CN111576127B - Highway engineering new and old pavement splicing structure and construction method thereof - Google Patents

Abstract

The invention discloses a splicing structure of new and old road surfaces in highway engineering and a construction method thereof, belonging to the field of highway reconstruction and expansion engineering, wherein the splicing structure of the new and old road surfaces comprises an original road surface and a new road surface, the new road surface sequentially comprises a cushion layer, a subbase layer, a base layer, a lower layer, a middle layer and an upper layer from bottom to top, and the upper layer is paved on the top of the middle layer and the original road surface; the splicing position of the cushion layer and the subbase layer with the original road surface is provided with a sand-free macroporous concrete drainage belt, and the splicing position of the base layer with the original road surface is provided with a cast-in-situ concrete layer; and steel bars and reinforcing members are arranged between the cast-in-situ concrete layer and the original pavement. The construction method of the splicing structure of the new road surface and the old road surface comprises the following steps: s1, measuring and lofting; s2, milling an old road; s3, excavating steps; s4, constructing a cushion layer and a subbase layer; s5, constructing a base layer; s6, asphalt pavement construction, deformation and uneven settlement at the splicing position of the new pavement and the old pavement are reduced, quality common problems of longitudinal reflection cracks on the pavement are reduced, and the service life of the pavement is prolonged.

Description

Highway engineering new and old pavement splicing structure and construction method thereof

Technical Field

The invention relates to the field of highway reconstruction and expansion engineering, in particular to a splicing structure of new and old road surfaces in highway engineering and a construction method thereof.

Background

Along with the rapid development of traffic industry in China, the traffic flow of expressways and municipal roads is increased year by year, a lot of roads do not reach the service life, the traffic flow is saturated or tends to be saturated, the improvement measures faced by saturated roads are basically two, namely, the construction of a restoration line is carried out, and the expansion and widening are carried out on the basis of the original roads. The highway extension and widening has the advantages of less investment and land saving, and is preferentially adopted under the conditions of geology, environment and the like. The splicing effect of new and old roads in the road reconstruction and expansion project directly influences the construction quality of the roads and the service life of the roads, and how to effectively splice the new and old roads and reduce the occurrence of road surface diseases at the splice position is always a difficult point of reconstruction and expansion engineering construction and is also one of key technologies.

In the prior road surface splicing and widening process, uneven settlement exists, and reflection cracks appear on an asphalt surface layer, so the invention provides a new and old road surface splicing structure for highway engineering and a construction method thereof.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention aims to provide a splicing structure of new and old road surfaces in highway engineering and a construction method thereof.

In order to achieve the above purpose, the present invention provides the following technical solutions:

The new and old pavement splicing structure for the highway engineering comprises an original pavement and a new pavement, wherein a step is arranged on one side, close to the new pavement, of the original pavement, the new pavement sequentially comprises a cushion layer, a base layer, a lower layer, a middle surface layer and an upper layer from bottom to top, and the upper layer is paved on the top of the middle surface layer and the top of the original pavement;

The foundation layer and the subbase layer are provided with a sand-free macroporous concrete drainage belt at the joint with the original road surface, the sand-free macroporous concrete drainage belt is paved by sand-free macroporous concrete, the base layer is provided with a cast-in-situ concrete layer at the joint with the original road surface, and the cast-in-situ concrete layer is formed by casting C40 cement on site;

and steel bars and reinforcing members are arranged between the cast-in-situ concrete layer and the original pavement.

Further preferred are: the reinforcement comprises prefabricated reinforced concrete, an insert block and a strong spring;

The prefabricated reinforced concrete is supported above the subbase layer and is close to the splicing position of the new road surface and the original road surface, a first slot is formed in the prefabricated reinforced concrete, a second slot is formed in the step transversely spliced by the original road surface, two inserting blocks are arranged, one inserting block is inserted into the first slot, and the other inserting block is inserted into the second slot;

the strong spring is fixed between the two inserting blocks.

Further preferred are: the depth of the first slot and the depth of the second slot are both larger than the height of the insert block, so that the insert block is positioned below the step formed by transversely splicing the original road surface.

