A multifunctional splicing structure suitable for whitetopping pavement reconstruction and expansion

Abstract

The application discloses a kind of multifunctional splicing structure suitable for white plus black pavement reconstruction and expansion, and relates to the technical field of road engineering, including pull rod, balance beam, high water permeable concrete belt, old road pavement structure includes from top to bottom set asphalt overlay, old cement board, old road water stable base layer and old road graded gravel cushion layer, expansion pavement structure includes from top to bottom set expansion asphalt surface layer, roller compacted concrete slab, water stable lower base layer, water stable bottom base layer and expansion road graded gravel cushion layer, asphalt overlay is connected with expansion asphalt surface layer, old cement board is connected with roller compacted concrete slab, one end of pull rod is located in old cement board, the other end of pull rod is located in roller compacted concrete slab, balance beam is located below old cement board and roller compacted concrete slab, high water permeable concrete belt is located below balance beam.The application solves the quality defects such as cracking, deformation, internal water damage and the like at the splicing place of new and old pavement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to a multifunctional splicing structure suitable for white plus black pavement reconstruction and expansion. BACKGROUND

[0002] With the rapid economic development, the traffic volume of expressway exceeds the original predicted traffic volume, and the original expressway needs to be upgraded and reconstructed when it cannot meet the traffic demand, generally splicing and expanding on the basis of the existing expressway. Under the conditions of high temperature and heavy rainfall climate in the south and heavy traffic load, the new and old road splicing place is prone to uneven settlement, poor drainage, cracking and other diseases. The original pavement construction time is relatively long, and the operation time is long. After excavation, it is found that the old road base layer and cushion layer are loose at the edge, and if the new and old road splicing is carried out in the form of excavation steps, it is difficult to guarantee the quality of step excavation, and the defects of splicing place will lead to pavement diseases. The thickness of the old road pavement structure and the new spliced wide pavement structure is inconsistent, there is a height difference at the splicing place of the gravel cushion layer, the interlayer drainage is poor, and the internal water accumulation of the pavement structure leads to water damage and other diseases of the pavement. The current pavement structure layer generally adopts flexible asphalt surface layer plus semi-rigid water stable base layer, while the old road is white plus black pavement structure, the deformation modulus of the new and old road base structure is greatly different, and the internal structure of the new and old road after splicing is prone to deformation and leads to pavement cracking and other diseases. SUMMARY

[0003] The purpose of the present application is to provide a multifunctional splicing structure suitable for white plus black pavement reconstruction and expansion, to solve the problems existing in the prior art, to adopt the splicing of roller compacted concrete plate and old cement plate, to set a balance beam and a high water permeable concrete belt under the new and old road splicing structure, to play multiple functions such as bearing, anti-cracking, anti-deformation and connected drainage system, and to solve the quality defects such as cracking, deformation and internal water damage of the new and old road pavement splicing place.

[0004] To achieve the above purpose, the present application provides the following scheme:

[0005] The application provides a multifunctional splicing structure suitable for blacktopping pavement reconstruction and expansion, which comprises an old road pavement structure, an expansion pavement structure, a pull rod, a balance beam, a high water permeable concrete belt, the old road pavement structure comprises, from top to bottom, an asphalt overlay, an old cement slab, an old road stabilized base and an old road graded gravel cushion, the expansion pavement structure comprises, from top to bottom, an expansion asphalt surface layer, a roller compacted concrete slab, a stabilized lower base, a stabilized bottom base and an expansion road graded gravel cushion, the asphalt overlay is connected with the expansion asphalt surface layer, the old cement slab is connected with the roller compacted concrete slab, one end of the pull rod is located in the old cement slab, the other end of the pull rod is located in the roller compacted concrete slab, the balance beam is located at the bottom of the joint between the old cement slab and the roller compacted concrete slab, and the balance beam is located between the old road stabilized base, the old road graded gravel cushion, the stabilized lower base and the stabilized bottom base, the high water permeable concrete belt is arranged at the bottom of the balance beam, and the high water permeable concrete belt is located between the old road graded gravel cushion, the stabilized bottom base and the expansion road graded gravel cushion.

