T-beam wing plate subsection supporting post-tensioning unbonded prestress assembly road and construction method

Abstract

The invention relates to the technical field of road construction, in particular to a T-beam wing plate subsection supporting post-tensioning unbonded prestressed fabricated road and a construction method.The fabricated road comprises a gravel cushion layer, a fine aggregate concrete layer, a laminated beam, a laminated plate, a T-beam wing plate, a concrete grouting material and unbonded prestressed tendons; according to the technical scheme, T-beam wing plate segmented supporting, segmenting, module dividing, laminated beam plate hoisting in all intervals, post-pouring joint part sleeve grouting connection at the T-beam wing plate, flexible sealing strip seam sealing between laminated plates, post-tensioning method prestress applying, high-pressure grouting and asphalt concrete surface layer comprehensive paving are adopted, bearing is reliable, and construction is efficient.

Description

Technical Field

[0001] This invention relates to the field of prefabricated road technology, specifically to a T-beam flange segmented support post-tensioned unbonded prestressed prefabricated road and its construction method. Background Technology

[0002] Traditional wet construction methods incur significant costs in terms of manpower, materials, and machinery, have extremely long construction cycles, cause substantial traffic disruptions, and generate considerable environmental pollution. While the publicly available prefabricated road structure technologies have pioneered the research and application of new prefabricated road construction technologies in my country and pointed the way for future road construction, many prefabricated components are assembled for the sake of assembly, without considering the structural integrity of segments and modules after grouting. The prefabricated components are often simply spliced ​​together, resulting in unclear stress transmission paths and compromises on the overall seismic resistance of the structure. They merely serve to fix boundaries and act as grouting templates, representing only a technological innovation.

[0003] In the process of promoting the construction of prefabricated roads, we still face several prominent bottlenecks, such as the lack of a unified standard for structural design, the need for further verification of node connection performance, the lack of obvious cost advantages of large-scale construction, and the insufficient allocation of professional and technical personnel. Summary of the Invention

[0004] The purpose of this invention is to provide a method for constructing a road with segmented support of T-beam flanges and post-tensioned unbonded prestressed concrete, in order to solve the problems raised in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a T-beam flange-supported post-tensioned unbonded prestressed assembled road, comprising a gravel cushion layer, a fine aggregate concrete layer, a composite beam, a composite slab, a T-beam flange, concrete grouting material, and unbonded prestressing tendons. A fine aggregate concrete layer is provided on top of the gravel cushion layer, and composite beams are provided at both ends of the fine aggregate concrete layer. Positioning reinforcing bars are pre-embedded in the top of the composite beams, and pre-reserved through holes are also provided inside the composite beams. The composite slabs rest on the top of the composite beams at both ends, and perforated connecting steel plates are pre-embedded at the ends of the composite slabs resting on the top of the composite beams. The perforated connecting steel plates are reliably connected to the positioning reinforcing bars pre-embedded in the top of the composite slabs. The T-beam flanges are arranged in segments perpendicular to the longitudinal direction of the road. The ends are equipped with exposed reinforcing bars, which extend into both sides of the road to form post-cast connection nodes with the composite beams. The post-cast connection nodes are cast with fine aggregate concrete. A post-cast joint is formed between the T-beam flange and the adjacent composite slab. The exposed reinforcing bars on the sides of the T-beam flange and the composite slab within the post-cast joint are connected by grouting with reinforcing bar sleeves. Grouting holes and overflow holes are provided inside the composite slab. Concrete grout is injected into the internal cavity of the structure under high pressure through the grouting holes. Unbonded prestressed tendons are provided between two adjacent composite beams in the transverse direction of the road. The two ends of the unbonded prestressed tendons pass through the reserved holes inside the composite beams. The unbonded prestressed tendons are fixed to the outer side ends of the composite beams with anchors. An asphalt concrete surface layer is provided on the upper part of the composite slab.

[0006] Preferably, the composite beam, composite slab, and T-beam flange are all prefabricated in a prefabricated PC factory. The cross-section of the composite beam is not less than 100mm × 150mm, and the prefabricated length of each composite beam segment does not exceed 6.0m. The positioning reinforcement at the top of the composite beam is located in the middle of the composite beam cross-section. The diameter of the positioning reinforcement is not less than 20mm. The length of the positioning reinforcement embedded in the composite beam is not less than 1 / 3 of the height of the composite beam and not less than 80mm. The length of the positioning reinforcement exposed at the top of the composite beam is not less than 60mm. The positioning reinforcement is evenly distributed along the length of the composite beam, and the spacing between adjacent positioning reinforcements does not exceed 200mm. The reserved perforation positions inside the composite beam correspond to the positions of the unbonded prestressing tendons. The diameter of the reserved perforation is 3mm to 5mm larger than the outer diameter of the unbonded prestressing tendons. The reserved perforation uses externally threaded steel pipes and is completed as an integral part with the composite beam PC factory prefabrication. The lower part of the composite beam is equipped with embedded tie bars. The extended length of the embedded tie bars is not less than 300mm and the diameter is not less than 12mm. The embedded tie bars are arranged along the length of the composite beam, and the distance between the embedded tie bars does not exceed 450mm. The top of the embedded tie bars is equipped with an anchor plate. The embedded tie bars at the bottom of the composite beam and the end anchor plates extend into the fine stone concrete layer of the road structure.

[0007] Preferably, the composite slab has grouting holes and overflow holes inside, which are pre-embedded and integrated during the prefabrication process of the composite slab. The grouting holes are in the shape of a "truncated cone", and the overflow holes are in the shape of an "inverted truncated cone". The grouting holes and overflow holes are designed to be of equal size, with a small diameter of 50mm and a large diameter of 80mm. A perforated connecting steel plate is set at the end of the composite slab where it is supported by the composite beam. It is set along the width of the composite slab, with the perforated connecting steel plate extending into the beam-slab connection node by a width of not less than 80mm. The perforated connecting steel plate is anchored into the composite slab by not less than 40mm. The diameter of the hole on the perforated connecting steel plate is 2mm larger than the diameter of the positioning reinforcement at the top of the composite slab, and the connecting holes on the perforated connecting steel plate correspond one-to-one with the positions of the positioning reinforcement, with the positioning reinforcement inserted into the hole of the perforated connecting steel plate. The connection node between the composite beam and the composite slab is a post-cast node, and fine aggregate concrete with the same strength as the main structure concrete is used to cast the post-cast node.

[0008] Preferably, the T-beam flange is the starting node of each construction section, the distance between adjacent T-beam flanges does not exceed 70m, the width of the post-cast joint between the T-beam flange and the adjacent composite slab is not less than 500mm, the exposed steel bars on the side of the T-beam flange and the exposed steel bars on the side of the composite slab are the same in size and specification, corresponding one-to-one, and are connected by 100% steel bar sleeve grouting; the contact surface between the T-beam flange and the composite slab at the post-cast joint is roughened, with a roughness of not less than 85%; the exposed steel bars at the beam end of the T-beam flange form a post-cast connection node with the segmented composite beam, and the exposed steel bars are longitudinally arranged inside the T-beam flange and extend outward to its end, with an outward extension length of not less than 350mm.

[0009] Preferably, the unbonded prestressing tendons are placed in the cavity between the fine aggregate concrete layer and the composite slab. The unbonded prestressing tendons pass through the pre-reserved holes inside the composite beam using a perforation method at the composite beam. The spacing between the unbonded prestressing tendons is consistent with the pre-reserved holes designed inside the composite beam, and the spacing does not exceed 1500mm. The anchorage is sealed with "sulfur mortar waterproof and crack-resistant mortar". In the post-cast joint area where the T-beam flange connects to the composite slab on both sides, 1 to 2 more unbonded prestressing tendons are added.

[0010] Preferably, it also includes a flexible weather-resistant sealing strip, which is set between the joints of two adjacent composite slabs. The length of the flexible weather-resistant sealing strip is 10mm longer than the net distance between the two transverse composite beams of the road. The width of the flexible weather-resistant sealing strip is not less than 30mm, and the thickness is the design width of the composite slab joint + 3mm. The concrete grout is injected into the structure through the grouting holes inside the composite slab using a high-pressure grouting method. Micro-expansion, low-shrinkage fine stone concrete grout is used. The strength of the concrete grout should be at least one grade higher than the design concrete strength of the main structure and not lower than C35.