Further preferred are: the second slots are arranged in a plurality along the longitudinal direction of the original pavement, the precast reinforced concrete is arranged in a plurality along the longitudinal direction of the original pavement, and each second slot corresponds to one precast reinforced concrete;

One end of the prefabricated reinforced concrete is fixed with a dovetail block, the other end of the prefabricated reinforced concrete is provided with a dovetail groove matched with the dovetail block on the adjacent prefabricated reinforced concrete, and the adjacent prefabricated reinforced concrete is spliced with the dovetail groove through the dovetail block.

Further preferred are: the steel bars are horizontally arranged, one end of each steel bar is fixed in the original pavement, the other end of each steel bar is fixed in the cast-in-place concrete layer, and one steel bar is arranged every 0.3m in the longitudinal direction of the original pavement.

Further preferred are: a first glass fiber grille is laid at the bottom of the lower surface layer and is positioned at the joint of the middle surface layer and the original road surface;

The second glass fiber grille is arranged at the bottom of the middle surface layer, is positioned on the step formed by transversely splicing the bottom of the middle surface layer and the original road surface and is close to the splicing position of the original road surface and the new road surface;

The bottom of the lower layer is provided with a third glass fiber grid, and the third glass fiber grid is positioned on the step formed by transversely splicing the bottom of the lower layer and the original road surface and is close to the splicing position of the original road surface and the new road surface.

Further preferred are: the step of the horizontal concatenation of former road surface below is provided with geogrid, geogrid is located no sand macroporous concrete drainage strip with the bed course below.

A construction method of a splicing structure of new and old road surfaces in highway engineering comprises the following steps:

S1, measuring and lofting: setting out the splice seam position of the pavement, setting out the plane position of the pavement cushion layer and the sand-free macroporous concrete drainage belt on the pavement bed;

S2, milling an old road: digging out a cement board and an asphalt layer additionally paved on the top of the cement board within the range of the original hard shoulder, and cutting off an old cement concrete panel with the thickness of the original hard shoulder not less than 0.35 m;

s3, step excavation: step excavation is carried out on the old road at the joint so that each structural layer of the original road surface is provided with steps, and the width of each step which is transversely spliced is 35cm; digging a second slot on the step for being matched and connected with the prefabricated reinforced concrete;

S4, cushion layer and subbase layer construction: firstly paving a soil engineering grid, paving sand-free macroporous concrete, compacting by using a flat plate rammer, paving a cushion layer and a base layer before final setting of the sand-free macroporous concrete, simultaneously rolling and forming the cushion layer and the base layer with the sand-free macroporous concrete, and simultaneously maintaining; then splicing prefabricated reinforced concrete, and respectively inserting the insertion blocks at two ends of the strong spring into the first slot and the second slot;

S5, base layer construction: firstly, planting ribs, pouring C40 concrete to form a cast-in-situ concrete layer, paving a base layer, and compacting by vibrating through a small flat plate vibrator;

S6, asphalt surface layer construction: firstly paving a third glass fiber grating, paving a lower layer, paving a second glass fiber grating and a middle layer after rolling and forming, then rolling, finally paving a first glass fiber grating at the joint of the original pavement and the middle layer, and then performing full-section upper layer construction.

Further preferred are: when the reinforcing steel bar is planted, holes are drilled firstly, and then reinforcing steel bars with the diameter of 25 and the length of 1.0m are buried in the original road surface, wherein the buried depth is 0.5m.

Further preferred are: before the bar planting starts, positioning and paying off are firstly carried out, a drilling part is drawn by using a color chalk, drilling is carried out by using an electric hammer, drilling is stopped when the drilling depth is reached, and drilling depth and drilling diameter are measured;

After drilling holes into a batch, cleaning holes one by one, and when cleaning holes by using compressed air, firstly stretching a nozzle into the bottom of the holes, blowing clean oil-free compressed air, pulling out the nozzle outwards, and repeating for three times; inserting the bristle brush into the hole, and brushing three times in a reciprocating way; then the nozzle stretches into the bottom of the hole to blow air, the nozzle is pulled out, and the process is repeated for three times;

Before the bar planting, acetone or industrial alcohol is used for wiping the hole wall and the hole bottom.

In summary, the invention has the following beneficial effects:

1. Simple and practical

The construction method adopts construction materials and mechanical equipment for common use in construction sites, and has the characteristics of simple and convenient operation, strong applicability, simple and convenient material obtaining and the like.