[0006] Preferably, the thickness of the asphalt overlay and the expansion asphalt surface layer is the same, and the upper surfaces of the asphalt overlay and the expansion asphalt surface layer are arranged flush; the thickness of the old cement slab and the roller compacted concrete slab is the same, and the upper surfaces of the old cement slab and the roller compacted concrete slab are arranged flush; and the joint between the asphalt overlay and the expansion asphalt surface layer is arranged staggered with the joint between the old cement slab and the roller compacted concrete slab.

[0007] Preferably, the top surface of the joint between the old cement slab and the roller compacted concrete slab is provided with a polyester glass cloth, and the width of the polyester glass cloth located on the old cement slab is the same as the width of the polyester glass cloth located on the roller compacted concrete slab.

[0008] Preferably, one side of the balance beam is connected with the old road stabilized base and the old road graded gravel cushion, the other side of the balance beam is connected with the stabilized lower base and the stabilized bottom base, and the upper surfaces of the balance beam, the old road stabilized base and the stabilized lower base are arranged flush.

[0009] Preferably, the balance beam is a concrete structure, and the thickness of the balance beam is the sum of the thickness of the old road stabilized base and the thickness of one of the old road graded gravel cushions.

[0010] Preferably, the thickness of the high water permeable concrete belt is the sum of two-thirds of the thickness of the old road graded gravel cushion, the distance between the lower surface of the old road graded gravel cushion and the upper surface of the expanded road graded gravel cushion, and two-thirds of the thickness of the expanded road graded gravel cushion; the compressive strength of the high water permeable concrete belt is not less than 10 MPa; and the porosity of the high water permeable concrete belt is not less than 20%.

[0011] Preferably, a plurality of pull rod holes are arranged at equal intervals along the longitudinal direction of the old cement board, and the pull rod holes are provided with anchoring adhesive, and one end of each pull rod extends into one pull rod hole.

[0012] Preferably, the depth of the pull rod extending into the old cement board is 20 cm, the height of the pull rod from the bottom of the old cement board is 10-12 cm, and the length of the pull rod in the roller compacted concrete board is 50-60 cm.

[0013] Preferably, the application further comprises an old road subgrade and an expanded road subgrade, the old road subgrade is located below the old road graded gravel cushion, the expanded road subgrade is located below the expanded road graded gravel cushion, the old road subgrade and the expanded road subgrade are connected, the high water permeable concrete belt is connected with the old road subgrade, and the high water permeable concrete belt is located on the top surface of the joint between the old road subgrade and the expanded road subgrade.

[0014] Preferably, the concrete composition of the balance beam comprises 360-400 parts of Portland cement, 737-757 parts of sand, 1101-1141 parts of stone, 132-172 parts of water, and 3.5-4.1 parts of water reducing agent by mass fraction; and the concrete composition of the high water permeable concrete belt comprises 381-401 parts of Portland cement, 1530-1590 parts of stone, and 119-139 parts of water.

[0015] The application has the following technical effects relative to the prior art:

[0016] The application is used for white and black pavement expansion highway construction, the balance beam is arranged at the longitudinal joint between the old cement board and the roller compacted concrete board of the expanded pavement, and the pull rod is arranged at the splicing position of the old cement board and the roller compacted concrete board, so as to ensure the splicing quality of the old road pavement structure and the expanded pavement structure, and avoid longitudinal cracking of the new and old pavements when uneven settlement occurs. The high water permeable concrete belt is arranged to connect the internal drainage systems of the new and old pavement structures with different thicknesses, to drain the internal water of the new and old pavement layers, avoid water damage, and improve the service life of the pavement. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed in the embodiments will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0018] Figure 1 The schematic diagram of the multifunctional splicing structure suitable for the white-on-black pavement reconstruction and expansion of the present application;

[0019] Figure 2 The schematic diagram of the dowel bar planting depth h, the dowel bar planting embedded height H and the dowel bar reserved length L of the present application;

[0020] Figure 3 The relationship curve diagram of the dowel bar planting depth and the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement slab and the roller compacted concrete slab of the present application;

