A prefabricated orthotropic steel-rubber ECC composite bridge deck and its construction method

Abstract

This invention discloses a prefabricated orthotropic steel-rubber ECC composite bridge deck and its construction method. The composite bridge deck includes prefabricated rubber ECC unit panels and a top plate. An epoxy resin adhesive layer is provided between the prefabricated rubber ECC unit panels and the top plate. Several shear grooves are provided within the prefabricated rubber ECC unit panels for inserting clustered stud connectors. The clustered stud connectors are welded to the top plate at intervals, avoiding fatigue-sensitive areas. The prefabricated rubber ECC unit panels are connected through prefabricated panel joint connection areas. The construction method includes: setting shear grooves, prefabricating rubber ECC unit panels, welding clustered stud connectors to the top plate to form an epoxy resin adhesive layer; hoisting the prefabricated rubber ECC unit panels so that the clustered stud connectors extend into the shear grooves; and pouring and curing. This invention can significantly improve the local stiffness of the bridge deck, improve wheel load diffusion and stress redistribution, reduce the stress amplitude of fatigue-prone parts, and improve fatigue performance.

Description

Technical Field

[0001] This invention pertains to composite bridge decks and their construction methods, specifically a prefabricated orthotropic steel-rubber ECC composite bridge deck and its construction method. Background Technology

[0002] Orthotropic steel bridge decks mainly consist of a top plate, longitudinal ribs, and transverse diaphragms. They offer advantages such as lightweight and high strength, rapid construction, and wide applicability, and are widely used in medium-span steel box girder or steel-concrete composite girder bridges, large-span steel truss bridges, large-span or ultra-large-span cable-stayed bridges, and suspension bridges. Furthermore, to improve driving safety and comfort and reduce the direct impact of the external environment on the steel bridge deck, an asphalt concrete pavement layer is laid on the top plate of the steel bridge deck. This pavement layer is connected to the steel top plate as a whole using adhesive materials. However, under the coupled effects of vehicle fatigue loads and complex environmental conditions, this bridge deck system is prone to defects such as asphalt concrete pavement layer damage and peeling, fatigue cracking of welded details in the steel bridge deck, water leakage, and corrosion of the steel bridge deck. These issues have become key technical bottlenecks restricting the safety and durability of orthotropic steel bridge decks.

[0003] To address the persistent problems of fatigue cracking and pavement delamination in orthotropic steel bridge decks, laying a concrete structural layer on the steel bridge deck and using shear connectors to achieve synergistic stress distribution can significantly improve the deck stiffness, enhance wheel load diffusion and stress redistribution, thereby reducing stress amplitude in fatigue-prone areas and improving the fatigue performance of the bridge deck. This is one of the effective ways to alleviate the aforementioned problems. However, traditional steel-concrete composite bridge decks still have the following issues in practical applications:

[0004] (1) The concrete structure layer is thick, which increases the self-weight and limits the applicability of long-span bridges.

[0005] (2) On-site construction quality is difficult to guarantee. Large-area concrete pouring is easily affected by temperature and humidity environment, construction organization and curing conditions, construction period is long and traffic interference is great.

[0006] (3) Composite bridge decks often use distributed group stud welding as a shear connection method, which adds a large number of welding points to the top plate. Especially when the studs are arranged close to fatigue-sensitive parts such as longitudinal rib-top plate weld, transverse diaphragm-top plate weld, and longitudinal rib-top plate-transverse diaphragm three-way cross weld, new fatigue risks are easily triggered.

[0007] (4) Ordinary concrete has low tensile strength and is brittle and prone to cracking. It is easy to form through cracks in the stiffness abrupt change and tension zone. Once through cracks are formed, corrosive media such as water and chloride salts will aggravate the damage and deterioration of the steel bridge deck, and the long-term durability of the bridge deck is still in danger.

[0008] (5) The bridge deck pavement layer needs to be inspected regularly and repaired or replaced in a timely manner. For steel-concrete composite bridge decks with distributed stud group connections, when the local structural layer is damaged or its performance deteriorates, it is difficult to remove the concrete layer and treat the interface, resulting in low construction efficiency, significant traffic interference, and affecting the repair quality and subsequent maintainability.