2. Unique internal drainage structure

The sand-free macroporous concrete drainage belt is arranged at the bottommost layer of the splicing position of the new road surface and the old road surface, and the characteristics of high proportion and high porosity of the sand-free macroporous concrete coarse aggregate are utilized, so that water seepage in the original road surface structure can be effectively discharged from the central separation belt water collecting well through the longitudinal drainage of the sand-free macroporous concrete drainage belt along the road, and the phenomena of bearing capacity reduction, uneven sedimentation and the like caused by water seepage of the road surface structure layer can be effectively reduced.

3. Step-shaped pavement structure layer lap joint mode

The asphalt pavement milling and hard road shoulder cutting mode is adopted, the splicing parts of the new and old pavement are in a step shape according to the original pavement structure layer composition, the splicing parts of the new and old pavement are in staggered lap joint, and the stress state of the pavement structure layer at the lap joint part is strengthened.

4. Reasonable stress transmission and digestion mode

The side edge of the original pavement concrete panel is drilled and provided with the pull rod (reinforcing steel bars), the prefabricated reinforced concrete and the strong spring, and vertical and transverse stresses generated by the original pavement vehicle load are transmitted to a new pavement through the pull rod and the strong spring, so that the stress concentration phenomenon of the side edge of the original pavement structure is greatly reduced, and the service life of the original pavement structure layer is prolonged.

Drawings

FIG. 1 is a block flow diagram of an embodiment, which is mainly used for embodying a construction method of a splicing structure of new and old pavements;

fig. 2 is a schematic structural diagram of an embodiment, which is mainly used for embodying a splicing structure of new and old pavements;

FIG. 3 is a schematic structural view of an embodiment, primarily for embodying the mounting structure of the stiffener;

fig. 4 is a schematic cross-sectional view of an embodiment, primarily for embodying a specific structure of the stiffener.

In the figure, 1, an original road surface; 21. a cushion layer; 22. a base layer; 23. a base layer; 24. an underlying layer; 25. a middle surface layer; 26. an upper layer; 3. a first glass fiber grid; 4. a second fiberglass grill; 5. a third fiberglass grill; 6. reinforcing steel bars; 7. a cast-in-situ concrete layer; 8. sand-free macroporous concrete drainage belt; 9. a reinforcing member; 91. prefabricating reinforced concrete; 92. dovetail blocks; 93. a dovetail groove; 94. inserting blocks; 95. a strong spring; 96. a first slot; 97. a second slot; 10. geogrid.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Examples: the utility model provides a new and old road surface mosaic structure of highway engineering, as shown in fig. 2-4, includes original road surface 1 and new road surface. The original road surface 1 is provided with steps on one side close to the new road surface, the steps are provided with a plurality of steps, and the width of the transverse splicing steps is 35cm. The new road surface sequentially comprises a cushion layer 21, a bottom base layer 22, a base layer 23, a lower layer 24, a middle layer 25 and an upper layer 26 from bottom to top, wherein the upper layer 26 is paved on top of the middle layer 25 and the original road surface 1. The lower layer 24, the middle layer 25 and the upper layer 26 are all asphalt layers, and the base layer 23 is a cement stabilized macadam base layer. The cushion layer 21 and the subbase layer 22 are provided with a sand-free macroporous concrete drainage belt 8 at the joint with the original road surface 1, and the sand-free macroporous concrete drainage belt 8 is paved by sand-free macroporous concrete. The width of the sand-free macroporous concrete drainage belt 8 is 0.5m. The base layer 23 is provided with a cast-in-situ concrete layer 7 at the joint with the original pavement 1, and the cast-in-situ concrete layer 7 is formed by casting C40 cement on site.

In the technical scheme, the sand-free macroporous concrete drainage belt 8 is arranged at the bottommost layer of the splicing position of the new road surface and the old road surface, and the characteristics of high proportion and high porosity of the sand-free macroporous concrete coarse aggregate are utilized, so that water seepage in the original road surface 1 structure can be effectively discharged from the central separation belt water collecting well through the longitudinal drainage of the sand-free macroporous concrete drainage belt 8 along the road, and the phenomena of bearing capacity reduction, uneven sedimentation and the like caused by water seepage of the road surface structural layer can be effectively reduced. The step design of the splicing parts of the new and old roads ensures that the splicing parts of the new and old roads are overlapped in an interlaced way, and the stress state of the road surface structural layer at the overlapped part is enhanced.