[0021] Figure 4 The relationship curve diagram of the dowel bar embedded height and the cracking force value of the top roller compacted concrete structure layer caused by the dowel bar due to the dowel bar planting of the present application;

[0022] Figure 5 The relationship curve diagram of the dowel bar embedded height and the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement slab and the roller compacted concrete slab of the present application;

[0023] Figure 6 The relationship curve diagram of the dowel bar reserved length and the force value of the dowel bar planted in the old cement slab by the planting method and pulled outwards by the vibration of the roller compacting equipment and the dead load of the present application;

[0024] Figure 7 The simulation schematic diagram of the force value of the dowel bar planted in the old cement slab by the planting method and pulled outwards by the vibration of the roller compacting equipment and the dead load, with the dowel bar planting depth being 20 cm, the dowel bar embedded height being 10 cm and the reserved length being 35 cm of the present application;

[0025] Figure 8 The simulation schematic diagram of the force value of the dowel bar planted in the old cement slab by the planting method and pulled outwards by the vibration of the roller compacting equipment and the dead load, with the dowel bar planting depth being 20 cm, the dowel bar embedded height being 10 cm and the reserved length being 55 cm of the present application;

[0026] Figure 9 The simulation schematic diagram of the force value of the dowel bar planted in the old cement slab by the planting method and pulled outwards by the vibration of the roller compacting equipment and the dead load, with the dowel bar planting depth being 20 cm, the dowel bar embedded height being 10 cm and the reserved length being 85 cm of the present application;

[0027] Figure 10The schematic diagram of the relationship curve between the reserved length of the pull rod and the tensile stress of the asphalt overlay layer bottom surface at the joint position of the old cement board and the roller compacted concrete board of the present application;

[0028] Wherein: 100 - multifunctional splicing structure for white plus black pavement reconstruction and expansion, 1 - balance beam, 2 - high permeable concrete belt, 3 - asphalt overlay layer, 4 - old cement board, 5 - old road water stable base layer, 6 - old road graded gravel cushion layer, 7 - old road subgrade, 8 - expansion asphalt surface layer, 9 - roller compacted concrete board, 10 - water stable lower base layer, 11 - water stable bottom base layer, 12 - expansion road graded gravel cushion layer, 13 - expansion road subgrade, 14 - pull rod, 15 - polyester glass fiber cloth. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0030] The present application aims to provide a multifunctional splicing structure suitable for white plus black pavement reconstruction and expansion, to solve the problems existing in the prior art, to adopt roller compacted concrete board and old cement board splicing, to set a balance beam and a high permeable concrete belt under the new and old road splicing structure, to play multiple functions such as bearing, anti-cracking, anti-deformation, and connected drainage system, and to solve the quality defects such as cracking, deformation, and internal water damage at the splicing position of new and old pavement.

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0032] As Figures 1-10As shown: the embodiment provides a multifunctional splicing structure 100 suitable for white and black pavement reconstruction and expansion, which is used for white and black pavement expansion highway construction, including old road pavement structure, expansion pavement structure, pull rod 14, balance beam 1, high permeable concrete belt 2, the old road pavement structure includes asphalt overlay 3, old cement slab 4, old road water stable base 5 and old road graded gravel cushion 6 arranged from top to bottom, the expansion pavement structure includes expansion asphalt surface layer 8, roller compacted concrete slab 9, water stable lower base 10, water stable bottom base 11 and expansion road graded gravel cushion 12 arranged from top to bottom, the asphalt overlay 3 is connected with the expansion asphalt surface layer 8, the old cement slab 4 is connected with the roller compacted concrete slab 9, one end of the pull rod 14 is located in the old cement slab 4, the other end of the pull rod 14 is located in the roller compacted concrete slab 9, the balance beam 1 is located at the bottom of the joint of the old cement slab 4 and the roller compacted concrete slab 9, and the balance beam 1 is located between the old road water stable base 5, the old road graded gravel cushion 6, the water stable lower base 10 and the water stable bottom base 11, the high permeable concrete belt 2 is arranged at the bottom of the balance beam 1, the high permeable concrete belt 2 is located between the old road graded gravel cushion 6, the water stable bottom base 11 and the expansion road graded gravel cushion 12, the high permeable concrete belt 2 connects the old road graded gravel cushion 6 and the expansion road graded gravel cushion 12, and the balance beam 1 and the high permeable concrete belt 2 can act as the side formwork for the construction of the water stable lower base 10 and the water stable bottom base 11 of the expansion pavement structure. The embodiment sets the balance beam 1 at the bottom of the longitudinal joint of the old cement slab 4 and the expansion pavement roller compacted concrete slab 9, and sets the pull rod 14 at the splicing position of the old cement slab 4 and the roller compacted concrete slab 9, so as to ensure the splicing quality of the old road pavement structure and the expansion pavement structure, and avoid longitudinal cracking of the new and old pavements when they are unevenly settled. By setting the high permeable concrete belt 2, the internal drainage systems of the new and old pavement structures with different thicknesses are connected, the internal water between the new and old pavement layers is drained, water damage is avoided, and the service life of the pavement is improved.