[0011] Simultaneously, it provides the construction method for post-tensioned unbonded prestressed assembled roads with segmented support of T-beam flanges. The construction process is as follows: surveying and setting out the road alignment, laying the gravel subbase, positioning and hoisting the composite beam, adjusting the embedded tie bars, installing the anchor plate, pouring the fine stone concrete layer, laying the unbonded prestressed tendons, hoisting and positioning the T-beam flanges, adjusting the exposed reinforcement bars of the flanges, hoisting the composite slabs in segments and modules, perforating the positioning reinforcement bars, connecting the reinforcement sleeves at the post-cast joints, pouring the concrete at the composite beam-slab joints, installing the flexible weather-resistant sealing strip, high-pressure grouting of the concrete grout, tensioning and anchoring the unbonded prestressed tendons, and fully paving the asphalt concrete surface layer.

[0012] The preferred technical solution is as follows:

[0013] Step S1: Measure and lay out the road alignment, and lay the gravel subbase:

[0014] According to the technical plan, the road alignment will first be surveyed in sections using a total station to preliminarily determine the road's direction. Obstacles within the road construction area will be removed mechanically, and the original roadbed will be reinforced. Then, the surface of the roadbed soil will be appropriately solidified using a "sprayed cement grout" method. After the cement grout has been left to stand for at least 6 hours, a sand and gravel cushion layer will be laid in sections, with a minimum actual thickness of 100mm. During the on-site section laying of the sand and gravel cushion layer, a method of "two-stage paving, two-stage compaction, and one-stage spraying" will be adopted. The construction of the sand and gravel cushion layer is carried out in a two-stage laying sequence of "crushed stone - coarse sand - crushed stone - coarse sand". After the two layers of coarse sand are laid, they are compacted by machinery. The compaction is completed in two stages. Finally, the surface of the sand and gravel cushion layer is slurry mixed with cement. The cement mortar spraying should be able to fully penetrate the sand and gravel cushion layer. When the slurry does not sink significantly on the surface of the sand and gravel cushion layer and a small amount of slurry remains on the surface of the sand and gravel cushion layer, it means that the spraying process is qualified. The construction is carried out in sections, and the process is inspected and recorded.

[0015] Step S2: Positioning and hoisting of composite beams:

[0016] The composite beams must be prefabricated in the PC factory until they reach 100% of their design strength before being transported to the construction site. During transportation, the positioning reinforcement bars, embedded tie bars, and anchor plates at the ends of the embedded tie bars on the composite beams must be carefully protected. No quality issues should arise due to transportation affecting the appearance quality of the composite beams, severe deformation or breakage of the positioning reinforcement bars or embedded tie bars, or loosening or loss of the anchor plates at the ends of the embedded tie bars. Upon arrival at the site, prefabricated composite beams must be inspected by designated personnel; only those that pass inspection can be brought to the site. The on-site hoisting of the composite beams will be located on the top surface of the sand and gravel cushion layer. The placement of the composite beams is based on the position of the upper reinforcing bars of the two adjacent crossbeams. Strict control must be exercised over the distance between these upper reinforcing bars to improve efficiency for subsequent composite slab hoisting and ensure the maximum deviation of the distance between the upper reinforcing bars of the two adjacent crossbeams is within 3mm. It is important to note that the positional relationship of the composite beams should be properly adjusted using grouting before on-site placement, especially the elevation after hoisting. The elevation should be controlled based on the top surface elevation of the placed composite beams, with a maximum error within 5mm.

[0017] Step S3: Adjust the pre-embedded tie rods and install the anchor plate:

[0018] According to the technical plan, the positioning steel bars at the top of the composite beam need to be connected to the perforated connecting steel plates on the composite slab through holes in the subsequent process. The pre-embedded tie bars at the bottom of the composite slab need to be anchored into the fine stone concrete cushion layer above the sand and gravel cushion layer. After the composite beam is hoisted and positioned in sections, the positioning steel bars at the top of the composite beam and the pre-embedded tie bars at the bottom need to be reasonably adjusted, and the anchor plates at the ends of the pre-embedded tie bars need to be inspected and re-tightened to ensure that each anchor plate is reliably fixed to the pre-embedded tie bar, and 100% of the anchor plates are installed. At the same time, in order to effectively cooperate with the pouring of the fine stone concrete layer in the subsequent process, after the pre-embedded tie bars and anchor plates are processed, the top surface elevation line of the fine stone concrete pouring is projected onto the inner side of the precast composite slab above the pre-embedded tie bars using a chalk line, and the process acceptance work is carried out.

[0019] Step S4: Pouring of fine aggregate concrete layer and laying of unbonded prestressed tendons:

[0020] As a crucial component for stabilizing the roadbed, limiting the composite beams, and strengthening the overall structural load-bearing system, the fine aggregate concrete layer can be poured after the pre-embedded tie bars and anchor plates are adjusted. The fine aggregate concrete is poured in sections in a single pour. The elevation of the top surface of the fine aggregate concrete is based on the chalk line already marked on the inner side of the precast composite slab above the pre-embedded tie bars, avoiding blind pouring and repeated elevation measurements. The strength grade of the fine aggregate concrete poured on-site is not lower than C25. Vibration and curing are strengthened to improve the compactness and finished product quality of the fine aggregate concrete. Unbonded prestressing tendons can only be laid after the fine aggregate concrete layer has cured to a strength of 1.2 MPa. The unbonded prestressing tendons are laid directly on-site, with both ends of the unbonded prestressing tendons passing through the precast composite beams and temporarily anchored to the outer side of the composite beams.

[0021] Step S5: Hoisting and positioning of the T-beam flange, and adjusting the exposed reinforcing bars on the flange:

[0022] On-site construction was organized in a continuous flow. After the prestressed tendons were laid in sections, the T-beam flanges could be hoisted and positioned. The T-beam flanges were designed as the starting nodes for adjacent longitudinal construction sections of the prefabricated road, with a distance of no more than 70m between adjacent T-beam flanges. The T-beam flanges, combined with composite beams and composite slabs, formed the core technology system of composite beams and slabs for prefabricated roads. Therefore, the on-site T-beam flanges formed a reinforced post-cast joint connecting adjacent construction sections in the longitudinal direction of the road, playing a crucial role in improving the overall construction quality of the road. During the on-site hoisting of the T-beam flanges, in the fine aggregate concrete... The T-beam flange elevation can also be adjusted and treated by grouting on the concrete top surface. The two ends of the T-beam flange form a post-cast connection node with the composite beam. The exposed steel bars at the ends of the T-beam flange must be strictly anchored into the post-cast node according to the design requirements. After the T-beam flange is hoisted into place, the positional relationship and elevation of the T-beam flange should be accurately checked, and the exposed steel bars on the sides of the T-beam flange and the composite slab should be effectively straightened. A dedicated person should be assigned to supervise the process. If the T-beam flange is not positioned properly or the exposed steel bars are not adjusted properly, remedial measures should be taken, and process acceptance records should be kept.

[0023] Step S6: Segmented and modular hoisting of the composite slab, positioning and drilling of reinforcing bars:

[0024] According to the technical solution, the composite floor slabs are hoisted and supported at the ends of the composite beams for a length of not less than 10mm. The perforated connecting steel plates pre-embedded at the ends of the composite slabs and the positioning reinforcing bars pre-embedded in the upper part of the composite beams are fixed in place using a "mechanical perforation method." The perforated connecting steel plates at the ends of each composite slab and the positioning reinforcing bars pre-embedded in the upper part of the composite beams correspond one-to-one in planar position. The slabs are hoisted sequentially in sections and modules. The composite slabs are hoisted using a four-point horizontal lifting method, slowly lowered above the road structure, allowing the perforated connecting steel plates at the ends of the composite slabs to be properly positioned. The orifice on the beam is precisely aligned with the positioning reinforcement bars extending outward from the top of the composite beam. The beam is then slowly lowered, and steel shims are used to fine-tune the positioning elevation of both. After all the composite slabs in each construction section are hoisted into place, the perforated connecting steel plates and positioning reinforcement bars are spot-welded and fixed one by one using the welding method. During the on-site hoisting process, a 5mm to 10mm joint is left between adjacent composite slabs. During the hoisting of the composite slabs, steel plates of corresponding size are used to limit the ends to ensure that the joint size between all adjacent composite slabs is equal, so as to facilitate the uniform installation of the flexible weather-resistant sealing strips later.

