Assembly and construction method for pavement using reverse construction method

Abstract

This is an assembly and construction method using the reverse pouring method for pavement surfaces. [Solution] The assembly construction method of pavement using the upside-down construction method includes step 1, which is the production of prefabricated slabs, in which prefabricated slabs are made using the upside-down construction method, with bolt sleeves that penetrate vertically into the prefabricated slabs and the bolt sleeves are evenly distributed throughout the prefabricated slabs; and step 2, which is the installation of the prefabricated slabs, in which the prefabricated slabs are positioned all at once on top of the cleaned lower bearing plate in accordance with the installation sequence of the mounting segments, and then fine-tuning is made to the position and elevation of the prefabricated slab before grout injection construction is carried out, finally forming a complete paved road surface. The prefabricated slabs are first paved with bricks and then concrete is poured into them, and finally the mold is turned over and installed, which cancels the on-site concrete adhesion between the bricks and the lower bearing plate, increases the overall stability after the bricks and prefabricated slabs are installed, greatly reducing the phenomenon of bricks falling off during operation, perfectly achieving the assembly-type installation of paved road surfaces, while keeping construction costs down and accelerating construction time.

Description

[Technical Field]

[0001] The present invention relates to the technical field of construction of automobile test driving areas, and more particularly to a top-down construction type assembly construction method for paved road surfaces. [Background technology]

[0002] The low adhesion coefficient road surface in the test driving field is a road surface for testing the steering force control and stability control of the vehicle, and the most representative are basalt brick road and tile road, which are paved road surfaces. Such road surfaces must withstand large impact loads from high-speed vehicles, emergency braking, sudden steering, runaway turns, etc., which poses a great challenge to the smoothness and durability of such road surfaces.

[0003] Chinese Patent CN108582414A discloses a mold buckle and prefabricated construction method for road surface prefabricated blocks. A prefabricated base is cast using concrete, a steel slab is laid on the surface of the base, and a surrounding side mold is supported by the steel slab. The side mold then contains blocks containing tile bricks / basalt bricks, concrete, and rebar cages. Once the prefabricated blocks are fabricated, they are directly inverted so that the tile / basalt tile-paved side faces upward, and then laid onto the road surface. In this invention, the steel slab is leveled before the bricks are laid on the mold. Then, the prefabricated blocks are fabricated on the leveled steel plate, and finally, the prefabricated blocks are laid directly on the roadbed. However, due to the possibility of unevenness or inclination of the roadbed surface, the road surface may not be even after direct paving. This may cause an uneven water film on the road surface with a low adhesion coefficient during testing, which may affect the accuracy of the experimental data. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a method for assembling and constructing pavement surfaces by inverted construction, which solves or alleviates the problems present in the prior art. [Means for solving the problem]

[0005] To achieve the above object, the present invention provides the following technical solutions.

[0006] Step 1 is fabricating a prefabricated slab using a top-down method, wherein a bolt sleeve is provided vertically penetrating the prefabricated slab, and the bolt sleeve is evenly provided on the prefabricated slab; Step 2 is the installation of the prefabricated slab, which involves positioning the prefabricated slab on the cleaned lower bearing plate in accordance with the installation sequence of the installation segments, followed by fine tuning the position and elevation of the prefabricated slab, and then injecting grout to finally form a complete paved road surface; making fine adjustments to the position and elevation of the prefabricated slab; Rough adjustment of the elevation by screwing a leveling bolt into the bolt sleeve of each prefabricated slab, bringing the lower end of the leveling bolt into contact with the concrete surface of the lower bearing plate, and twisting the leveling bolt to raise the prefabricated slab until the elevation of the slab surface of the prefabricated slab matches the elevation of the hanging line. Lift the prefabricated slab slightly with a lifting device (crane device), manually (artificially) push the prefabricated slab to the required distance, and slowly lower the prefabricated slab, fine-tuning the position, For each prefabricated slab, the elevation of the four corner points of each prefabricated slab is measured with an electronic level, and after measuring all points and calculating the adjustment value, a unified adjustment sequence is planned, and the adjustment principle is equalization adjustment, and the leveling bolts are twisted according to the planned sequence, and the elevation is fine-tuned. In step 1, a prefabricated slab is fabricated on a super flat prefabricating pedestal, a side mold is attached and fixed, and then the bricks are reverse buckled onto the super flat prefabricating pedestal inside the side mold. The bricks are then arranged on the super flat prefabricating pedestal, which has been paved with a demolding barrier layer, and the brick joints and gaps between the bricks are filled with caulking strips. After the reverse paving of the bricks is completed, a first reserved hole mold is attached, and a layer of 8mm to 10mm thick polymer dry mix mortar is laid on the back of the bricks. After the polymer dry mix mortar has finally solidified, a first reinforcing mesh sheet and a second reserved hole mold are placed. A pre-embedding steel slab is installed, and bolt sleeves are fixed to the pre-embedding steel slab, with grouting holes drilled in the pre-embedding steel slab. After completing the above steps, concrete is poured to finally form a complete prefabricated slab. After the concrete strength reaches 75% of the design strength, the side mold is inverted with a sand pile in accordance with a crane. The flatness and specified dimensions of the brick surface of the prefabricated slab are inspected. For prefabricated slabs that pass the inspection, a caulking strip is immediately released and sewn in a timely manner, and the prefabricated slab is then numbered and stored. The second reserved hole mold and the first reserved hole mold are attached to correspond to the position of the bolt sleeve, and when concrete is poured inside the side mold, the inside of the second reserved hole mold and the first reserved hole mold are not poured, and the area corresponding to the first reserved hole mold is not filled, so that the holes are used for leveling and grout injection.