[0033] Specifically, in the embodiment, the slotting is performed by using a modified mine milling and digging machine, and the horizontal depth and vertical height of milling and digging are freely adjusted according to the size of the balance beam 1 and the high permeable concrete belt 2 embedded in the old cement slab 4, so as to solve the problems of slow construction progress and high construction cost. The old road water stable base 5 and the old road graded gravel cushion 6 are excavated to form a recessed space, and one side of the balance beam 1 and the high permeable concrete belt 2 is arranged in the recessed space.

[0034] In the embodiment, the thicknesses of the asphalt overlay 3 and the extended asphalt surface layer 8 are the same, and the upper surfaces of the asphalt overlay 3 and the extended asphalt surface layer 8 are arranged flush; the thicknesses of the old cement slab 4 and the roller compacted concrete slab 9 are the same, and the upper surfaces of the old cement slab 4 and the roller compacted concrete slab 9 are arranged flush, the flexural tensile strength of the roller compacted concrete slab 9 is not less than 3.5 MPa, and the 7-day unconfined compressive strength of the roller compacted concrete slab 9 is not less than 10 MPa; the joints between the asphalt overlay 3 and the extended asphalt surface layer 8 are arranged staggered with the joints between the old cement slab 4 and the roller compacted concrete slab 9.

[0035] In the embodiment, before the construction of the extended asphalt surface layer 8, the self-adhesive polyester fiberglass cloth 15 is pasted along the top surface of the joint between the old cement slab 4 and the roller compacted concrete slab 9, and the width of the polyester fiberglass cloth 15 located on the old cement slab 4 is the same as the width of the polyester fiberglass cloth 15 located on the roller compacted concrete slab 9.

[0036] In the embodiment, one side of the balanced beam 1 is connected with the old road stabilized base 5 and the old road graded gravel cushion layer 6, and the other side of the balanced beam 1 is connected with the stabilized lower base 10 and the stabilized bottom base 11, and the upper surfaces of the balanced beam 1, the old road stabilized base 5 and the stabilized lower base 10 are arranged flush.

[0037] In the embodiment, the thickness of the balanced beam 1 is the sum of the thickness of the old road stabilized base 5 and the thickness of one of the old road graded gravel cushion layers 6; the balanced beam 1 is a concrete structure, and the concrete composition of the balanced beam 1 preferably comprises, in mass parts, 360-400 parts of Portland cement, 737-757 parts of sand, 1101-1141 parts of stone, 132-172 parts of water and 3.5-4.1 parts of water reducing agent. The Portland cement is preferably P042.5 ordinary Portland cement; the sand is preferably natural river sand, and the fineness modulus of the sand is 2.5-2.9; the stone is preferably 5-20 mm particle size stone, and more preferably a mixture of 5-10 mm particle size stone and 10-20 mm particle size stone, and the mass ratio of the 5-10 mm particle size stone to the 10-20 mm particle size stone in the mixture is preferably 3:7. The water reducing agent is preferably HJ-HPC polycarboxylic acid high performance water reducing agent. The measured slump of the balanced beam 1 is preferably 175-180 mm, the measured bulk density is preferably 2400, and the 7d and 28d compressive strengths are preferably 48.9-52.8 MPa and 60.3-61.7 MPa, respectively.