[0025] Step S7: Post-cast reinforcement sleeve connection at the joint, concrete pouring for the composite beam-slab joint:

[0026] According to the technical plan, after the composite slab is hoisted in sections and modules, the post-cast joint treatment can be carried out at the connection of the T-beam flange. It should be noted that during the hoisting of the composite slab, for the hoisting of the composite slab at the T-beam flange, after the T-beam flange is hoisted into place, a post-cast joint is formed at the connection with the composite slab. The reinforcing bars at the post-cast joint are connected by sleeve grouting. The sleeve grouting connection is 100% to ensure that the reinforcing bars at each connection are reliably connected by sleeve grouting. The sleeve grouting connection process is supervised by a dedicated person to ensure the acceptance of concealed works. For the connection nodes of composite beam and composite slab, as well as the connection nodes of T-beam flange and composite beam, fine aggregate concrete of not less than C30 is used for casting and molding, and the vibration and curing of the joint concrete are strengthened.

[0027] Step S8: Installation of flexible weather-resistant sealing strips and high-pressure grouting of concrete:

[0028] Flexible weather-resistant sealing strips are installed between the joints of adjacent composite slabs. These strips serve to seal the joints and resist structural expansion and contraction. Before installation, the limiting steel plates already installed between adjacent composite slabs are removed. Then, the flexible weather-resistant sealing strips are inserted into the joints between adjacent slabs. The thickness of the flexible weather-resistant sealing strip is 2mm to 3mm larger than the width of the joint. Appropriate pressure is applied to force the strips into the joints. After installation, the top surface of the flexible weather-resistant sealing strip should be flush with the top surface of the composite slab. Qi Ping; ensure the proper hoisting of composite slabs and installation of flexible weather-resistant sealing strips in each construction section, and after completing the acceptance of concealed works, high-pressure grouting of concrete can proceed; during the high-pressure grouting construction, the grouting holes on the composite slabs are shaped like "truncated cones" and the overflow holes are shaped like "inverted truncated cones". Under the advance of high-pressure grouting, a smoother grouting process and a more pressurized overflow process are achieved, resulting in a denser grouting effect; the concrete grouting material used is micro-expansion low-shrinkage fine stone concrete grouting material, and the strength of the concrete grouting material should be at least one grade higher than the design concrete strength of the main structure and not lower than C35;

[0029] Step S9: Tensioning and anchoring of unbonded prestressed tendons:

[0030] According to the technical solution, the unbonded prestressed tendons inside the segmented support post-tensioned prestressed precast road structure of the T-beam flange are tensioned and anchored using the post-tensioning method. The spacing between the unbonded prestressed tendons along the longitudinal direction of the road does not exceed 1500mm, and the number of unbonded prestressed tendons is appropriately increased in the post-cast joint area where the T-beam flange connects to the composite slab on both sides. The unbonded prestressed tendons are directly tensioned and anchored on site without the need for grouting. During on-site construction, the tensioning of the unbonded prestressed tendons can only be carried out after the concrete grouting material has been high-pressure injected and cured to 100% of the design strength. Over-tensioning with 1.05σcon is used, and symmetrical tensioning is employed. After the unbonded prestressed tendons are tensioned and anchored, "sulfur mortar waterproof and crack-resistant mortar" is used for sealing the anchors.

[0031] Step S10: Full paving of the asphalt concrete surface layer:

[0032] For the asphalt concrete pavement work, high-quality, high-viscosity modified asphalt and high-strength aggregates are used in the on-site construction. Mixing and production are carried out in a strictly temperature-controlled factory environment to ensure the uniformity and performance stability of the asphalt mixture. According to the technical plan, after all the above-mentioned process segments are completed, process steps S1 to S9 are repeated until all T-beam flange segments are supported and the unbonded prestressed prefabricated road structure is hoisted and installed. The construction is organized in a continuous flow manner. After the completion of all main structure construction, the asphalt concrete pavement can be fully paved. After the paving is completed, the final flatness and elevation of the entire line are checked, and a comprehensive acceptance is organized.

[0033] Compared with the prior art, the beneficial effects of this invention are as follows:

[0034] 1. This invention, through the ingenious combination of "segmented support of T-beam flanges", "post-casting technology system for longitudinal and transverse beams and slabs" and "post-tensioned prestressing", combines dry and wet methods, fundamentally overcoming the defects of traditional wet construction and simple prefabricated road structure design such as insignificant seismic resistance, unclear stress path, and poor structural energy dissipation effect.

[0035] 2. The invention significantly improves the overall structural integrity and load-bearing performance, forming a robust integrated beam-slab structure in both longitudinal and transverse directions. By tightly connecting the T-beam flanges with the segmented composite slabs under the action of post-cast sections and prestressing, the T-beam flanges and composite beams form nodes, and the T-beam flanges and composite slabs form post-cast nodes, thus forming a "cross-composite beam-slab" integrated structure that shares the load in both longitudinal and transverse directions.

[0036] 3. This invention clarifies the force transmission path and stress redundancy. Post-tensioned prestressing establishes active compressive stress in the structure, effectively offsetting the tensile stress caused by vehicle loads and significantly improving the structure's crack resistance. Even if minor damage occurs at local supports or connection points, the presence of prestress ensures that the load is effectively transferred through other paths, providing multiple safety reserves. Simultaneously, it effectively improves the stress state of the bridge deck system, greatly reducing the risk of damage to subsequent pavement layers.

[0037] 4. This invention can adapt to the problem of uneven settlement of structures. The segmented support design allows each support point to adjust its elevation independently within a certain range. When uneven settlement occurs in the foundation, leveling can be achieved by simply adding thin steel plates at the support points, avoiding the secondary internal forces caused by settlement in traditional continuous systems, and demonstrating good adaptability to adverse geological conditions. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the T-beam flange segmented support post-tensioned unbonded prestressed assembled road structure of the present invention;

[0039] Figure 2 This is a plan view of the road structure assembled with segmented support of T-beam flanges and post-tensioned unbonded prestressing according to the present invention.

[0040] Figure 3 This is a schematic diagram of the T-beam flange structure of the present invention;

[0041] Figure 4 This is a flowchart of the construction process of the present invention. Detailed Implementation

[0042] This invention discloses a method for constructing a T-beam flange-supported, post-tensioned, unbonded prestressed road assembly, and a construction method thereof. See reference [link to relevant documentation]. Figures 1 to 3 The structure includes a gravel cushion layer 1, a fine stone concrete layer 2, a composite beam 3, a composite slab 4, a T-beam flange 5, concrete grouting material, unbonded prestressed tendons 61, anchorages 62, and an asphalt concrete surface layer 7. The gravel cushion layer 1 is topped with a fine stone concrete layer 2, and the fine stone concrete layer 2 is topped with a composite beam 3. The top of the composite beam 3 is pre-embedded with positioning steel bars 33, and the composite beam 3 is also provided with pre-reserved through holes. The two ends of the composite slab 4 rest on the top of the composite beam 3, and the ends of the composite slab 4 resting on the top of the composite beam 3 are pre-embedded with perforated connecting steel plates 41. The perforated connecting steel plates 41 are reliably connected to the positioning steel bars 33 pre-embedded on the top of the composite slab 4.