[0007] The prefabricated slab of the present invention is paved with bricks first, then concrete is poured, and finally the mold is turned upside down and installed, eliminating the on-site concrete adhesion between the bricks and the lower bearing plate, improving the overall stability after the bricks and prefabricated slab are installed, and significantly reducing the occurrence of brick falling off during operation of the road.

[0008] Based on the principle of "changing from small block laying to large block paving," this invention changes the paved road surface from a "small block" type paving to a "large block" assembly type installation, and combines a specially designed pre-embedding structure with artificial work to achieve a high-precision paving of prefabricated slabs paved with bricks, ensuring the stability and high precision of the flatness of the entire road surface. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram 1 of a design of a prefabricated slab according to an embodiment of the present invention. [Figure 2] 2 is a schematic diagram 2 of the design of a prefabricated slab according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram of a pre-embedded steel slab according to an embodiment of the present invention; [Figure 4] 1 is a schematic design diagram of a lifting hole pre-filling member according to an embodiment of the present invention; [Figure 5] 1 is a schematic diagram of a prefabricated slab before concrete is poured in accordance with an embodiment of the present invention. FIG. [Figure 6] 1 is a schematic diagram of the configuration of a prefabricated slab when pouring concrete according to an embodiment of the present invention. FIG. [Figure 7] 1 is a schematic diagram of the configuration of a prefabricated slab after concrete has been poured in accordance with an embodiment of the present invention. FIG. [Figure 8] 1 is a process diagram of reversing a prefabricated slab according to an embodiment of the present invention; FIG. [Figure 9] 10A and 10B are schematic diagrams illustrating a process for fine-tuning a position according to an embodiment of the present invention. [Figure 10] 1 is a schematic diagram of a "big block" assembly installation process according to an embodiment of the present invention. [Figure 11] FIG. 1 is a schematic diagram of the structure of a prefabricated slab after leveling and brick assistance in reserved grout injection holes according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The process mainly includes four steps: designing the prefabricated slab, preparing the prefabricated slab before casting, casting and maintenance of the prefabricated slab, and rolling the prefabricated slab. Step 1 is the production of the prefabricated slab, in which the present invention uses the inverted casting method to produce the prefabricated slab, and the bolt sleeves 3 are installed vertically inside the prefabricated slab, and the bolt sleeves 3 are evenly installed on the prefabricated slab. Step 2 is the installation of the prefabricated slab, in which the prefabricated slab is positioned on the cleaned lower bearing plate 2 in accordance with the installation sequence of the installation segments, and then fine adjustments are made to the position and elevation of the prefabricated slab before grout injection is carried out, finally forming a complete paved road surface. This is an assembly and construction method using the reverse construction method for paving road surfaces, including:

[0011] The basis for classifying the planar dimensions of prefabricated slabs is the design width of the roadway, the length of the roadway, the layout of expansion joints along the roadway, and the width of the designed brick joints. The principle of classification is to arrange an appropriate integer number of bricks in the length and width of the prefabricated slab. Most prefabricated slabs have the same dimensions, but the ends or smaller sections of the roadway are adjustable slabs with different dimensions. The width of the gap between slabs is the same as the width of the brick joints, and expansion joints are reserved (reserved) according to the designed width of the expansion joints to balance lifting capacity and lifting stability. The length and width of prefabricated slabs are generally less than 3m, and the thickness (including the thickness of brick 11) is controlled to around 25cm. The classification limit value of prefabricated slabs not only takes into account lifting capacity and lifting stability, but also takes into account that if the prefabricated slab is too large to withstand its own weight, it will cause warping deformation and destruction during the lifting and storage process. The dimensions of prefabricated slabs should not be too small, and too many slab joints will be disadvantageous to flatness control and effectively shorten the construction period.