[0009] In summary, existing orthotropic steel bridge decks suffer from high fatigue cracking risk, insufficient durability of traditional pavement layers, long construction cycles for cast-in-place composite bridge deck systems, and difficulties in later maintenance. There is an urgent need for a composite bridge deck structure that can reduce the number of new weld points and avoid fatigue-sensitive areas while ensuring efficient shear force transfer at the interface, and simultaneously achieve prefabricated assembly construction and convenient later maintenance. Summary of the Invention

[0010] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a prefabricated orthotropic steel-rubber ECC composite bridge deck with excellent fatigue resistance and good durability. Another purpose of this invention is to provide a construction method for a prefabricated orthotropic steel-rubber ECC composite bridge deck that has high construction efficiency and can be quickly repaired and replaced.

[0011] Technical Solution: The present invention discloses an assembled orthotropic steel-rubber ECC composite bridge deck, comprising prefabricated rubber ECC unit plates and a top plate. An epoxy resin bonding layer is provided between the prefabricated rubber ECC unit plates and the top plate. Several shear grooves for inserting clustered stud connectors are provided in the prefabricated rubber ECC unit plates. The shear grooves are filled with rubber ECC material with shrinkage compensation function, which wraps the clustered stud connectors and forms a shear groove grouting connection area. The clustered stud connectors are welded to the top plate at intervals, avoiding fatigue-sensitive areas. The prefabricated rubber ECC unit plates are connected through the prefabricated plate splice connection area.

[0012] Furthermore, the clustered stud connector includes multiple studs, which are arranged at intervals in the longitudinal and transverse directions, with the spacing determined according to the interface shear force transfer requirements between the precast rubber ECC unit plate and the top plate.

[0013] Furthermore, the studs are anchoring-reinforced studs, arranged in a rectangular or linear pattern. The anchoring-reinforced studs include an anchoring reinforcement part and a stud rod. The anchoring reinforcement part is one or more of the following: a threaded section, a circumferential rib, or a dotted protrusion. The anchoring reinforcement part forms a mechanical engagement with the shrinkage-compensating rubber ECC material in the shear groove grouting connection area.

[0014] Furthermore, the rubber ECC material with shrinkage compensation function includes cement-based cementitious material, fine aggregate, waste tire rubber particles, chopped fibers, expansion component, shrinkage reduction component, water-reducing agent, and water. Based on the total mass of the solid components of the rubber ECC material with shrinkage compensation function, the cement-based cementitious material accounts for 45%-75%, the fine aggregate for 10%-35%, the rubber particles for 5%-15%, the chopped fibers for 0.5%-3%, the expansion component for 2%-10%, the shrinkage reduction component for 0.1%-2%, and the water-reducing agent for 0.1%-2%, making it a high-toughness material with strain hardening and multi-crack characteristics.

[0015] Furthermore, the shear groove is stepped, and the reserved position of the shear groove on the prefabricated rubber ECC unit plate is determined according to the position of the clustered stud connector, and forms a mechanical interlock with the rubber ECC material with shrinkage compensation function filled therein.

[0016] Furthermore, structural steel bars are installed in the shear groove grouting connection area, and the structural steel bars are connected to the pre-embedded steel bars in the precast rubber ECC unit plate by lap splicing, binding or welding.

[0017] Furthermore, the precast slab joint connection area includes stepped joints and U-shaped reinforcing bars. After the reinforcing bars are inserted, rubber ECC material with shrinkage compensation function is poured to achieve the connection between adjacent precast rubber ECC unit slabs. The rubber ECC material with shrinkage compensation function undergoes restricted micro-expansion during the hardening process, and forms a dense connection with the shear groove sidewall, the edge of the precast rubber ECC unit slab, and the bundled stud connectors.

[0018] Furthermore, longitudinal ribs are provided on the side of the top plate away from the precast rubber ECC unit plate, and the longitudinal ribs are welded and fixed to the top plate and the transverse diaphragm.