[0043] T-beam flanges 5 are arranged in segments perpendicular to the longitudinal direction of the road. Exposed reinforcing bars are provided at the ends of the T-beam flanges 5, extending into both sides of the road to form post-cast connection nodes with the composite beams 3. These post-cast connection nodes are formed using fine aggregate concrete. A post-cast joint is formed between the T-beam flanges 5 and adjacent composite slabs 4. The exposed reinforcing bars on the sides of the T-beam flanges 5 and composite slabs 4 within the post-cast joint are connected by grouting using reinforcing bar sleeves 8. The composite slab 4 has grouting holes 42 and overflow holes 43 inside. Concrete grout is injected under high pressure into the internal cavity of the structure through the grouting holes 42. Unbonded prestressed tendons 61 are provided between two adjacent composite beams 3 in the transverse direction of the road. The unbonded prestressed tendons 61 pass through pre-reserved holes inside the composite beams 3 at both ends. The unbonded prestressed tendons 61 are fixed to the outer edges of the composite beams 3 using anchors 62. An asphalt concrete surface layer 7 is provided on the upper part of the composite slab 4.

[0044] The new technology system for post-tensioned prestressed prefabricated road construction, with 5-segment support for T-beam wing plates, follows the technical route of "integrated production of prefabricated components, pre-embedded tie bars 31 with additional anchor plates 32 to strengthen the structure, modular assembly of composite beams 3 slabs, longitudinal partitioning of T-beam wing plates 5, sleeve grouting connection design for post-cast joints, frustum-shaped overflow grouting holes 43 to improve grouting density, flexible weather-resistant sealing strips 9 for sealing, high-pressure grouting of micro-expansion, low-shrinkage fine aggregate concrete grouting material, and application of post-tensioned unbonded prestressing tendons 61". It aims to explore efficient application paths and practical solutions for prefabricated technology in road engineering through cutting-edge structural design and process innovation.

[0045] The composite beam 3, composite slab 4, and T-beam flange 5 are all prefabricated in a prefabricated PC factory. The cross-section of the composite beam 3 is not less than 100mm × 150mm, and the prefabricated length of each section of the composite beam 3 does not exceed 6.0m. Positioning reinforcing bars 33 are pre-installed at the top of the composite beam 3 during its prefabrication. The positioning reinforcing bars 33 are located in the middle of the cross-section of the composite beam 3, with a diameter of not less than 20mm. The length of the positioning reinforcing bars 33 embedded inside the composite beam 3 is not less than 1 / 3 of the height of the composite beam 3 and not less than 80mm. The length of the positioning reinforcing bars 33 exposed at the top of the composite beam 3 is not less than 60mm and meets the structural requirements for the connection of the composite beam 3 slab joint. The positioning reinforcing bars 33 are evenly distributed along the length of the composite beam 3, and the spacing between adjacent positioning reinforcing bars 33 does not exceed 200mm. The composite beam 3 also has pre-reserved perforations inside, the positions of which correspond to the positions of the unbonded prestressing tendons 61. The diameter of the pre-reserved perforations is 3mm to 5mm larger than the outer diameter of the unbonded prestressing tendons 61. The composite beam 3 has embedded tie bars 31 at its lower part, with an outward extension length of not less than 300mm and a diameter of not less than 12mm. The pre-reserved tie bars are mainly used to strengthen the connection between the composite beam 3 and the fine aggregate concrete layer 2 inside the structure, and can further enhance the overall load-bearing capacity between the main structure and the lower subbase and roadbed. The embedded tie bars 31 are arranged along the length of the composite beam 3, with a distance between them not exceeding 450mm. An anchor plate 32 is provided at the top of the embedded tie bars 31. The embedded tie bars 31 at the bottom of the composite slab 4 and the end anchor plates 32 both extend into the fine aggregate concrete layer 2 of the road structure.

[0046] The composite slab 4 is internally equipped with grouting holes 42 and overflow holes 43, which are pre-embedded integrally during the prefabrication process of the composite slab 4. To better utilize the performance of the grouting holes 42 and overflow holes 43 within the composite slab 4, thereby improving the density and strength of the concrete grout after grouting, the grouting holes 42 are shaped like a frustum of a cone, and the overflow holes 43 are shaped like an inverted frustum of a cone. This design ensures a relatively smooth grouting process and a relatively pressurized overflow process, thus achieving a better density of the concrete grout. The grouting holes 42 and overflow holes 43 are designed to be of equal size, with a small diameter of 50mm and a large diameter of 80mm. The composite slab 4, supported at the end of the composite beam 3, is provided with a perforated connecting steel plate 41. The perforated connecting steel plate 41 extends continuously along the width of the composite slab 4, extending at least 80mm into the beam-slab connection node. It is anchored into the composite slab 4 for at least 40mm. The diameter of the holes on the perforated connecting steel plate 41 is 2mm larger than the diameter of the top positioning reinforcement 33 of the composite slab 4. The connecting holes on the perforated connecting steel plate 41 correspond one-to-one with the positions of the positioning reinforcement 33, and the positioning reinforcement 33 is inserted into the holes of the perforated connecting steel plate 41 at the end of the composite slab 4, thus achieving a reliable connection between the composite beam 3 and the composite slab 4 at the support end. The connection node between the composite beam 3 and the composite slab 4 is a post-cast node, constructed using fine aggregate concrete with the same strength as the main structural concrete.

[0047] The T-beam flange 5 serves as a crucial load-bearing component for longitudinal separation in the road structure, acting as the starting point for each construction section. The distance between adjacent T-beam flanges 5 does not exceed 70m. The T-beam flange 5, combined with the composite beam 3 and composite slab 4, forms the core technology system of the prefabricated road composite beam 3-slab system. A post-cast joint is provided between the T-beam flange 5 and the adjacent composite slab 4, with a width of not less than 500mm. Within the post-cast joint, steel sleeves 8 connect the exposed steel bars on the side of the T-beam flange 5 and the exposed steel bars on the side of the composite slab 4. The exposed steel bars on the side of the T-beam flange 5 and the composite slab 4 are designed to have the same dimensions and specifications, corresponding one-to-one, and are connected using 100% of the steel sleeves 8 with grouting. The contact surfaces of the T-beam flange 5 and the composite slab 4 at the post-cast joint are roughened to a roughness of not less than 85% to enhance the construction quality after subsequent grouting. The two ends of the T-beam flange 5 form a post-cast connection node with the segmented composite beam 3. The exposed steel bars at the ends of the T-beam flange 5 are longitudinally arranged inside the T-beam flange 5 and extend outward from the ends of the T-beam flange 5. The extension length is not less than 350mm and should meet the anchorage design requirements.

[0048] Unbonded prestressing tendons 61 are laid out in the cavity between the fine aggregate concrete layer 2 and the composite slab 4 according to the road design alignment. Both ends of the unbonded prestressing tendons 61 are anchored to the outer edges of the composite beam 3 using anchors 62. The unbonded prestressing tendons 61 pass through pre-reserved holes inside the composite beam 3 using a perforation method. These pre-reserved holes are made of externally threaded steel pipes and are integrally formed with the composite beam 3 during factory prefabrication. The spacing between the unbonded prestressing tendons 61 is consistent with the pre-reserved holes designed inside the composite beam 3, with a spacing not exceeding 1500mm. The anchors 62 are sealed using "sulfur-impregnated waterproof and crack-resistant mortar". In the post-cast joint area where the T-beam flange 5 connects to the composite slab 4 on both sides, one to two additional unbonded prestressing tendons 61 are added.

[0049] The flexible weather-resistant sealing strip 9 serves as a grouting and leak-sealing structure for the segmented and modular assembly of the composite slab 4. It is applied before the concrete grouting. The flexible weather-resistant sealing strip 9 is placed between the joints of two adjacent composite slabs 4. The length of the flexible weather-resistant sealing strip 9 is 10mm longer than the net distance between the two transverse composite beams 3 of the road. The width of the flexible weather-resistant sealing strip 9 is not less than 30mm, and the thickness is the designed joint width of the composite slab 4 + 3mm. The concrete grouting material is injected into the structure through the grouting holes 42 inside the composite slab 4 using a high-pressure grouting method. Micro-expansion, low-shrinkage fine aggregate concrete grouting material is used, and its strength should be at least one grade higher than the design concrete strength of the main structure and not lower than C35.