[0012] The prefabricated slab must be inverted during the production installation process, and the reinforcement in the slab must follow a two-way double-layer design. The grout injection holes 4 and the pre-embedded lifting holes 7 must be installed between the double-layer reinforcing steel mesh sheet and firmly welded to the reinforcing steel mesh sheet. The concrete strength grade must be C30 or higher (the specific reinforcement and concrete strength can be calculated and designed based on the actual situation). The grout injection holes 4 must be left at the four corners of the prefabricated slab (one to two bricks from the edge of the prefabricated slab). The lifting holes must be installed on a pair of long sides to reduce the bending moment in the middle of the slab when lifting. Two lifting holes must be provided on each side to facilitate lifting. The bolt holes are installed at a distance of 0.21 times the side length from the end head, reducing the bending moment in the middle of the slab when it is lifted. For example, see Figures 1 and 2 for a design example of a prefabricated slab. Based on the design of the roadway width and length, brick joint width, etc., the prefabricated slab should be arranged with an integer number of blocks in the length and width directions, and the dimensions of the prefabricated slab should be unified, and lifting capacity and stability should be taken into consideration. The length and width of the prefabricated slab should be no more than 3m, and the thickness of the prefabricated slab should be around 25cm. The block area of ​​the prefabricated slab of this invention not only meets the economical requirements of 11 bricks, but its structural design also ensures the overall strength of the prefabricated slab and prevents deformation during storage, inversion, transportation, installation, etc.

[0013] For the test lane with low adhesion coefficient road surface, which is 200.895m long and 4.915m wide, the size of the prefabricated slab is 2455mm*2045mm, the size of the brick 11 is 200mm*200mm, the brick joint is 5mm, the total thickness of the prefabricated slab is 200mm, and it includes basalt brick with a thickness of 32mm, polymer dry mortar with a thickness of 8mm, and C35 reinforced concrete slab with a thickness of 160mm, and the size of the pre-embedded steel slab 10 is 360mm*360mm*20mm.

[0014] The pre-casting preparation of the prefabricated slab mainly includes three steps: processing and installing the side mold 1, back-buckling and arranging the bricks, and installing the reinforcing steel mesh sheet and pre-embedded components. Specifically, it includes processing the side mold 1, assembling the side mold 1, back-buckling and arranging the bricks, filling the brick joint mold, laying polymer dry blend mortar on the back of the bricks, installing the reinforcing steel mesh sheet, pre-embedded components, and the upper preliminary hole mold for the grout injection hole 4, pouring and maintaining the concrete, demolding the prefabricated slab, flipping the mold, sewing, storing, etc.

[0015] The processing and installation of the side mold 1 is as follows: The design principle of the side mold 1 is that the side mold 1 must have sufficient rigidity to prevent deformation during rotation, and the four sides of the prefabricated slab must protrude, reducing the adjustment room of the slab joint and preventing it from even being installed. After the side mold 1 is assembled, it must be ensured to present a relatively perfect rectangle to avoid diagonal twisting.

[0016] The side mold 1 is made of four thick-walled steel bars to ensure sufficient rigidity. A steel slab is installed at the joint of the end head to limit the position, and a 90-degree angle is forced to form after the template is connected. A release agent is applied before assembly. After assembly, the length and width, mold center width, diagonal length, and template verticality are inspected with an error of 1 mm to ensure that the dimensional accuracy after assembly meets the design requirements. Lifting holes are installed on the sides of the side mold 1, and the lifting holes are located 0.21 times the side length from the end head. There are two lifting holes on each side of the side mold.

[0017] A prefabricated slab is fabricated on an ultra-flattened prefabricated base, a side mold 1 is installed and fixed, and then bricks 11 are reverse-buckled onto the ultra-flattened prefabricated base inside the side mold 1. The bricks 11 are arranged on the ultra-flattened prefabricated base paved with a release barrier layer, and the brick joints are filled with caulking strips 9. After the reverse paving of the bricks 11 is completed, a first reserved hole mold is installed, and then a layer of polymer dry blend mortar with a thickness of 8 mm to 10 mm is laid on the back of the bricks. After the polymer dry blend mortar has finally solidified, a first rebar net sheet 5, a second reserved hole mold 14, a second rebar net sheet 6, and a pre-embedded steel slab 10 are installed, and a bolt sleeve 3 is fixed to the pre-embedded steel slab 10, but grout is injected into the pre-embedded steel slab 10. After the holes 4 are drilled and the steps are completed, concrete is poured to finally form a complete prefabricated slab. After the concrete strength reaches 75% of the design strength, the side mold 1 is inverted with a sand pile in accordance with the crane, and the flatness and specified dimensions of the brick surface of the prefabricated slab are inspected. For prefabricated slabs that pass the inspection, a caulking strip 9 is immediately applied and sewn in a timely manner, and the prefabricated slab is then numbered and stored. The second reserved hole mold 14 and the first reserved hole mold are installed corresponding to the positions of the bolt sleeves 3. When concrete is poured inside the side mold 1, the insides of the second reserved hole mold 14 and the first reserved hole mold are not poured, and the area corresponding to the first reserved hole mold is not filled, forming the reserved holes 12 for leveling and grout injection.