[0038] In this embodiment, the thickness of the high water permeable concrete strip 2 is the sum of two-thirds of the thickness of the old road graded gravel cushion 6, the distance between the lower surface of the old road graded gravel cushion 6 and the upper surface of the expanded road graded gravel cushion 12, and two-thirds of the thickness of the expanded road graded gravel cushion 12; the compressive strength of the high water permeable concrete strip 2 is not less than 10 MPa; the porosity of the high water permeable concrete strip 2 is not less than 20%; and the concrete composition of the high water permeable concrete strip 2 preferably includes 381-401 parts of Portland cement, 1530-1590 parts of stone, and 119-139 parts of water. The Portland cement is preferably P042.5 ordinary Portland cement; the particle size of the stone is preferably 5-10 mm; and the measured bulk density of the high water permeable concrete strip 2 is preferably 2080, and the 7d and 28d compressive strengths are preferably 13.2-14.2 MPa and 17.3-25.2 MPa.

[0039] In this embodiment, a plurality of pull rods 14 holes are arranged at equal intervals along the longitudinal direction of the old cement slab 4 in the old cement slab 4, the pull rod 14 holes are injected with anchoring glue, one end of each pull rod 14 extends into a pull rod 14 hole, and the other end of each pull rod 14 is fixed in the roller compacted concrete slab 9 during construction of the roller compacted concrete slab 9.

[0040] The difference between the present application and the prior art is that, in the prior art, a pull rod is arranged in the construction of a pavement structure, the pull rod is implanted in an old cement pavement, and the pull rod reserved end is poured with freshly mixed cement concrete to form a state in which the pull rod is horizontally arranged in the new and old cement concrete pavement structure; the feature of the present embodiment is that the pavement structure of the pull rod 14 reserved end is a roller compacted concrete pavement structure, loose granular gravel with different particle sizes of 0-30 mm is laid on the pull rod 14 using paving equipment, and the roller compacted concrete pavement structure is compacted using a road roller, and therefore the technical problem faced by the present embodiment is that there is a risk that the pull rod 14 will be pulled out of the old cement slab 4 horizontally during the compaction process. Therefore, the anchoring glue strength of the pull rod 14 and the tensile strength control standard after anchoring need to be accurately determined. A finite element analysis method is used to simulate the actual construction conditions to determine the same.

[0041] In the finite element analysis, the pavement structure, the pull rod 14, and the load are as follows:

[0042]

[0043]

[0044]

[0045] The thickness parameters of the old road pavement structure and the pavement structure of the extension are determined by drilling cores, and the modulus parameters of the old road pavement structure and the pavement structure of the extension are determined by indoor dynamic modulus test of drilling cores (board body material) or are obtained by inverse calculation according to the pavement field modulus (loose granular material); the modulus of the loose state of the roller compacted concrete is predicted to be 500-1000 MPa.

[0046] The double circular uniform load has a load size of 0.7 MPa; the load only acts on the surface of the roller compacted concrete, and the load edge is close to the joint of the roller compacted concrete slab 9 and the old cement slab 4.

[0047] By changing the depth of the anchor rod 14 (the depth of the anchor rod 14 extending into the old cement slab 4) h, the embedded height of the anchor rod 14 (the height of the anchor rod 14 from the bottom of the old cement slab 4) H and the reserved length of the anchor rod 14 (the length of the anchor rod 14 exposed outside after anchoring, that is, the length of the anchor rod 14 in the roller compacted concrete slab 9) L:

[0048] ①Calculate the force value of the anchor rod 14 set in the old cement slab 4 by anchoring, which is pulled outwards by the vibration and self-weight load of the roller compacted construction;

[0049] ②Calculate the force value of the splitting failure of the roller compacted concrete slab 9 caused by the stress concentration at the position in contact with the anchor rod 14 due to the setting of the anchor rod 14 in the roller compacted concrete structure;

[0050] ③Calculate the tensile stress value of the bottom surface of the asphalt overlay corresponding to the joint position of the old cement slab 4 and the roller compacted concrete slab 9.