[0050] A construction method for a T-beam flange-supported, post-tensioned, unbonded prestressed precast road assembly road adopts the following technical solution: "segmented support of T-beam flanges, hoisting of segmented, modular, and inter-section composite beams and slabs, reinforcement of the load-bearing capacity at the post-cast joint of the T-beam flanges, sealing of the joints between composite slabs with flexible weather-resistant sealing strips, symmetrical post-tensioning of unbonded prestressed concrete, one-time high-pressure grouting, and full paving of the asphalt concrete surface layer." (See reference...) Figure 4 The construction process is as follows: surveying and setting out the road alignment, laying the gravel cushion layer, positioning and hoisting the composite beam, adjusting the embedded tie bars, installing the anchor plate, pouring the fine stone concrete layer, laying the unbonded prestressed tendons, hoisting and positioning the T-beam wing plate, adjusting the exposed reinforcement of the wing plate, hoisting the composite slab in sections and modules, drilling the positioning reinforcement, connecting the reinforcement sleeves at the post-cast joint, pouring the concrete at the joint of the composite beam and slab, installing the flexible weather-resistant sealing strip, high-pressure grouting of the concrete grout, tensioning and anchoring the unbonded prestressed tendons, and laying the asphalt concrete surface layer.

[0051] The specific technical solution for this construction method is as follows:

[0052] Step S1: Measure and lay out the road alignment, and lay the gravel subbase.

[0053] According to the technical plan, the road alignment is first measured in sections using a total station to preliminarily determine the road alignment direction. Obstacles within the road construction area are removed mechanically, and the original roadbed is reinforced. Then, the surface of the roadbed soil layer is properly solidified using the "spraying cement grout method" on the reinforced roadbed. After the cement grout has been left to stand for no less than 6 hours, a sand and gravel cushion layer is laid in sections, and the actual thickness of the sand and gravel cushion layer is no less than 100mm. When laying the sand and gravel cushion layer in sections on site, the construction method of "two-time laying, two-time compaction, and one-time spraying" is adopted. The laying sequence is "crushed stone-coarse sand-crushed stone-coarse sand" in two-time laying sequence. After the two coarse sand layings, mechanical compaction is used. The compaction is completed in two stages. Finally, the surface of the sand and gravel cushion layer is slurried with mixed cement slurry. The cement mortar spraying should be able to fully penetrate the interior of the sand and gravel cushion layer. When the slurry does not sink significantly on the surface of the sand and gravel cushion layer and a small amount of slurry remains on the surface of the sand and gravel cushion layer, it means that the spraying process is qualified. The construction is carried out in sections, and the process is inspected and recorded.

[0054] Step S2: Positioning and hoisting of composite beams

[0055] The composite beams must be prefabricated in the PC factory until they reach 100% of their design strength before being transported to the construction site. During transportation, the positioning reinforcement bars, embedded tie bars, and anchor plates at the ends of the embedded tie bars on the composite beams must be carefully protected. No quality issues should arise due to transportation affecting the appearance quality of the composite beams, severe deformation or breakage of the positioning reinforcement bars or embedded tie bars, or loosening or loss of the anchor plates at the ends of the embedded tie bars. Upon arrival at the site, prefabricated composite beams must be inspected by designated personnel, and only those that pass inspection can be brought to the site. The composite beams will be hoisted onto the top surface of the gravel cushion layer. The placement of the composite beams will be based on the position of the upper reinforcement bars of the two adjacent composite beams in the transverse direction of the road. The distance between the upper reinforcement bars of the two adjacent composite beams in the transverse direction of the road must be strictly controlled to improve the efficiency of subsequent composite slab hoisting and ensure that the maximum deviation of the distance between the upper reinforcement bars of the two adjacent composite beams in the transverse direction of the road is controlled within 3mm. It is important to note that the positional relationship of the composite beams should be properly adjusted by grouting before they are placed on site. In particular, the elevation of the composite beams after hoisting and placement should be controlled based on the elevation of the top surface of the composite beams after placement, with a maximum error controlled within 5mm.

[0056] Step S3: Adjust the pre-embedded tie rods and install the anchor plate.

[0057] According to the technical plan, the positioning reinforcement bars at the top of the composite beam need to be connected to the perforated connecting steel plates on the composite slab through holes in subsequent processes. The pre-embedded tie bars at the bottom of the composite slab need to be anchored into the fine aggregate concrete cushion layer above the sand and gravel cushion layer. After the composite beam is hoisted and positioned in sections, the positioning reinforcement bars at the top of the composite beam and the pre-embedded tie bars at the bottom need to be reasonably adjusted, and the anchor plates at the ends of the pre-embedded tie bars need to be inspected and re-tightened to ensure that each anchor plate is reliably fixed to the pre-embedded tie bar, with 100% of the anchor plates installed. At the same time, in order to effectively coordinate with the pouring of the fine aggregate concrete layer in subsequent processes, after the pre-embedded tie bars and anchor plates are processed, the top surface elevation line of the fine aggregate concrete pouring is projected onto the inner side of the precast composite slab above the pre-embedded tie bars using a chalk line, and the process acceptance work is carried out.

[0058] Step S4: Pour the fine aggregate concrete layer and lay the unbonded prestressed tendons.

[0059] As a crucial component for stabilizing the roadbed, limiting the composite beams, and strengthening the overall structural load-bearing system, the fine aggregate concrete layer can be poured after the pre-embedded tie bars and anchor plates are adjusted. The fine aggregate concrete is poured in sections in a single pour. The elevation of the top surface of the poured fine aggregate concrete is based on the chalk line already marked on the inner side of the precast composite slab above the pre-embedded tie bars, avoiding blind pouring and repeated elevation measurements. The strength grade of the fine aggregate concrete poured on-site is no less than C25. Strengthened vibration and curing improve the compactness and finished product quality of the fine aggregate concrete. Unbonded prestressing tendons can only be laid after the fine aggregate concrete layer has cured to a strength of 1.2 MPa. The unbonded prestressing tendons are laid directly on-site, with both ends passing through the precast composite beam and temporarily anchored to the outer side of the composite beam.

[0060] Step S5: Hoisting and positioning of the T-beam flange, adjusting the exposed reinforcing bars of the flange.

[0061] On-site construction is organized in a continuous flow. After the prestressed tendons are laid in sections, the T-beam flanges can be hoisted and positioned. The T-beam flanges are designed as the starting nodes for adjacent longitudinal construction sections of the prefabricated road. The distance between adjacent T-beam flanges does not exceed 70m. The T-beam flanges, combined with composite beams and composite slabs, form the core technology system of composite beams and slabs for prefabricated roads. Therefore, the on-site T-beam flanges form a reinforced post-cast joint connecting adjacent construction sections in the longitudinal direction of the road, playing a crucial role in improving the overall construction quality of the road. During the on-site hoisting of the T-beam flanges, the positioning elevation of the T-beam flanges can also be adjusted and treated by grouting on the top surface of the fine aggregate concrete. The two ends of the T-beam flanges form post-cast connection nodes with the composite beams, and the exposed reinforcing bars at the ends of the T-beam flanges must be strictly anchored into the post-cast nodes according to the design requirements. After the T-beam flange is hoisted into place, accurately verify the positional relationship and elevation of the T-beam flange, and effectively straighten the exposed reinforcing bars on the sides of the T-beam flange and the composite slab. Assign dedicated personnel to supervise the process. If there are any issues such as improper positioning of the T-beam flange or improper adjustment of the exposed reinforcing bars, remedial measures should be taken, and process acceptance records should be kept.

[0062] Step S6: Segmented and modular hoisting of composite slabs, and positioning of reinforcing bars through holes.

[0063] According to the technical plan, the composite floor slabs are hoisted and supported at the ends of the composite beams for a length of not less than 10mm. The perforated connecting steel plates pre-embedded at the ends of the composite slabs and the positioning reinforcing bars pre-embedded in the upper part of the composite beams are fixed in place using a "mechanical perforation method." The perforated connecting steel plates at the ends of each composite slab and the positioning reinforcing bars pre-embedded in the upper part of the composite beams correspond one-to-one in planar position. The slabs are hoisted sequentially in sections and modules. The composite slabs are hoisted using a four-point horizontal hoisting method, slowly lowered above the road structure, ensuring precise alignment of the holes on the perforated connecting steel plates at the ends of the composite slabs with the protruding positioning reinforcing bars in the upper part of the composite beams. They are then slowly lowered, with steel shims used for fine-tuning the positioning elevation. After all the composite slabs in each construction section are hoisted into place, the perforated connecting steel plates and positioning reinforcing bars are sequentially fixed by welding. During on-site hoisting, a 5mm to 10mm joint is left between adjacent composite slabs. During the hoisting of the composite slabs, steel plates of corresponding size are used to limit the ends to ensure that the joint size between all adjacent composite slabs is equal, so as to facilitate the uniform installation of flexible weather-resistant sealing strips later.