[0018] The side mold 1 is installed on an ultra-flat prefabricated base. After laying a barrier layer plastic film for base release, the side mold 1 is assembled on the barrier layer. The side mold 1 should be held lightly and left lightly during the rotation process, and placed on a flat surface to prevent collisions and to avoid deformation. A release agent should be applied in advance before each assembly, and a release agent should be applied after assembly to prevent contamination of the brick surfaces and backsides of the bricks inside the mold, which will affect the adhesive strength of the materials. After each demolding, the concrete slurry adhering to the mold surface should be immediately cleaned up. A wire brush should be used to clean up, and hammering should not be used. After each assembly, the length and width dimensions must be inspected, as well as the length and width of the template center and the lengths of the two diagonals. Regarding the straightness of the template, if a deformed template is found, it must be sent back to the manufacturer in a timely manner for mechanical calibration. It must not be calibrated on-site by hitting it with a large hammer. Templates that cannot be calibrated should be discarded, and new templates should be installed according to the progress of construction to prevent excessive deformation of the prefabricated slab.

[0019] Regarding the reverse buckling and placement of the bricks, the reverse buckling and placement of the bricks begins after the side mold 1 is assembled and inspected. Before placing the bricks, check whether the barrier layer plastic film is disturbed during the process of placing the side mold 1, and check whether there are any wrinkles or bubbles. If there are any, lift the side mold 1 slightly to flatten the barrier layer plastic film. According to the designed placement situation, place the bricks into the side mold 1 with the brick side facing down and temporarily insert them vertically into the brick joint using a caulking strip 9 to control the width of the brick joint. Before placing, check that there is no dirt or dust on the base surface and on the brick surface in the mold. If not, clean it thoroughly. The caulking strip 9 is made of hand-cut wooden strips and can be made to the required size. The width is the same as the designed brick joint, and the height is determined according to the fillet condition of the brick surface. After all the bricks 11 are placed, the interlocking wooden strips are inserted within the entire length of the brick joint until they contact the top surface of the base. Then, the bricks 11 are lightly tapped with a rubber hammer to ensure that each brick is placed and the brick surface is in close contact with the base surface. After that, the bricks 11 at the reserved holes 12 for leveling and grout injection are removed, and the first reserved hole mold is inserted into the space of the removed bricks 11. The recessed holes are square. The affected brick 11 and the first recessed hole mold are lightly tapped with a rubber hammer to make the brick surface and the first recessed hole mold tightly contact the base surface. A small amount of water is sprinkled on the back of the brick to moisten it, but not too much to prevent moisture buildup. Then, a layer of 8mm to 10mm thick polymer dry-mix mortar is laid on the back of the brick, leveled, and then rubbed with a slab and brush. The mortar is mixed with water according to the water amount specified in the product instructions and stirred evenly. After the dry-mix mortar on the back of the brick has solidified, the reinforcing steel mesh sheet can be installed.

[0020] For the installation of the reinforcing steel mesh sheet and pre-embedded components, the first reinforcing steel mesh sheet 5 and the second reinforcing steel mesh sheet 6 are processed on the processing shelf and tightly fastened. If there is a collision between the reinforcing steel and the reserved hole position, the position of the reinforcing steel is adjusted. After the dry blend mortar behind the brick has finally solidified, the reinforcing steel mesh sheet is placed into the mold. The first reinforcing steel mesh sheet 5 is cushioned by a concrete cushion block to form a protective layer under the concrete. The thickness of the protective layer under the concrete is 2±0.2cm. The second reinforcing steel mesh sheet 6 is made of a horseshoe. The first rebar net sheet 5 is supported by a stool, and a concrete upper protective layer with a thickness of 3±0.3 cm is formed on the upper side of the first rebar net sheet 5. Before the second rebar net sheet 6 is installed, pre-embedded members are installed. The pre-embedded members include a pre-embedded steel slab 10 and a lifting hole pre-embedded member 7 corresponding to the lifting hole. The pre-embedded steel slab 10 is welded to the first rebar net sheet 5. Then, a second reserved hole mold 14 is placed on the pre-embedded steel slab 10. Finally, the second rebar net sheet 6 is installed, and the lifting hole pre-embedded member 7 is fixedly connected to the first rebar net sheet 5 via connecting bars. Figure 3 is a schematic diagram of the pre-embedded steel slab structure.