[0051] Calculation process:

[0052] The open-source commercial ABAQUS finite element analysis software is used for calculation, and the basic steps include:

[0053] 1) Modeling (drawing a plane strain model according to the structural layer of the old road pavement structure and the pavement structure of the extension, and the thickness of each layer);

[0054] 2) Material parameter setting (see the table above for specific parameters);

[0055] 3) Load and boundary condition setting (load parameters are shown in the table above, and boundary conditions are that the bottom is limited in all degrees of freedom, left and right are limited in horizontal and rotational degrees of freedom);

[0056] 4) Mesh division (mesh division is performed by structure division, and the mesh density is set to 28);

[0057] 5) Software automatic calculation;

[0058] 6) Extract the calculation result values of the key positions ①②③.

[0059] The calculation results and analysis are as follows:

[0060] (1) The anchoring depth h of the tie rod 14: (single factor analysis, assuming that the tie rod 14 is arranged at 1 / 2 of the thickness of the old cement board 4, and the reserved length of the tie rod 14 is equal to the anchoring depth).

[0061]

[0062]

[0063] It can be seen that the anchoring of the tie rod 14 can effectively reduce the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement board 4 and the roller compacted concrete board 9. However, with the increase of the anchoring depth of the tie rod 14, the reduction effect gradually tends to be flat. When the anchoring depth is 20 cm, the cost performance is the highest (the greater the anchoring depth, the more the amount of steel and anchoring glue, and the higher the anchoring process cost).

[0064] (2) The embedded height H of the tie rod 14: (single factor analysis, assuming that the reserved length of the tie rod 14 is equal to the anchoring depth equal to 20 cm determined in (1)).

[0065]

[0066]

[0067] It can be seen that the increase of the embedded height of the tie rod 14 will increase the stress concentration of the roller compacted concrete board 9 and the cracking force value of the roller compacted concrete board 9 at the top of the tie rod 14 caused by the arrangement of the tie rod 14. When the embedded height of the tie rod 14 is less than 12 cm, the cracking force value is at a low level, and when the embedded height exceeds 13 cm, the force value increases rapidly. Therefore, it is reasonable to set the embedded height of the tie rod 14 to be less than or equal to 12 cm.

[0068] The increase of the embedded height of the tie rod 14 will effectively reduce the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement board 4 and the roller compacted concrete board 9. When the embedded height of the tie rod 14 is greater than 10 cm, the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement board 4 and the roller compacted concrete board 9 tends to be flat, and as the embedded height approaches the thickness of the old cement board 4, the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement board 4 and the roller compacted concrete board 9 tends to rise slightly, but not significantly.

[0069] In order to ensure that the tensile stress of the asphalt overlay bottom surface at the joint position of the old cement board 4 and the roller compacted concrete board 9 is at a low level, the embedded height of the tie rod 14 should be greater than 10 cm.

[0070] In summary, the embedded height of the tie rod 14 is 10-12 cm.

[0071] (3) Reserved length L: (single factor analysis, assuming conditions: the dowel bar 14 anchorage depth is equal to 20 cm determined in (1), and the dowel bar 14 embedment is equal to 10 cm determined in (2))

[0072]

[0073]

[0074] As shown in Figures 7-9 , the force value of point A is 4.103 MPa, the force value of point B is 4.856 MPa, and the force value of point C is 5.375 MPa.

[0075] Analysis shows that as the reserved length increases, the vibration of the rolling equipment and the dead load make the force value of the dowel bar 14 set in the old cement board 4 by anchoring outwardly become larger and larger, and when it reaches 60 cm, it will enter a period of slow growth, and when it exceeds 80 cm, it will enter a stage of rapid growth.