[0064] Step S7: Connect the reinforcing steel sleeves at the post-cast joint and pour the concrete for the composite beam-slab joint.

[0065] According to the technical plan, after the composite slab is hoisted in sections and modules, the post-cast joint treatment can be carried out at the connection of the T-beam flange. It is particularly important to note that during the hoisting of the composite slab, regarding the hoisting of the T-beam flange, after the T-beam flange is hoisted into place, a post-cast joint is formed at the connection with the composite slab. The reinforcing bars at this post-cast joint are connected using sleeve grouting. The sleeve grouting connection is 100% guaranteed, ensuring that the reinforcing bars at each connection are reliably connected using sleeve grouting. A dedicated person will supervise the sleeve grouting process to ensure proper acceptance of the concealed works. For the connection nodes between the composite beam and the composite slab, and the connection nodes between the T-beam flange and the composite beam, fine aggregate concrete of no less than C30 will be used for casting, and the vibration and curing of the concrete at these nodes will be strengthened.

[0066] Step S8: Install flexible weather-resistant sealing strips and inject high-pressure concrete grout.

[0067] Flexible weather-resistant sealing strips are installed between the joints of adjacent composite slabs. These strips serve to seal the joints and resist structural expansion and contraction. Before installing the flexible weather-resistant sealing strips on-site, the limiting steel plates already installed between adjacent composite slabs are removed. Then, the flexible weather-resistant sealing strips are inserted into the joints between adjacent composite slabs. The thickness of the flexible weather-resistant sealing strip should be 2mm to 3mm wider than the joint between adjacent composite slabs. The flexible weather-resistant sealing strips should be pressed into the joints using appropriate pressure. After installation, the top surface of the flexible weather-resistant sealing strip should be flush with the top surface of the composite slab. After ensuring the composite slabs are properly hoisted and the flexible weather-resistant sealing strips are installed in each construction section, and after the concealed works have been inspected and accepted, high-pressure grouting of concrete can begin. During high-pressure grouting of concrete, the grouting holes on the composite slab are shaped like a frustum of a cone, while the overflow holes are shaped like an inverted frustum of a cone. This high-pressure grouting process ensures a smoother grouting flow and increased pressure during overflow, resulting in a denser grout. The concrete grout used is a micro-expansion, low-shrinkage fine-aggregate concrete grout, and its strength should be at least one grade higher than the design strength of the main structure concrete, but not lower than C35.

[0068] Step S9: Tensioning and anchoring of unbonded prestressed tendons

[0069] According to the technical plan, the unbonded prestressed tendons inside the segmented support post-tensioned prestressed precast road structure of the T-beam flange are tensioned and anchored using the post-tensioning method. The spacing between the unbonded prestressed tendons along the longitudinal direction of the road does not exceed 1500mm, and the number of unbonded prestressed tendons is appropriately increased in the post-cast joint area where the T-beam flange connects to the composite slab on both sides. The unbonded prestressed tendons are directly tensioned and anchored on site without the need for grouting. During on-site construction, the tensioning of the unbonded prestressed tendons can only proceed after the concrete grout has been high-pressure injected and cured to 100% of its design strength. Over-tensioning with 1.05σcon is used, and symmetrical tensioning is employed. After tensioning and anchoring, the unbonded prestressed tendons are sealed with "sulfur-impregnated waterproof and crack-resistant mortar".

[0070] Step S10: Full paving of asphalt concrete surface layer

[0071] For the asphalt concrete pavement work, high-quality, high-viscosity modified asphalt and high-strength aggregates are used in on-site construction. Mixing and production are carried out in a strictly temperature-controlled factory environment to ensure the uniformity and performance stability of the asphalt mixture. According to the technical plan, after all the above-mentioned process segments are completed, process steps S1 to S9 are repeated until the hoisting construction of all T-beam flange segments supported by post-tensioned unbonded prestressed prefabricated road structures is completed. A continuous construction organization is adopted, and once all the main structures are completed, the asphalt concrete pavement can be fully laid. After paving is completed, a final check of the flatness and elevation of the entire line is conducted, followed by a comprehensive acceptance inspection.

[0072] In summary, this invention comprehensively considers many problems in the application of current prefabricated construction technology and designs and develops a new technical system in which T-beam wing plates are supported in segments along the longitudinal direction of the road, with their ends forming post-cast connection nodes with the composite beams, and their beam bodies forming post-cast sections with the composite slabs. The main structure forms a new structure, new process, and new method for prefabricated roads with longitudinal and transverse joint load-bearing of "T-beam wing plates - composite beams - composite slabs". The T-beam wing plates are arranged along the longitudinal direction of the road, and their top wing plate surface is the top elevation of the prefabricated road structure. The hoisting and positioning of the T-beam wing plates provides a clear elevation for the entire prefabricated road construction. The navigation system and the T-beam wing plate divide the entire road structure into several construction sections, each of which forms several modules. Each section and module can be independently hoisted, positioned, and grouted, which also facilitates the organization of continuous construction. The T-beam wing plate can also be used to separate adjacent sections and serve as a partition formwork. Each section can be operated directly without the need to set up baffles during segmented construction. This also effectively solves the technical problems that occur in the application of traditional prefabricated construction technology, such as road collapse, uneven road surface difference, and poor overall seismic resistance due to uneven foundation settlement and large vibration at the construction section.

[0073] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A T-beam flange segmented support post-tensioned unbonded prestressed assembled road, characterized in that: It includes a sand and gravel cushion layer, a fine stone concrete layer, a composite beam, a composite slab, a T-beam flange, concrete grouting material, and unbonded prestressed tendons. A fine stone concrete layer is provided on top of the sand and gravel cushion layer. Composite beams are provided at both ends of the fine stone concrete layer. Positioning steel bars are pre-embedded in the top of the composite beams. There are also reserved through holes inside the composite beams. The two ends of the composite slab rest on the top of the composite beams. Perforated connecting steel plates are pre-embedded at the ends of the composite slabs resting on the top of the composite beams. The perforated connecting steel plates are reliably connected to the positioning steel bars pre-embedded in the top of the composite slabs. The T-beam flanges are arranged in segments perpendicular to the longitudinal direction of the road. The ends of the T-beam flanges are provided with exposed steel bars, which extend into both sides of the road to form post-cast connection nodes with the composite beams. The post-cast connection nodes are formed by casting fine aggregate concrete. A post-cast joint is formed between the T-beam flanges and the adjacent composite slabs. The exposed steel bars on the sides of the T-beam flanges and the composite slabs in the post-cast joint are connected by grouting with steel bar sleeves. The composite slab is equipped with grouting holes and overflow holes. The concrete grout is injected into the internal cavity of the structure under high pressure through the grouting holes. Unbonded prestressed tendons are provided between two adjacent composite beams in the transverse direction of the road. The two ends of the unbonded prestressed tendons pass through the reserved holes inside the composite beam. The unbonded prestressed tendons are fixed to the outer edge of the composite beam by anchors. The upper part of the composite slab is covered with an asphalt concrete surface layer.