[0019] Furthermore, the longitudinal ribs are one or more of the following: U-ribs, plate ribs, closed ribs, or open ribs.

[0020] The construction method for the prefabricated orthotropic steel-rubber ECC composite bridge deck of the present invention includes the following steps:

[0021] Step 1: Identify the welds or existing fatigue crack areas of the orthotropic steel bridge deck, and determine the arrangement of the clustered stud connectors on the top plate according to the interface shear force transfer requirements of the composite bridge deck.

[0022] Step 2: Set shear grooves at corresponding positions on the prefabricated rubber ECC unit plate and prefabricate the prefabricated rubber ECC unit plate;

[0023] Step 3: Remove rust, grind or sandblast the upper surface of the top plate;

[0024] Step 4: Weld the clustered stud connectors to the top plate at the positions determined in Step 1;

[0025] Step 5: Remove welding slag and spatter, and perform a second cleaning of the top plate surface;

[0026] Step 6: Apply epoxy resin adhesive to the upper surface of the top plate to form an epoxy resin adhesive layer;

[0027] Step 7: Hoist and position the prefabricated rubber ECC unit plate so that the clustered stud connectors extend into the corresponding shear grooves;

[0028] Step 8: Pour rubber ECC material with shrinkage compensation function into the joint area of ​​the precast slabs between adjacent precast rubber ECC unit slabs after shear groove and reinforcement bar insertion.

[0029] Step nine involves curing the shear groove grouting connection area and the precast slab splice connection area to form an assembled orthotropic steel-rubber ECC composite bridge deck.

[0030] Furthermore, it also includes step ten, which involves setting an asphalt wear layer on top of the precast rubber ECC unit plate.

[0031] Furthermore, in step one, the weld seams include longitudinal rib-top plate weld seams, transverse diaphragm-top plate weld seams, and longitudinal rib-top plate-transverse diaphragm three-way intersecting weld seams.

[0032] Working Principle: Compared with existing steel bridge deck pavement structures, this invention, based on the shear force transfer requirements of orthotropic steel bridge deck interfaces and the location of fatigue-sensitive areas, groups multiple studs within the same shear groove. A grouting connection zone, encasing the studs and mechanically interlocking, is formed by post-casting shrinkage-compensating rubber ECC material into the shear groove. This ensures shear force transfer at the interface while reducing distributed weld points and avoiding fatigue-sensitive details. Compared with cast-in-place UHPC composite bridge decks, this invention uses precast rubber ECC unit plates and a post-cast rubber ECC connection zone with shrinkage compensation function. This creates a high-toughness, continuous connection system between the precast plates, the shear groove grouting zone, and the joint connection zone, which improves crack resistance, durability, and construction efficiency.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0034] 1. By introducing a precast rubber ECC unit plate structural layer and an orthotropic steel bridge deck to form a combined stress-bearing structure, the local stiffness of the bridge deck can be significantly improved, the wheel load diffusion and stress redistribution can be improved, the stress amplitude of fatigue-prone parts can be reduced, and the fatigue performance can be improved.

[0035] 2. By using clustered stud connections and avoiding fatigue-sensitive areas, the number of new weld points is reduced while ensuring shear force transmission and combined effects, thereby lowering the risk of new fatigue damage.

[0036] 3. Rubber ECC has strain hardening and multi-crack characteristics, which can disperse cracks and control crack width in the negative bending moment tension zone and wheel load zone, reduce the risk of environmental erosion, and improve the long-term service performance of composite bridge deck structure.