[0076]

[0077]

[0078] Analysis shows that as the reserved length increases, the tensile stress of the asphalt overlay at the joint position of the old cement board 4 and the roller compacted concrete slab 9 decreases, and when the reserved length exceeds 20 cm, the reduction speed slows down, but the asphalt overlay is still in tension and has a risk of cracking. When the reserved length reaches 50 cm, the tensile stress of the asphalt overlay at the joint position of the old cement board 4 and the roller compacted concrete slab 9 is 0, and the asphalt overlay is still in compression and has no risk of cracking. Therefore, the reserved length needs to be controlled above 50 cm, and in combination with the change rule of the force value of the dowel bar 14 set in the old cement board 4 by anchoring outwardly due to the vibration of the rolling equipment and the dead load, the reserved length range is 50-60 cm.

[0079] When the reserved length is 50-60 cm, the force value of the dowel bar 14 set in the old cement board 4 by anchoring outwardly due to the vibration of the rolling equipment and the dead load should be controlled within 4.7-5.1 MPa (1 MPa = 10 6 N / m 2 ) (see the above table data).

[0080] The diameter D of the dowel bar 14 is 16 mm, and the anchorage depth is 20 cm, so the tensile area of the dowel bar 14 is:

[0081] S = π × D × h = π × (16 / 1000) × (20 / 100) = 0.01 m 2

[0082] The tensile force that the anchorage rod 14 can be subjected to during the rolling construction is:

[0083] F min = 4.7 x 106N / m 2 x 0.01 m 2 = 47000 N = 47 kN

[0084] F max = 5.1 x 106N / m 2 x 0.01 m 2 = 51000 N = 51 kN

[0085] In terms of the quality indicators of the anchorage adhesive, the breaking shear force of the anchorage adhesive should be controlled to be not less than 51 kN.

[0086] In summary, in the embodiment, the depth of the anchorage rod 14 extending into the old cement board 4 is 20 cm, the height of the anchorage rod 14 from the bottom of the old cement board 4 is 10-12 cm, and the length of the anchorage rod 14 reserved in the rolled concrete slab 9 is 50-60 cm.

[0087] The embodiment adopts the splicing of the rolled concrete and the old cement board 4, reduces the difference in the deformation modulus of the new and old pavement base structures, and avoids the cracking of the pavement caused by the deformation of the internal structure of the new and old pavements after splicing.

[0088] In the embodiment, the old road base 7 is located below the old road graded gravel cushion 6, the expanded road base 13 is located below the expanded road graded gravel cushion 12, the old road base 7 and the expanded road base 13 are connected, the high-pervious concrete belt 2 is connected with the old road base 7, and the high-pervious concrete belt 2 is located on the top surface of the joint between the old road base 7 and the expanded road base 13.

[0089] In the embodiment, the pavement structure below the rolled concrete slab 9 of the expanded pavement structure is inconsistent with the old road pavement structure, and the combination and thickness can be set according to the current pavement structure standard.

[0090] The principles and implementation manners of the present application are described in the specific examples in the specification, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the present application. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A multi-functional splicing structure suitable for the reconstruction and expansion of asphalt-white roads, characterized in that: The old road pavement structure includes asphalt overlay, old cement slab, old road water stable base layer and old road graded gravel cushion layer arranged from top to bottom, the extension pavement structure includes extension asphalt surface layer, rolled compact concrete slab, water stable lower base layer, water stable bottom base layer and extension road graded gravel cushion layer arranged from top to bottom, the asphalt overlay is connected with the extension asphalt surface layer, the old cement slab is connected with the rolled compact concrete slab, one end of the tie rod is located in the old cement slab, the other end of the tie rod is located in the rolled compact concrete slab, the balance beam is located at the bottom of the joint of the old cement slab and the rolled compact concrete slab, and the balance beam is located between the old road water stable base layer, the old road graded gravel cushion layer, the water stable lower base layer and the water stable bottom base layer, the high water permeable concrete belt is arranged at the bottom of the balance beam, and the high water permeable concrete belt is located between the old road graded gravel cushion layer, the water stable bottom base layer and the extension road graded gravel cushion layer; the high water permeable concrete belt connects the old road graded gravel cushion layer and the extension road graded gravel cushion layer; The depth of the tie rod extending into the old cement slab is 20 cm, the height of the tie rod from the bottom of the old cement slab is 10-12 cm, and the length of the tie rod in the rolled compact concrete slab is 50-60 cm.