2. The assembly road according to claim 1, characterized in that: The composite beams, composite slabs, and T-beam flanges are all prefabricated in a prefabricated PC factory. The cross-section of the composite beam is not less than 100mm × 150mm, and the prefabricated length of each composite beam segment does not exceed 6.0m. The positioning reinforcement at the top of the composite beam is located in the middle of the composite beam cross-section. The diameter of the positioning reinforcement is not less than 20mm, the length of the positioning reinforcement embedded inside the composite beam is not less than 1 / 3 of the height of the composite beam and not less than 80mm, and the length of the positioning reinforcement exposed at the top of the composite beam is not less than 60mm. The positioning reinforcement is evenly distributed along the length of the composite beam, and the spacing between adjacent positioning reinforcements does not exceed 200mm. The reserved perforation positions inside the composite beam correspond to the positions of the unbonded prestressing tendons. The diameter of the reserved perforation is 3mm to 5mm larger than the outer diameter of the unbonded prestressing tendons. The reserved perforation uses externally threaded steel pipes and is completed as an integral part with the prefabrication of the composite beam PC in the factory. The lower part of the composite beam is equipped with embedded tie bars. The extended length of the embedded tie bars is not less than 300mm and the diameter is not less than 12mm. The embedded tie bars are arranged along the length of the composite beam, and the distance between the embedded tie bars does not exceed 450mm. The top of the embedded tie bars is equipped with an anchor plate. The embedded tie bars at the bottom of the composite beam and the end anchor plates extend into the fine stone concrete layer of the road structure.

3. The assembly road according to claim 1, characterized in that: The composite slab is equipped with grouting holes and overflow holes, which are pre-embedded as an integrated unit during the prefabrication process. The grouting holes are shaped like a frustum of a cone, and the overflow holes are shaped like an inverted frustum of a cone. The grouting holes and overflow holes are designed to be of equal size, with a small diameter of 50mm and a large diameter of 80mm. A perforated connecting steel plate is located at the end of the composite slab where it is supported by the composite beam. It extends along the width of the composite slab and extends into the beam-slab connection node with a width of not less than 80mm. The perforated connecting steel plate is anchored into the composite slab for not less than 40mm. The diameter of the hole on the perforated connecting steel plate is 2mm larger than the diameter of the top positioning reinforcement bar of the composite slab. The connecting holes on the perforated connecting steel plate correspond one-to-one with the positions of the positioning reinforcement bars, and the positioning reinforcement bars are inserted into the holes of the perforated connecting steel plate. The connection node between the composite beam and the composite slab is a post-cast node, which is cast using fine aggregate concrete with the same strength as the main structure concrete.

4. The assembly road according to claim 1, characterized in that: The T-beam flange is the starting node of each construction section. The distance between adjacent T-beam flanges shall not exceed 70m. The width of the post-cast joint between the T-beam flange and the adjacent composite slab shall not be less than 500mm. The exposed steel bars on the side of the T-beam flange and the exposed steel bars on the side of the composite slab shall be the same in size and specification, corresponding one-to-one, and connected by 100% quantity steel bar sleeve grouting. The contact surface between the T-beam flange and the composite slab at the post-cast joint shall be roughened, with a roughness of not less than 85%. The exposed steel bars at the beam end of the T-beam flange and the segmented composite beam shall form a post-cast connection node. The exposed steel bars shall be longitudinally arranged inside the T-beam flange and extend outward to its end, with an outward extension length of not less than 350mm.

5. The assembly road according to claim 1, characterized in that: Unbonded prestressing tendons are placed in the cavity between the fine aggregate concrete layer and the composite slab. The unbonded prestressing tendons pass through the pre-reserved holes inside the composite beam using the perforation method. The spacing between the unbonded prestressing tendons is consistent with the pre-reserved holes designed inside the composite beam, and the spacing does not exceed 1500mm. The anchorage is sealed with "sulfur mortar waterproof and crack-resistant mortar". In the post-cast joint area where the T-beam flange connects to the composite slab on both sides, 1 to 2 more unbonded prestressing tendons are added.

6. The assembly road according to claim 1, characterized in that: It also includes flexible weather-resistant sealing strips, which are installed between the joints of two adjacent composite slabs. The length of the flexible weather-resistant sealing strip is 10mm longer than the net distance between the two transverse composite beams of the road. The width of the flexible weather-resistant sealing strip is not less than 30mm, and the thickness is the design width of the composite slab joint + 3mm. The concrete grout is injected into the structure through the grouting holes inside the composite slab using a high-pressure grouting method. Micro-expansion, low-shrinkage fine stone concrete grout is used. The strength of the concrete grout should be at least one grade higher than the design concrete strength of the main structure and not lower than C35.

7. A construction method for a T-beam flange segmented support post-tensioned unbonded prestressed assembled road, characterized by: The construction process is as follows: surveying and setting out the road alignment, laying the gravel cushion layer, positioning and hoisting the composite beam, adjusting the embedded tie bars, installing the anchor plate, pouring the fine stone concrete layer, laying the unbonded prestressed tendons, hoisting and positioning the T-beam wing plate, adjusting the exposed reinforcement of the wing plate, hoisting the composite slab in sections and modules, drilling the positioning reinforcement, connecting the reinforcement sleeves at the post-cast joint, pouring the concrete at the joint of the composite beam and slab, installing the flexible weather-resistant sealing strip, high-pressure grouting of the concrete grout, tensioning and anchoring the unbonded prestressed tendons, and laying the asphalt concrete surface layer.