Referring to fig. 2 to 4, steel bars 6 and reinforcing members 9 are provided between the cast-in-place concrete layer 7 and the original pavement 1. The steel bars 6 are horizontally arranged, one end of each steel bar is fixed in the original pavement 1, the other end of each steel bar is fixed in the cast-in-situ concrete layer 7, and the steel bars 6 are arranged every 0.3m in the longitudinal direction of the original pavement 1. The insertion depth of the reinforcing bars 6 in the original road surface 1 is the same as that in the new road surface, and is 0.5m.

Referring to fig. 2-4, the reinforcement 9 includes precast reinforced concrete 91, an insert 94, and a strong spring 95. The prefabricated reinforced concrete 91 is supported above the subbase layer 22 and is close to the joint of the new road surface and the original road surface 1, and a first slot 96 is formed in the prefabricated reinforced concrete 91. The step of the horizontal concatenation of former road surface 1 has seted up second slot 97, and the inserted block 94 is provided with two, and one of them inserted block 94 and first slot 96 looks adaptation just insert and establish in first slot 96, and another inserted block 94 and second slot 97 looks adaptation just insert and establish in second slot 97. The first slot 96 and the second slot 97 are both T-shaped slots. A strong spring 95 is secured between the two inserts 94. In order to firmly connect the cast-in-situ concrete layer 7 and the original pavement 1 together during the casting of the C40 cement in situ, specifically, the depth of the first slot 96 and the second slot 97 is greater than the height of the insert 94, so that the insert 94 is positioned below the step where the original pavement 1 is transversely spliced. As such, when the C40 cement is poured in place, the C40 cement will fill the first and second slots 96, 97 above the insert 94. The precast reinforced concrete 91 is buried in the cast-in-situ concrete layer 7 and is not in contact with the sub-base layer 22.

Referring to fig. 2 to 4, the precast reinforced concrete 91 is located under the reinforcing steel bars 6, a plurality of second insertion grooves 97 are provided along the longitudinal direction of the original pavement 1, and a plurality of precast reinforced concrete 91 are arranged along the longitudinal direction of the original pavement 1, and each second insertion groove 97 corresponds to one precast reinforced concrete 91. One end of the prefabricated reinforced concrete 91 is fixed with a dovetail block 92, the other end is provided with a dovetail groove 93 which is matched with the dovetail block 92 on the adjacent prefabricated reinforced concrete 91, and the adjacent prefabricated reinforced concrete 91 is spliced with the dovetail groove 93 through the dovetail block 92.

In the above technical solution, when the C40 cement is cast in place, the C40 cement is filled into the first slot 96 and the second slot 97 above the insert 94, so that the original road surface 1 and the new road surface are tightly lapped together by the reinforcing steel bars 6, the precast reinforced concrete 91 and the strong springs 95. The purpose of the steel bar 6 and the strong spring 95 is to strengthen the whole strength between the original road surface 1 and the new road surface, however, the steel bar 6 belongs to a rigid piece, once deformed, the steel bar cannot be recovered, and once deformed, the pulling resistance and the bearing capacity are greatly weakened. Therefore, in order to improve the service life and the driving safety of the highway, the invention adds the strong spring 95 on the basis of the pull rod, thereby not only preventing the crack at the splicing position, but also preventing the crack at the splicing position from further widening after the crack is generated, and greatly improving the driving safety of the highway.

Referring to fig. 2 to 4, in order to improve the road surface stability, it is preferable that the first glass fiber grid 3 is laid at the bottom of the lower surface layer 24, and the first glass fiber grid 3 is located at the junction of the middle surface layer 25 and the original road surface 1. The second glass fiber grille 4 is arranged at the bottom of the middle surface layer 25, and the second glass fiber grille 4 is positioned on a step where the bottom of the middle surface layer 25 and the original road surface 1are transversely spliced and is close to the splice of the original road surface 1 and the new road surface. The third glass fiber grille 5 is arranged at the bottom of the lower layer 24, and the third glass fiber grille 5 is positioned on a step where the bottom of the lower layer 24 and the original road surface 1are transversely spliced and is close to the splice of the original road surface 1 and the new road surface. The geogrid 10 is arranged on the step of the transverse splicing at the lowest part of the original pavement 1, and the geogrid 10 is positioned below the sand-free macroporous concrete drainage belt 8 and the cushion layer 21.