[0021] The pre-filled lifting hole element 7 is an M32 bolt sleeve 3, which can be screwed onto the bolt lug to lift the prefabricated slab. When installing the pre-filled lifting hole element 7, the reserved lifting hole is aligned to support the inner wall of the side mold 1, and an M32 screw is screwed into it from the outside of the template, which stabilizes the pre-filled element and prevents the pre-filled lifting hole element 7 from being blocked by concrete slurry during pouring. The outer side of the pre-embedded lifting hole 7 is welded to the reserved lifting hole, and as shown in Figure 4, the inner side of the pre-embedded lifting hole 7 is welded through the connecting bar 8 and the reinforcing steel mesh sheet, and at the same time, the position of the reinforcing steel mesh sheet is also fixed. A bolt sleeve 3 is welded through the center of the pre-embedded steel slab 10. The bolt sleeve 3 is an M32 sleeve, and is welded through the pre-embedded steel slab 10. The sleeve length is not less than 5 cm. The bolt sleeve 3 can be screwed onto the leveling bolt 13 at the subsequent prefabricated slab installation site and made flat. A grout injection hole 4 is opened next to the bolt sleeve 3 in the pre-embedded steel slab 10. The pre-embedded steel slab 10 is placed on the first reserved hole mold, and then the auxiliary rib is used to insert the bolt sleeve 3. The first rebar net sheet 5 is welded and fixed to the first rebar net sheet 5, and then the second reserved hole mold 14 is placed on the pre-embedded steel slab 10, and finally the second rebar net sheet 6 is attached and the second reserved hole mold 14 is fixed through the second rebar net sheet 6, and the second reserved hole mold 14 is pressed onto the pre-embedded steel slab 10 with iron wire, with the proviso that the cross-sectional dimensions of the first reserved hole mold and the second reserved hole mold 14 are at least 5 cm smaller than the dimensions of the pre-embedded steel slab 10, and each side of the pre-embedded steel slab 10 is exposed at least 5 cm from the first reserved hole mold and the second reserved hole mold 14, to ensure that after concrete is poured, each side of the pre-embedded steel slab 10 is embedded in concrete by at least 5 cm. Figures 1 and 2 are schematic diagrams of the rebar mesh sheet configuration, Figure 3 is a schematic diagram of the pre-embedded steel slab configuration, and Figure 4 is a schematic diagram of the prefabricated slab configuration after the brick reverse buckling and placement are completed.

[0022] Concrete placement and maintenance includes the following: before concrete placement, a small amount of water should be applied to the surface of the dry-mixed mortar to moisten it; the concrete label should conform to the design requirements; the degree of collapse should be controlled to 80-120mm; each prefabricated slab should be placed at once; the concrete should be manually poured into the mold; the concrete should not be directly poured into the template from the tank truck; the concrete should be placed on a shim plate or cart equipped next to the template; the concrete should be manually scooped into the mold; and then vibrated with a small vibrating rod or flat slab vibrator. However, the rebars must not come into contact with the pre-embedded components or the bottom dry-mix mortar layer, and vibrations must not be too strong, especially at the locations of the pre-embedded components. After the concrete is poured, it must be immediately covered with plastic film, earthwork cloth, or insulation material according to the temperature conditions and maintained to keep the concrete surface moist and freezing-free. Before the prefabricated slab is transferred to its base, it must be kept warm, moist, watered, and maintained for at least 7 days. Figures 5, 6, and 7 are schematic diagrams of the prefabricated slab before, during, and after concrete pouring, respectively.

[0023] The specific steps for turning a prefabricated slab are as follows: When the temperature is above 15°C, the side mold 1 (with a demold strength of ≥ 2.5 MPa) is generally removed 24 hours after concrete pouring. The bolt lugs securing the pre-embedded elements 7 to the lifting holes must be removed before demolding. Retracting the bolt lugs should avoid disrupting the bond between the pre-embedded elements 7 and the concrete. After removing the side mold 1, continue to insulate, moisten, and maintain the concrete. Once the concrete strength reaches 75% of its design strength (after at least 7 days of maintenance), the prefabricated slab can be removed from the base. As shown in Figure 8, a sand pile is installed next to the prefabricated base to serve as the inversion site for the prefabricated slab. The sand pile is used to artificially align the crane with the inversion site. The purpose of using the sand pile to invert the prefabricated slab is to prevent the brick surface from colliding and being damaged during the unprotected inversion process.

[0024] During storage, two to three square timber mats should be placed under the prefabricated slabs, and each stacked and stored prefabricated slab should not be more than five stories high. Two to three square timbers should be placed between layers to separate them. The flatness and specified dimensions of the brick surfaces of the prefabricated slabs should be inspected. For prefabricated slabs that pass the inspection, the caulking strip 9 should be immediately removed and sewn in a timely manner. 48 hours after the stitching of the lower prefabricated slabs is completed, the prefabricated slabs should be stacked face up. Figure 1 shows a schematic diagram of the structure of a prefabricated slab when the caulking strip 9 has not been removed after inversion. At the same time, the prefabricated slabs should be numbered and labeled, and special distinctions should be made between prefabricated slabs with different model numbers.

[0025] The installation of prefabricated slabs mainly involves the steps of prefabricated slab layout, rough adjustment of elevation, fine adjustment of position, fine adjustment of elevation and grout injection, and can be divided into the steps of construction of the lower bearing plate 2, installation and grout injection planning, prefabricated slab layout, rough adjustment of elevation, fine adjustment of position, fine adjustment of elevation, leveling and grout injection reservation hole brick arrangement, and stitching between slabs.