8. The construction method according to claim 7, characterized in that: The specific technical solution is as follows: Step S1: Measure and lay out the road alignment, and lay the gravel subbase: According to the technical plan, the road alignment will first be surveyed in sections using a total station to preliminarily determine the road's direction. Obstacles within the road construction area will be removed mechanically, and the original roadbed will be reinforced. Then, the surface of the roadbed soil will be appropriately solidified using a "sprayed cement grout" method. After the cement grout has been left to stand for at least 6 hours, a sand and gravel cushion layer will be laid in sections, with a minimum actual thickness of 100mm. During the on-site section laying of the sand and gravel cushion layer, a method of "two-stage paving, two-stage compaction, and one-stage spraying" will be adopted. The construction of the sand and gravel cushion layer is carried out in a two-stage laying sequence of "crushed stone - coarse sand - crushed stone - coarse sand". After the two layers of coarse sand are laid, they are compacted by machinery. The compaction is completed in two stages. Finally, the surface of the sand and gravel cushion layer is slurry mixed with cement. The cement mortar spraying should be able to fully penetrate the sand and gravel cushion layer. When the slurry does not sink significantly on the surface of the sand and gravel cushion layer and a small amount of slurry remains on the surface of the sand and gravel cushion layer, it means that the spraying process is qualified. The construction is carried out in sections, and the process is inspected and recorded. Step S2: Positioning and hoisting of composite beams: The composite beams must be prefabricated in the PC factory until they reach 100% of their design strength before being transported to the construction site. During transportation, the positioning reinforcement bars, embedded tie bars, and anchor plates at the ends of the embedded tie bars on the composite beams must be carefully protected. No quality issues should arise due to transportation affecting the appearance quality of the composite beams, severe deformation or breakage of the positioning reinforcement bars or embedded tie bars, or loosening or loss of the anchor plates at the ends of the embedded tie bars. Upon arrival at the site, prefabricated composite beams must be inspected by designated personnel; only those that pass inspection can be brought to the site. The on-site hoisting of the composite beams will be located on the top surface of the sand and gravel cushion layer. The placement of the composite beams is based on the position of the upper reinforcing bars of the two adjacent crossbeams. Strict control must be exercised over the distance between these upper reinforcing bars to improve efficiency for subsequent composite slab hoisting and ensure the maximum deviation of the distance between the upper reinforcing bars of the two adjacent crossbeams is within 3mm. It is important to note that the positional relationship of the composite beams should be properly adjusted using grouting before on-site placement, especially the elevation after hoisting. The elevation should be controlled based on the top surface elevation of the placed composite beams, with a maximum error within 5mm. Step S3: Adjust the pre-embedded tie rods and install the anchor plate: According to the technical plan, the positioning steel bars at the top of the composite beam need to be connected to the perforated connecting steel plates on the composite slab through holes in the subsequent process. The pre-embedded tie bars at the bottom of the composite slab need to be anchored into the fine stone concrete cushion layer above the sand and gravel cushion layer. After the composite beam is hoisted and positioned in sections, the positioning steel bars at the top of the composite beam and the pre-embedded tie bars at the bottom need to be reasonably adjusted, and the anchor plates at the ends of the pre-embedded tie bars need to be inspected and re-tightened to ensure that each anchor plate is reliably fixed to the pre-embedded tie bar, and 100% of the anchor plates are installed. At the same time, in order to effectively cooperate with the pouring of the fine stone concrete layer in the subsequent process, after the pre-embedded tie bars and anchor plates are processed, the top surface elevation line of the fine stone concrete pouring is projected onto the inner side of the precast composite slab above the pre-embedded tie bars using a chalk line, and the process acceptance work is carried out. Step S4: Pouring of fine aggregate concrete layer and laying of unbonded prestressed tendons: As a crucial component for stabilizing the roadbed, limiting the composite beams, and strengthening the overall structural load-bearing system, the fine aggregate concrete layer can be poured after the pre-embedded tie bars and anchor plates are adjusted. The fine aggregate concrete is poured in sections in a single pour. The elevation of the top surface of the fine aggregate concrete is based on the chalk line already marked on the inner side of the precast composite slab above the pre-embedded tie bars, avoiding blind pouring and repeated elevation measurements. The strength grade of the fine aggregate concrete poured on-site is not lower than C25. Vibration and curing are strengthened to improve the compactness and finished product quality of the fine aggregate concrete. Unbonded prestressing tendons can only be laid after the fine aggregate concrete layer has cured to a strength of 1.2 MPa. The unbonded prestressing tendons are laid directly on-site, with both ends of the unbonded prestressing tendons passing through the precast composite beams and temporarily anchored to the outer side of the composite beams. Step S5: Hoisting and positioning of the T-beam flange, and adjusting the exposed reinforcing bars on the flange: On-site construction was organized in a continuous flow. After the prestressed tendons were laid in sections, the T-beam flanges could be hoisted and positioned. The T-beam flanges were designed as the starting nodes for adjacent longitudinal construction sections of the prefabricated road, with a distance of no more than 70m between adjacent T-beam flanges. The T-beam flanges, combined with composite beams and composite slabs, formed the core technology system of composite beams and slabs for prefabricated roads. Therefore, the on-site T-beam flanges formed a reinforced post-cast joint connecting adjacent construction sections in the longitudinal direction of the road, playing a crucial role in improving the overall construction quality of the road. During the on-site hoisting of the T-beam flanges, in the fine aggregate concrete... The T-beam flange elevation can also be adjusted and treated by grouting on the concrete top surface. The two ends of the T-beam flange form a post-cast connection node with the composite beam. The exposed steel bars at the ends of the T-beam flange must be strictly anchored into the post-cast node according to the design requirements. After the T-beam flange is hoisted into place, the positional relationship and elevation of the T-beam flange should be accurately checked, and the exposed steel bars on the sides of the T-beam flange and the composite slab should be effectively straightened. A dedicated person should be assigned to supervise the process. If the T-beam flange is not positioned properly or the exposed steel bars are not adjusted properly, remedial measures should be taken, and process acceptance records should be kept. Step S6: Segmented and modular hoisting of the composite slab, positioning and drilling of reinforcing bars: According to the technical solution, the composite floor slabs are hoisted and supported at the ends of the composite beams for a length of not less than 10mm. The perforated connecting steel plates pre-embedded at the ends of the composite slabs and the positioning reinforcing bars pre-embedded in the upper part of the composite beams are fixed in place using a "mechanical perforation method." The perforated connecting steel plates at the ends of each composite slab and the positioning reinforcing bars pre-embedded in the upper part of the composite beams correspond one-to-one in planar position. The slabs are hoisted sequentially in sections and modules. The composite slabs are hoisted using a four-point horizontal lifting method, slowly lowered above the road structure, allowing the perforated connecting steel plates at the ends of the composite slabs to be properly positioned. The orifice on the beam is precisely aligned with the positioning reinforcement bars extending outward from the top of the composite beam. The beam is then slowly lowered, and steel shims are used to fine-tune the positioning elevation of both. After all the composite slabs in each construction section are hoisted into place, the perforated connecting steel plates and positioning reinforcement bars are spot-welded and fixed one by one using the welding method. During the on-site hoisting process, a 5mm to 10mm joint is left between adjacent composite slabs. During the hoisting of the composite slabs, steel plates of corresponding size are used to limit the ends to ensure that the joint size between all adjacent composite slabs is equal, so as to facilitate the uniform installation of the flexible weather-resistant sealing strips later. Step S7: Post-cast reinforcement sleeve connection at the joint, concrete pouring for the composite beam-slab joint: According to the technical plan, after the composite slab is hoisted in sections and modules, the post-cast joint treatment can be carried out at the connection of the T-beam flange. It should be noted that during the hoisting of the composite slab, for the hoisting of the composite slab at the T-beam flange, after the T-beam flange is hoisted into place, a post-cast joint is formed at the connection with the composite slab. The reinforcing bars at the post-cast joint are connected by sleeve grouting. The sleeve grouting connection is 100% to ensure that the reinforcing bars at each connection are reliably connected by sleeve grouting. The sleeve grouting connection process is supervised by a dedicated person to ensure the acceptance of concealed works. For the connection nodes of composite beam and composite slab, as well as the connection nodes of T-beam flange and composite beam, fine aggregate concrete of not less than C30 is used for casting and molding, and the vibration and curing of the joint concrete are strengthened. Step S8: Installation of flexible weather-resistant sealing strips and high-pressure grouting of concrete: Flexible weather-resistant sealing strips are installed between the joints of adjacent composite slabs. These strips serve to seal the joints and resist structural expansion and contraction. Before installation, the limiting steel plates already installed between adjacent composite slabs are removed. Then, the flexible weather-resistant sealing strips are inserted into the joints between adjacent slabs. The thickness of the flexible weather-resistant sealing strip is 2mm to 3mm wider than the joint width. Appropriate pressure is applied to force the strip into the joint. After installation, the top surface of the flexible weather-resistant sealing strip should be flush with the top surface of the composite slab. Qi Ping; ensure that the composite slabs in each construction section are properly hoisted and the flexible weather-resistant sealing strips are properly installed, and after the concealed works are inspected and accepted, high-pressure grouting of concrete can be carried out; during the high-pressure grouting construction, the grouting holes on the composite slabs are shaped like "truncated cones" and the overflow holes are shaped like "inverted truncated cones". Under the advance of high-pressure grouting, the grouting process is smoother and the overflow process is more pressurized, resulting in a denser grouting effect; the concrete grouting material used is micro-expansion low-shrinkage fine stone concrete grouting material, and the strength of the concrete grouting material should be at least one grade higher than the design concrete strength of the main structure and not lower than C35; Step S9: Tensioning and anchoring of unbonded prestressed tendons: According to the technical plan, the unbonded prestressed tendons inside the segmented support post-tensioned prestressed precast road structure of the T-beam flange are tensioned and anchored using the post-tensioning method. The spacing between the unbonded prestressed tendons along the longitudinal direction of the road does not exceed 1500mm, and the number of unbonded prestressed tendons is appropriately increased in the post-cast joint area where the T-beam flange connects to the composite slab on both sides. The unbonded prestressed tendons are directly tensioned and anchored on site without the need for grouting in the ducts. During on-site construction, the tensioning of the unbonded prestressed tendons can only be carried out after the concrete grout has been cured to 100% of its design strength after high-pressure grouting. Over-tensioning with 1.05σcon is used, and symmetrical tensioning is employed. After the unbonded prestressed tendons are tensioned and anchored, "sulfur mortar waterproof and crack-resistant mortar" is used for sealing and anchoring. Step S10: Full paving of the asphalt concrete surface layer: For the asphalt concrete pavement work, high-quality, high-viscosity modified asphalt and high-strength aggregates are used in the on-site construction. Mixing and production are carried out in a strictly temperature-controlled factory environment to ensure the uniformity and performance stability of the asphalt mixture. According to the technical plan, after all the above-mentioned process segments are completed, process steps S1 to S9 are repeated until all T-beam flange segments are supported and the unbonded prestressed prefabricated road structure is hoisted and installed. The construction is organized in a continuous flow manner. After the completion of all main structure construction, the asphalt concrete pavement can be fully paved. After the paving is completed, the final flatness and elevation of the entire line are checked, and a comprehensive acceptance is organized.

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