The construction method of the splicing structure of the new road surface and the old road surface, as shown in fig. 1, comprises the following steps:

S1, measuring and lofting

1. The central position, elevation, cross section, side slope, and flat curve superelevation of the route all have to meet the requirements of the design drawing and the instructions of the supervision engineer.

2. And lofting out the splice seam position of the pavement, wherein the splice seam position is positioned in the 3 rd lane, and the distance between the edge of the old concrete panel and the boundary line of the 3 rd lane and the 4 th lane is 1.35m.

3. And (3) carrying out lofting according to the position of the splicing line in the section of the design drawing by line center control, pushing out the heights of each step surface and each layer of the road surface according to the gradient of the transverse slope of the road, and lofting the plane positions of the road surface cushion layer 21 and the cast-in-situ sand-free macroporous concrete on the road bed.

S2, milling and planing old road

Before the pavement splicing construction, firstly, the cement board and the asphalt layer at the top in the range of the original hard road shoulder are removed, and the old cement concrete panel with the original hard road shoulder not smaller than 0.35m is removed. If the hard shoulder has post-cast strip concrete, the post-cast strip needs to be completely cut off. The cement board is directly excavated from the pouring construction joint of the original road shoulder concrete slab by adopting an excavator, and the foundation layer 23 and the subbase layer 22 of the original road are prevented from being disturbed during the excavation. The asphalt is excavated by adopting a milling method, the asphalt in the range of the original pavement 1 to be excavated is firstly lofted during milling, the white ash is sprayed for marking, and the cutting excavation is adopted in the range of 10cm left during milling, so that the joint surface of the cutting seam and the asphalt of the new pavement is straight and smooth.

S3, step excavation

As the original road surface 1 is operated for many years, the roadbed settlement is basically completed, and the differential settlement of the new roadbed and the old roadbed is reduced to reduce the settlement of the new roadbed and the old roadbed, thereby reducing the probability of longitudinal cracks of the new roadbed and the old roadbed, and the roadbed is widened by adopting a step digging mode.

In order to prevent the reflection cracks from happening to the road surface too early due to the fact that the road surface splice joint penetrates from top to bottom, the step width of the new road surface and the old road surface needs to be set to be wider, and the width of the transverse splice step is 35cm wide.

When the steps are excavated, the mechanical cooperation is adopted for manual excavation, and after the mechanical excavation, the manual repair is adopted for preventing the overexcavation, so that the steps are required to be compact on the surfaces and loose objects are avoided. During excavation, the line shape of an excavation surface and the width of a step are guaranteed, and the vertical excavation surface is kept vertical, so that sideslip resistance of the embankment is guaranteed.

The step edge requires straight tangent line, no edge gnawing phenomenon occurs, the tangent plane is smooth, no sandwich layer occurs, a certain width is reserved during excavation, and then the cutting is performed.

The old road at the joint is stepped so that each structural layer of the old road surface is provided with a step, and then a second socket 97 for being cooperatively connected with the precast reinforced concrete 91 is excavated on the step.

S4, construction of the cushion layer 21 and the subbase layer 22

The earthwork grille 10 is paved, the sandless macroporous concrete is paved, the mortar is compacted by a plate rammer, and then the cushion layer 21 and the subbase layer 22 are paved before the sandless macroporous concrete is finally set, so that the mortar layer and the subbase layer 22 are simultaneously rolled and formed with the sandless macroporous concrete, and simultaneously maintained. Then the prefabricated reinforced concrete 91 is spliced, and the inserting blocks 94 at the two ends of the strong spring 95 are respectively inserted into the first inserting groove 96 and the second inserting groove 97.