[0026] For the layout of prefabricated slabs, a grid is pre-drawn on the concrete surface of the lower bearing plate 2. When the prefabricated slabs are positioned in one go according to the installation sequence of the installation segments, clamping strips of the same width as the slab joints are created to control the gap between the slabs. The clamping strips are used to control the gap between the slabs when they are being positioned. The clamping strips are placed near the four corners of the prefabricated slabs to ensure that they fall within the grid during the installation process. The installation sequence is generally carried out gradually from one end to the other. It is recommended that the corresponding prefabricated slab is transported from the prefabricated slab storage location to the installation site using a transport vehicle with an attached crane. After the prefabricated slab arrives at the installation site, it is hung directly in its installation position (within the grid), allowing the prefabricated slab to be positioned as accurately as possible in one go, reducing the amount of work required for fine-tuning later. For example, Figure 10 is a schematic diagram of the process of converting a "small block" prefabricated slab into a "large block" prefabricated installation. When the slabs are placed, clamping strips are used to control the gap between the slabs to prevent the plates from colliding with each other and collapsing the brick surface during their fall. The clamping strips must be placed near the four corners of the prefabricated slab. The error at the corners of the prefabricated slab is generally small, and the middle part may protrude due to deformation of the side mold 1 of the prefabricated slab. This can cause the slab joint to be too wide, and the error can accumulate and cause the prefabricated slab to exceed the range of the installation section. Therefore, during the slab placement process, it is necessary to regularly check whether the plates can fall within the ink grid. If there is a problem, adjustments can be made in a timely manner to evenly compensate for the error, thereby ensuring that the final overall length of the roadway meets the design requirements.

[0027] However, the steps for making fine adjustments to the position and elevation of the prefabricated slab are: coarse elevation adjustment, fine position adjustment, fine elevation adjustment, and end of pouring.

[0028] In order to reduce the amount of measurement work required for rough adjustment of elevation, the rough adjustment uses a sampling control stake to level the hanging line, adjusts the elevation of the standard plate at a certain distance, and uses the hanging line to adjust the elevation of the remaining plates. Before rough adjustment, the leveling bolts 13 are screwed into the bolt sleeves 3 of each prefabricated slab 10, and the lower ends of the leveling bolts 13 are brought into contact with the concrete surface of the lower bearing plate 2. The leveling bolts 13 are then twisted to raise the prefabricated slabs until the elevation of the slab surface of the prefabricated slab matches the elevation of the hanging line. Because the prefabricated slabs are heavy, the bolts can be turned with force and large torque. A special "T"-shaped sleeve wrench can be added and a long rotating handle can be welded to the top. Each prefabricated slab 10 is equipped with four bolt sleeves 3. When roughly adjusting the elevation, two workers simultaneously rotate the leveling bolts 13 in one direction, gradually adjusting the four bolts of the same prefabricated slab 10 in a balanced manner. Each bolt is turned a maximum of one or two times, and then the next bolt is turned. This is repeated until the elevation of the slab surface of the prefabricated slab 10 matches the elevation of the hanging line. If the adjustment height of one bolt is too large, the prefabricated slab will tilt and displace, pushing the adjacent prefabricated slab and causing it to shift position, resulting in the longitudinal and transverse slab joints not fitting together.

[0029] During fine adjustment, the prefabricated slab should be lifted slowly and evenly. After the rough adjustment of the elevation, the position of the prefabricated slab may still shift slightly, requiring fine adjustment. As shown in Figure 9, the lifting device should be used to slightly lift the prefabricated slab, then manually push it to the required distance, and then slowly lower it. It is strictly prohibited to use a crowbar to pry it apart using the adjacent prefabricated slab as a fulcrum, as this will cause the prefabricated slab brick surface to collapse. As shown in Figure 9, a simple hanger should be used to align the hoist crane, and the nut heads of the leveling bolts 13 should be used as the lifting point to lift the prefabricated slab a short distance. The tips of the leveling bolts 13 should be able to easily separate from the lower bearing plate 2. Then, using the reserved holes for leveling and grout injection as the force point, the prefabricated slab should be pushed to the required position, stabilized, and then the prefabricated slab can be slowly placed. The positioning should take into account the overall surface, and a hanging line method should be used to ensure that the vertical and horizontal slab joints are straight and uniform. When aligning the prefabricated slabs and fine-tuning the elevation, the final fine-tuning of the elevation is carried out after the fine-tuning of the position is completed. For each prefabricated slab, the elevation of the four corner points of each prefabricated slab is measured with an electronic level and the difference from the design value is calculated. It is not possible to measure one point and adjust one point; after measuring all points and calculating the adjustment value, a unified adjustment sequence is planned. The adjustment principle is equalization adjustment. The leveling bolts 13 are twisted according to the planned sequence. It is not possible to adjust one bolt too high at a time, because doing so will shift the plate. When fine-tuning the elevation, each bolt is adjusted half a turn at a time, and then the next bolt is adjusted in a cycle. After adjustment, it is necessary to ensure that each bolt is in effective contact with the surface of the lower bearing plate 2 to prevent the prefabricated slab from shaking. When adjusting the elevation, a ruler should also be used to check the flatness between the ruler and the surrounding prefabricated slabs to ensure that it meets the flatness requirements of the design. If the deviation in flatness is large, it should first be checked whether the elevation between the prefabricated slab and the surrounding prefabricated slabs has changed due to contact during the adjustment process.If the elevation is accurate, large deviations in general flatness will not appear, and small flatness deviations can be considered for removal by fine-tuning the elevation.