2. The multifunctional splicing structure suitable for white- on-black pavement reconstruction and expansion according to claim 1, characterized in that: The thickness of the asphalt overlay and the extension asphalt surface layer is the same, and the upper surfaces of the asphalt overlay and the extension asphalt surface layer are arranged flush; the thickness of the old cement slab and the rolled compact concrete slab is the same, and the upper surfaces of the old cement slab and the rolled compact concrete slab are arranged flush; the joint between the asphalt overlay and the extension asphalt surface layer is arranged in a staggered manner with the joint between the old cement slab and the rolled compact concrete slab.

3. The multifunctional splicing structure suitable for white- on-black pavement reconstruction and expansion according to claim 2, characterized in that: The top surface of the joint between the old cement slab and the rolled compact concrete slab is provided with a polyester glass cloth, and the width of the polyester glass cloth located in the old cement slab is the same as the width of the polyester glass cloth located in the rolled compact concrete slab.

4. The multifunctional splicing structure suitable for whitetopping reconstruction and expansion according to claim 1, characterized in that: One side of the balance beam is connected with the old road water stable base layer and the old road graded gravel cushion layer, the other side of the balance beam is connected with the water stable lower base layer and the water stable bottom base layer, and the upper surfaces of the balance beam, the old road water stable base layer and the water stable lower base layer are arranged flush.

5. The multifunctional splicing structure suitable for white-topping pavement reconstruction and expansion according to claim 1, characterized in that: The balance beam is a concrete structure, and the thickness of the balance beam is the sum of the thickness of the old road water stable base layer and one-third of the thickness of the old road graded gravel cushion layer.

6. The multifunctional splicing structure suitable for white-topping pavement reconstruction and expansion according to claim 1, characterized in that: The thickness of the high water permeable concrete belt is the sum of two-thirds of the thickness of the old road graded gravel cushion layer, the distance between the lower surface of the old road graded gravel cushion layer and the upper surface of the extension road graded gravel cushion layer, and two-thirds of the thickness of the extension road graded gravel cushion layer; the compressive strength of the high water permeable concrete belt is not less than 10 MPa; and the porosity of the high water permeable concrete belt is not less than 20%.

7. The multifunctional splicing structure suitable for white-topping pavement reconstruction and expansion according to claim 1, characterized in that: The old cement plate is provided with a plurality of pull rod holes at equal intervals along the longitudinal direction of the old cement plate, the pull rod holes are provided with anchoring glue, the breaking shear force of the anchoring glue is not less than 51kN, and one end of each pull rod extends into one pull rod hole.

8. The multifunctional splicing structure suitable for white-topping pavement reconstruction and expansion according to claim 1, characterized in that: In the construction of the roller compacted concrete plate, the force for pulling out the pull rod in the old cement plate is 4.7-5.1MPa. 9.The multifunctional splicing structure suitable for white-topping pavement reconstruction and expansion according to claim 1, characterized in that: The old road subgrade is located below the old road graded gravel cushion, the expanded road subgrade is located below the expanded road graded gravel cushion, the old road subgrade and the expanded road subgrade are connected, the high water permeable concrete belt is connected with the old road subgrade, and the high water permeable concrete belt is located on the top surface of the joint between the old road subgrade and the expanded road subgrade.

10. The multifunctional splicing structure suitable for whitetopping reconstruction and expansion according to claim 1, characterized in that: The concrete composition of the balanced beam includes 360-400 parts of Portland cement, 737-757 parts of sand, 1101-1141 parts of stone, 132-172 parts of water and 3.5-4.1 parts of water reducing agent in terms of mass fraction; and the concrete composition of the high water permeable concrete belt includes 381-401 parts of Portland cement, 1530-1590 parts of stone and 119-139 parts of water.

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