Under the influence of vibration in construction, collapse and void phenomena are easy to occur under the steps of the base layer 23, and the joint of the new base layer 23, the old base layer 22 and the old road base layer 23 are not easy to compact and form, so that weak parts are formed; meanwhile, widening the water-stable pavement subbase layer 22 can also obstruct the drainage function of the old pavement graded broken stone subbase layer 22, so that the water drainage is ensured by casting 0.5m wide sand-free macroporous concrete at the joint of the subbase layer 21 and the subbase layer 22, the sand-free macroporous concrete and the structure layer at the joint part are synchronously constructed during construction, and wet joint treatment is adopted for joints.

The sand-free macroporous concrete is spliced by adopting wet seams, so that seamless butt joint of spliced parts is ensured. When the sand-free macroporous concrete is discharged, the paving thickness is strictly controlled, the redundant concrete is moved to a position which does not reach the standard, the excessive casting is strictly forbidden, and when local uneven positions are found, the manual feeding or the trimming can be performed.

The sand-free macroporous concrete is compacted before the initial setting of the mixture until reaching the required compactness and void ratio, and the compaction is based on no aggregate damage.

In order to ensure the water permeability of the sand-free macroporous concrete, the rough surface is only required to be flattened, calendaring is not required, and after the mortar is poured to the elevation position, the constructor is strictly forbidden to disturb the formed concrete surface after compaction by rolling.

After the sand-free macroporous concrete is poured, the interior is filled with communicated macropores, free water is easy to be dispersed along with free flowing air, and further hydration of cement paste is affected, so that the surface must be continuously supplemented with water during curing, and the curing time must be no less than 7 days.

S5, construction of the base layer 23

Firstly, reinforcing bars are planted, then C40 concrete is poured to form a cast-in-situ concrete layer 7, then a base layer 23 is paved, and then vibration compaction is performed through a small flat plate type vibrator. The tie rod is arranged at the joint, steel bars 6 with the diameter of phi 25 and the length of 1.0m are adopted, the drilled holes are embedded into the original pavement 1, the embedded depth is 0.5m, and the longitudinal spacing is 0.3m.

The method of drilling and chemically planting the steel bars is adopted for the arrangement of the pull rods, the steel bar planting adhesive adopted for construction is subjected to a steel bar planting anchoring strength test before comprehensive construction, the pulling resistance is taken as a main test control parameter, and the steel bars 6 reach the control requirement of yield strength without pulling out on the premise of corresponding hole depths required by design. The test result can meet the matching of the depth of the planted bars and the pulling resistance and can be comprehensively implemented. The safety performance index of the bar planting glue meets the standard requirement, and the bar planting glue can enter the field after passing the inspection of the external commission.

Before the bar planting starts, positioning and paying off are firstly carried out, a drilling part is drawn by using a color chalk, drilling is carried out by using an electric hammer, drilling is stopped when the drilling depth is reached, and drilling depth and drilling diameter are measured;

After drilling holes into a batch, cleaning holes one by one, and when cleaning holes by using compressed air, firstly stretching a nozzle into the bottom of the holes, blowing clean oil-free compressed air, pulling out the nozzle outwards, and repeating for three times; inserting the bristle brush into the hole, and brushing three times in a reciprocating way; then the nozzle stretches into the bottom of the hole to blow air, the nozzle is pulled out, and the process is repeated for three times;

before the bar planting, acetone or industrial alcohol is used for wiping the hole wall and the hole bottom

S6, asphalt surface layer construction

The third glass fiber grille 5 is paved, the lower surface layer 24 is paved, the second glass fiber grille 4 and the middle surface layer 25 are paved after rolling and forming, then rolling is carried out, the first glass fiber grille 3 is paved at the joint of the original pavement 1 and the middle surface layer 25, and then the construction of the full-section upper surface layer 26 is carried out.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that numerous improvements and modifications can be made by those skilled in the art without departing from the principles of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.