[0030] At the end of injection, after the fine adjustment of one mounting segment is completed, grouting must be carried out in a timely manner. Before grouting, dust and impurities in the leveling space are purged with compressed air through the grout injection hole 4 to ensure that there is no dust in the grout injection hole 4 or the de-airing area. The grout injection holes 4 are reserved at the four corners of the prefabricated slab 10, at a distance of 1 to 2 bricks from the edge of the prefabricated slab 10. The diameter of the grout injection holes 4 is φ20 mm. Before grouting, high-grade cement mortar is used to seal the gaps and slab joints between the surrounding prefabricated slab and the lower bearing plate to prevent slurry from leaking from the grout injection area. Preferably, the slurry injection material is a slightly expanded concrete prestressed hole slurry with high strength, good fluidity, no water secretion, no layer separation, good durability, and early strength. Next, grouting is used to fill the leveling space between the prefabricated slab and the surface of the lower bearing plate 2, and the gaps between adjacent prefabricated slabs, making them dense and free of holes. To prevent the panels from lifting during the grouting process, an electronic level is used to monitor in real time whether the prefabricated slabs are lifting during the grouting process. After grouting is completed, the elevation and flatness of all prefabricated slabs are immediately inspected and the elevation and flatness are adjusted in a timely manner before the slurry solidifies. After grouting is completed, bricks 11 are assisted in attaching the leveling and grouting reserved holes 12, and the prefabricated slabs 10 are sewn together. After sewing, the road surface is cleaned and the installation of the prefabricated slab road surface is completed. Figure 11 is a schematic diagram of a prefabricated slab attached with the assistance of bricks 11.

[0031] The present invention uses an inverted construction method to fabricate prefabricated slabs, ensuring the durability and flatness of the brick surface on top of the prefabricated slabs. When installing the prefabricated slabs, high-precision installation of the prefabricated slabs is achieved through initial positioning, rough adjustment of the elevation, fine adjustment of the position, and fine adjustment of the elevation, ensuring the stability and high-precision flatness of the entire road surface. Moreover, compared with artificial on-site paving, construction costs are kept low and construction time is shortened. [Explanation of symbols]

[0032] 1 Side mold 2 Lower Bearing Plates 3 Bolt sleeve 4 Grout injection hole 5. First Reinforced Concrete Net Sheet 6 Second rebar net sheet 7 Lifting hole pre-embedded material 8 Connecting bars 9 caulking strips 10 Pre-embedded steel slabs 11 Brick 12 Leveling and grouting holes 13 Leveling bolt 14 Second reserved hole mold

Claims

1. Step 1 is the production of a prefabricated slab, which is produced using a reverse construction method, wherein bolt sleeves are provided vertically penetrating the prefabricated slab, and the bolt sleeves are evenly provided on the prefabricated slab; Step 2 is the installation of the prefabricated slab, which involves positioning the prefabricated slab on the cleaned lower bearing plate in accordance with the installation sequence of the installation segments, then making fine adjustments to the position and elevation of the prefabricated slab, and then injecting grout to finally form a complete paved road surface; making fine adjustments to the position and elevation of the prefabricated slab; Rough adjustment of elevation by threading a leveling bolt into the bolt sleeve of each prefabricated slab, bringing the lower end of the leveling bolt into contact with the concrete surface of the lower bearing plate, and twisting the leveling bolt to raise the prefabricated slab until the elevation of the slab surface of the prefabricated slab matches the elevation of the hanging line; Lift the prefabricated slab slightly with the lifting device, manually push the prefabricated slab to the required distance, and then slowly lower the prefabricated slab, fine-tuning the position, For each prefabricated slab, the elevation of the four corner points of each prefabricated slab is measured using an electronic level, and after measuring all points and calculating the adjustment value, a unified adjustment sequence is planned, and the adjustment principle is equalization adjustment, and the leveling bolts are twisted according to the planned sequence, and the elevation is fine-tuned. In step 1, a prefabricated slab is fabricated on an ultra-flattened prefabricated base, a side mold is installed and fixed, and then the bricks are reverse-buckled to the ultra-flattened prefabricated base inside the side mold. The bricks are arranged on the ultra-flattened prefabricated base paved with a release barrier layer, and the brick joints are filled with caulking strips. After the bricks are reverse-paved, a first reserved hole mold is installed, and then a layer of 8mm to 10mm thick polymer dry blend mortar is laid on the back of the bricks. After the polymer dry blend mortar has finally solidified, a first rebar net sheet, a second reserved hole mold, and a second 2. Install the reinforcing steel net sheet and the pre-embedded steel slab, and fasten the bolt sleeve to the pre-embedded steel slab, which has grout injection holes. After completing the above steps, pour concrete to finally form a complete prefabricated slab. After the concrete strength reaches 75% of the design strength, use the crane to flip the side mold with sand piles. Check the flatness and specified dimensions of the brick surface of the prefabricated slab. For the prefabricated slabs that pass the test, immediately release and sew the caulking strips in a timely manner, and then number and store the prefabricated slabs. The second reserved hole mold and the first reserved hole mold are attached to correspond to the position of the bolt sleeve, and when concrete is poured inside the side mold, the insides of the second reserved hole mold and the first reserved hole mold are not poured, and the area corresponding to the first reserved hole mold is not filled, so that the holes are used as reserved holes for leveling and grout injection.

