0065] S30 graded steel slag is compacted in layers to form a subbase layer 10, ensuring each layer has a compaction degree of 0.97 or higher. During compaction, it is advisable to start with light compaction and gradually increase the intensity and speed, working from the edges to the center. For superelevated sections of ramps and curves, compaction should proceed from the inside to the outside, starting with lower sections and gradually increasing in elevation. The compaction paths of adjacent compaction passes should overlap by 1 / 3 of the wheel width to maintain uniform compaction and prevent missed areas. For corners and edges that cannot be compacted, manual labor or small machinery should be used for tamping.

[0066] S40 is a layered and compacted intermediate base course 20 formed by spreading and rolling the mud-stabilized steel slag in layers, so that the compaction degree of each layer reaches more than 0.98, and the intermediate base course 20 needs to be cured with a preliminary set initial setting time and a preliminary set final setting time.

[0067] S50, after the intermediate base layer 20 is cured, spread 2-3cm of sand evenly to form a sand cushion layer 30.

[0068] S60 involves layering and compacting cement concrete to form surface layer 40, with additional transverse joints, longitudinal joints, and construction joints to increase surface friction. The transverse joint spacing is 4–6 m, the joint width is 3–8 m, and the depth is 10–12 mm. Tie rods are installed according to specifications. The length-to-width ratio of surface layer 40 does not exceed 1.35, and the plane area does not exceed 25 m². The longitudinal joint spacing is 3–4.5 m, the joint width is 3–8 m, and the depth is 6–7.5 mm. Tie rods are also installed according to specifications.

[0069] S70, after the cement concrete surface layer 40 has been cured to the required strength, curb backrests 60 are set on both sides of the road, and receiving grooves 61 are set. A 2-3cm mortar pad layer 70 is laid at the bottom 611 of the receiving groove 61. The curb stones are constructed and fixed in the receiving groove 61 to form the curb layer 50. The top line of the curb stones should be smooth, the gaps between the curb stones should be uniform, dense and flat, and the top surface of the curb stones should be flat and straight and meet the height requirements.

[0070] In summary, using cement concrete to pave the surface layer 40 improves its load-bearing capacity and service life. A sand cushion layer 30, composed of sand particles, is placed between the surface layer 40 and the intermediate base layer 20 to buffer the load transfer between them and ensure uniform stress distribution, effectively preventing surface layer 40 cracking. The subbase layer 10, constructed from graded steel slag, prevents groundwater erosion of the intermediate base layer 20, thus protecting its performance. It also acts as a stress buffer between the intermediate base layer 20 and the ground subgrade 80, preventing cracks in the intermediate base layer 20 from reflecting back to the surface layer 40, thereby improving overall durability. The intermediate base layer 20 is constructed using cement-stabilized steel slag, forming a semi-rigid structure. By replacing traditional cement-stabilized crushed stone with cement-stabilized steel slag, it not only reduces the mining and utilization of natural non-renewable stone but also improves the utilization rate of waste steel slag, achieving material conservation and environmentally friendly waste steel slag treatment. In terms of mechanical properties, cement-stabilized steel slag has higher molding strength and better bonding performance than cement-stabilized crushed stone, significantly improving the overall load-bearing capacity and durability. The structure of the subbase layer 10, intermediate base layer 20, sand cushion layer 30, and surface layer 40 greatly enhances the overall load-bearing capacity and durability. Furthermore, by replacing traditional cement-stabilized crushed stone with cement-stabilized steel slag in the intermediate base layer 20, waste steel slag is utilized rationally and environmentally, avoiding environmental pollution and improving resource utilization.

[0071] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0072] Although this disclosure has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Because this disclosure can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A cement concrete pavement structure, characterized in that, include: The subbase is made of graded steel slag, wherein the content of particles with a diameter less than 0.075mm in the graded steel slag of the subbase is ≤5%, the particle diameter of the graded steel slag of the subbase is <31.5mm, the thickness is 30~40cm, the compaction degree is ≥0.97, and the 7-day unconfined compressive strength of the base layer is ≥2.5MPa. The intermediate base layer is made of cement-stabilized steel slag, wherein the cement content of the cement-stabilized steel slag in the intermediate base layer is 3%~5.5%, the particle diameter of the cement-stabilized steel slag is <31.5mm, and the content of particles with a particle diameter less than 0.075mm in the cement-stabilized steel slag in the intermediate base layer is ≤2%. The sand cushion layer is composed of sand particles, the thickness of which ranges from 2 to 3 cm, the particle size of which is less than 10 mm, and the content of sand particles with a particle size > 2 mm is greater than 55%. The surface layer is made of cement concrete with a thickness of 25-35cm. The cement concrete of the surface layer includes coarse aggregate, fine aggregate, and cement. The coarse aggregate is crushed stone or gravel with a mud content ≤2%, water absorption ≤3%, and Los Angeles abrasion loss ≤35%. The fine aggregate is natural sand or manufactured sand with a mud content ≤3%, water absorption ≤2%, and chloride ion content ≤0.06%. The subbase, intermediate base, sand cushion layer and surface layer are laid from bottom to top. The subbase is laid on the roadbed, the intermediate base is laid on the subbase, the sand cushion layer is laid on the intermediate base, and the surface layer is laid on the sand cushion layer.

2. The cement concrete pavement structure according to claim 1, characterized in that, The subbase consists of several subbase layers, and the thickness of each subbase layer is ≤20cm.

3. The cement concrete pavement structure according to claim 1, characterized in that, The cement-stabilized steel slag forms a preliminary intermediate base course after an initial set initial setting time. The preliminary intermediate base course forms an intermediate base course after an initial set final setting time. The compaction degree of the intermediate base course is ≥0.98, and the 7-day unconfined compressive strength of the base course is ≥4MPa.

4. A cement concrete pavement structure according to claim 3, characterized in that, The intermediate base layer includes an upper base layer and a lower base layer. The cement content of the upper base layer is 4.5% to 5.5%, the cement content of the lower base layer is 3% to 4%, and the thickness of the upper and lower base layers ranges from 16 to 20 cm.

5. A cement concrete pavement structure according to any one of claims 1-4, characterized in that, Cement concrete pavement structures also include: The curb layer is made of cement concrete curb stones, which are set on both sides of the surface layer and are higher than the surface layer. The curb backrest is made of cement concrete and has a receiving groove for accommodating the curb layer. The curb layer is placed in the receiving groove, and the curb backrest is connected to the intermediate base layer.

6. A cement concrete pavement structure according to claim 5, characterized in that, The receiving trough includes a trough bottom and a trough back, the curb layer is connected to the trough back, and a mortar pad layer is provided between the curb layer and the trough bottom, the material of the mortar pad layer being cement mortar.

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