Claims (3)

1. A construction method of a splicing structure of new and old road surfaces in highway engineering is characterized by comprising the following steps: the new old road surface mosaic structure of highway engineering, including former road surface (1) and new road surface, former road surface (1) is being close to new road surface one side is provided with step, its characterized in that: the novel pavement sequentially comprises a cushion layer (21), a base layer (22), a base layer (23), a lower layer (24), a middle surface layer (25) and an upper surface layer (26), wherein the upper surface layer (26) is paved on the tops of the middle surface layer (25) and the original pavement (1);

The foundation layer (21) and the subbase layer (22) are provided with a sand-free macroporous concrete drainage belt (8) at the joint with the original road surface (1), the sand-free macroporous concrete drainage belt (8) is paved by sand-free macroporous concrete, the base layer (23) is provided with a cast-in-situ concrete layer (7) at the joint with the original road surface (1), and the cast-in-situ concrete layer (7) is formed by casting C40 cement on site;

a steel bar (6) and a reinforcing piece (9) are arranged between the cast-in-situ concrete layer (7) and the original road surface (1), and the reinforcing piece (9) comprises a prefabricated reinforced concrete (91), an inserting block (94) and a strong spring (95);

the prefabricated reinforced concrete (91) is supported above the subbase layer (22) and is close to the joint of the new road surface and the original road surface (1), a first slot (96) is formed in the prefabricated reinforced concrete (91), a second slot (97) is formed in the step transversely spliced by the original road surface (1), two inserting blocks (94) are arranged, one inserting block (94) is inserted into the first slot (96), and the other inserting block (94) is inserted into the second slot (97);

The strong spring (95) is fixed between the two inserting blocks (94), and the construction method comprises the following steps:

s1, measuring and lofting: the pavement splicing seam positions are lofted, and the plane positions of pavement cushions (21) and sand-free macroporous concrete drainage belts (8) are lofted on a pavement;

S2, milling an old road: digging out a cement board and an asphalt layer additionally paved on the top of the cement board within the range of the original hard shoulder, and cutting off an old cement concrete panel with the thickness of the original hard shoulder not less than 0.35 m;

S3, step excavation: step excavation is carried out on the old road at the joint so that each structural layer of the original road surface (1) is provided with steps, and the width of each step which is transversely spliced is 35cm; a second slot (97) for being matched and connected with the prefabricated reinforced concrete (91) is excavated on the step;

S4, constructing a cushion layer (21) and a subbase layer (22): firstly, paving a soil engineering grid (10), paving sand-free macroporous concrete, compacting by ramming with a flat plate, paving a cushion layer (21) and a base layer (22) before final setting of the sand-free macroporous concrete, and simultaneously rolling and forming the cushion layer and the base layer and the sand-free macroporous concrete, and simultaneously curing; then splicing prefabricated reinforced concrete (91), and respectively inserting the inserting blocks (94) at two ends of the strong spring (95) into the first inserting groove (96) and the second inserting groove (97);

S5, constructing a base layer (23): firstly, reinforcing bars are planted, then C40 concrete is poured to form a cast-in-situ concrete layer (7), then a base layer (23) is paved, and then vibration compaction is performed through a small flat plate vibrator;

S6, asphalt surface layer construction: firstly, paving a third glass fiber grating (5), then paving a lower layer (24), paving a second glass fiber grating (4) and a middle surface layer (25) after rolling and forming, then rolling, finally paving a first glass fiber grating (3) at the joint of the original pavement (1) and the middle surface layer (25), and then performing full-section upper layer (26) construction.

2. The construction method of the splicing structure of new and old road surfaces in highway engineering according to claim 1, wherein the construction method comprises the following steps: when the reinforcing steel bar is planted, holes are drilled firstly, and then reinforcing steel bars (6) with phi 25 and the length of 1.0m are buried in the original road surface (1) with the buried depth of 0.5m.

3. The construction method of the splicing structure of new and old road surfaces in highway engineering according to claim 2, wherein the construction method comprises the following steps: before the bar planting starts, positioning and paying off are firstly carried out, a drilling part is drawn by using a color chalk, drilling is carried out by using an electric hammer, drilling is stopped when the drilling depth is reached, and drilling depth and drilling diameter are measured;

After drilling holes into a batch, cleaning holes one by one, and when cleaning holes by using compressed air, firstly stretching a nozzle into the bottom of the holes, blowing clean oil-free compressed air, pulling out the nozzle outwards, and repeating for three times; inserting the bristle brush into the hole, and brushing three times in a reciprocating way; then the nozzle stretches into the bottom of the hole to blow air, the nozzle is pulled out, and the process is repeated for three times;

Before the bar planting, acetone or industrial alcohol is used for wiping the hole wall and the hole bottom.