2. 2. The method for assembling and constructing pavement using the inverted pouring method of claim 1, wherein each prefabricated slab is provided with four bolt sleeves. During rough elevation adjustment, two workers simultaneously rotate the leveling bolts in one direction, gradually adjusting the four bolts of the same prefabricated slab in a balanced manner, turning one bolt a maximum of one or two times before rotating the next bolt, and repeating this process until the elevation of the slab surface of the prefabricated slab matches that of the hanging line. During fine elevation adjustment, each bolt is adjusted half a turn before adjusting the next bolt, and so on. After adjustment, it is necessary to ensure that each bolt is in effective contact with the surface of the lower bearing plate to prevent the prefabricated slab from shaking. During elevation adjustment, a ruler is used to check the flatness between the ruler and the surrounding prefabricated slabs to ensure that the flatness requirements of the design are met.

3. 2. The method for assembling and constructing pavement using the inverted pouring method described in claim 1, wherein in step 2, a marking grid is pre-drawn on the concrete surface of the lower bearing plate, and when the prefabricated slabs are positioned all at once according to the installation sequence of the mounting segments, clamping strips are made with sticks of the same width as the slab joints to control the gap between the slabs, and when the slabs are positioned, the clamping strips control the gap between the slabs, and the clamping strips are positioned close to the four corners of the prefabricated slabs to ensure that the prefabricated slabs fall into the marking grid during the slab placement process.

4. 2. The method for assembling and constructing pavement using the inverted pouring method according to claim 1, wherein in step 2, after the fine-tuning of one mounting segment is completed, grouting is required in a timely manner. Before grouting, high-index cement mortar is used to seal the gaps and slab joints between the surrounding prefabricated slabs and the lower bearing plate, and then grouting is used to fill the leveling space between the prefabricated slabs and the surface of the lower bearing plate and the gaps between adjacent prefabricated slabs. An electronic level is used to monitor in real time whether the prefabricated slabs are lifting during the grouting process. After grouting is completed, the elevation and flatness of all prefabricated slabs are immediately inspected and the elevation and flatness are adjusted in a timely manner before the slurry solidifies.

5. 5. The method for assembling and constructing a pavement surface by inverted construction method according to claim 4, characterized in that before grouting, dust and impurities in the leveling space are purged with compressed air through the grout injection holes.

6. 2. The method for assembling and constructing pavement surfaces using the inverted pouring method described in claim 1, characterized in that the grout injection holes are reserved at the four corners of the prefabricated slab and at a distance of one to two bricks from the edge of the prefabricated slab, and the diameter of the grout injection holes is φ20 mm.

7. 2. A method for assembling and constructing pavement surfaces using the inverted construction method described in claim 1, characterized in that after grouting is completed, bricks are assisted and attached to the reserved holes for leveling and grout injection, and the prefabricated slab is sewn, and after sewing, the road surface is cleaned and the installation of the prefabricated slab road surface is completed.

8. 2. The method for assembling and constructing pavement surfaces using the inverted pouring method described in claim 1, wherein the first reinforcing bar net sheet cushions the lower concrete protective layer with concrete cushion blocks, and the thickness of the lower concrete protective layer is 2±0.2 cm; the second reinforcing bar net sheet is supported on the first reinforcing bar net sheet via a hose stool; an upper concrete protective layer having a thickness of 3±0.3 cm is formed on the upper side of the first reinforcing bar net sheet; pre-embedding members are attached before the second reinforcing bar net sheet is attached; the pre-embedding members include a pre-embedding steel slab; the pre-embedding steel slab is welded to the first reinforcing bar net sheet; subsequently, a second reservation hole mold is placed in the pre-embedding steel slab; and finally, the second reinforcing bar net sheet is attached.

9. A method for assembling and constructing pavement surfaces using a reverse pouring method as described in claim 8, characterized in that lifting holes are provided on the side edges of the side mold, the lifting holes are provided at a position 0.21 times the side length from the end head, two lifting holes are provided on each side of the side mold, the pre-embedding members include lifting hole pre-embedding members corresponding to the lifting holes, and the lifting hole pre-embedding members are fixedly connected to the first reinforcing bar net sheet via connecting bars.

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