[0037] 4. The use of prefabricated rubber ECC unit panels for assembly and shear groove grouting connection can significantly reduce on-site wet work and avoid high-standard maintenance, thereby improving the construction efficiency of the bridge deck. At the same time, the standardized unitized structure provides conditions for rapid repair and partial replacement of damaged parts during operation, reducing the cost of life-cycle maintenance and traffic disruption. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the connection of the epoxy resin adhesive layer 3 of the present invention;

[0040] Figure 3 This is a schematic diagram of the structure of the anchoring reinforcement stud of the present invention, wherein (a) is a threaded type, (b) is a circumferential rib type, and (c) is a dotted protrusion type;

[0041] Figure 4 This is a partial enlarged view of the shear groove grouting connection area 6 of the present invention;

[0042] Figure 5 This is a partial enlarged view of the prefabricated panel splicing area 7 of the present invention;

[0043] Figure 6 This is a schematic diagram of the construction process of the present invention. Detailed Implementation

[0044] like Figures 1-2The prefabricated orthotropic steel-rubber ECC composite bridge deck includes: an orthotropic steel bridge deck, comprising a top plate 2, longitudinal ribs 8, and transverse diaphragms 9; multiple prefabricated rubber ECC unit plates 1, laid on top of the top plate 2 of the orthotropic steel bridge deck; an epoxy resin adhesive layer 3, disposed between the prefabricated rubber ECC unit plates 1 and the top plate 2; and clustered stud connectors 4, welded to a local portion above the top plate 2. The clustered stud connectors 4 consist of multiple studs arranged in groups within the same shear groove 5, and are locally positioned according to the interface shear force transfer requirements of the composite bridge deck and the location of fatigue-sensitive areas of the orthotropic steel bridge deck. The spacing of the studs is determined according to the interface shear force transfer requirements between the prefabricated rubber ECC unit plates 1 and the top plate 2, and avoids the fatigue-sensitive areas of the longitudinal rib-top plate weld, the transverse diaphragm-top plate weld, and the three-way intersecting welds of the longitudinal rib-top plate-transverse diaphragm. Shear groove 5 is set within the precast rubber ECC unit plate 1 and allows the clustered stud connector 4 to extend into it. Shear groove grouting connection area 6 is formed by rubber ECC material with shrinkage compensation function filled within the shear groove 5 and encloses the clustered stud connector 4. Precast slab joint connection area 7 is set between two adjacent precast rubber ECC unit plates 1. Multiple precast rubber ECC unit plates 1 are connected through the precast slab joint connection area 7. The precast rubber ECC unit plates 1 and the orthotropic steel bridge deck are connected as a whole by the epoxy resin adhesive layer 3, the clustered stud connector 4, the shear groove 5, and the shear groove grouting connection area 6, forming a composite bridge deck structure that shares the load. The shrinkage-compensating rubber ECC material comprises cementitious material, fine aggregate, waste tire rubber granules, chopped fibers, expansion component, shrinkage-reducing component, water-reducing agent, and water. Based on the total mass of the solid components of the shrinkage-compensating rubber ECC material, the cementitious material accounts for 45%-75%, the fine aggregate for 10%-35%, the rubber granules for 5%-15%, the chopped fibers for 0.5%-3%, the expansion component for 2%-10%, the shrinkage-reducing component for 0.1%-2%, and the water-reducing agent for 0.1%-2%.

[0045] The longitudinal ribs 8 are one or more of U-ribs, plate ribs, closed ribs, or open ribs, welded to the underside of the top plate 2. Transverse diaphragms 9 are arranged at intervals along the longitudinal direction of the bridge and welded to the top plate 2 and longitudinal ribs 8. The precast rubber ECC unit panels 1 are precast from rubber ECC material, which includes cement-based cementitious materials, chopped fibers, fine aggregates, and waste tire rubber granules. This material is a high-toughness material exhibiting strain hardening and multi-crack characteristics. The precast rubber ECC unit panels 1 can be designed in sections according to bridge deck width, transportation conditions, lifting capacity, and subsequent maintenance requirements. The clustered stud connectors 4 include at least two studs arranged in a rectangular or linear pattern. Multiple clustered stud connectors 4 are arranged at intervals along the longitudinal and transverse directions of the bridge.

[0046] like Figure 3As shown, the studs in the clustered stud connector 4 are anchor-reinforced studs. The anchor-reinforced studs have an anchor reinforcement part on the stud rod. The anchor reinforcement part is one or more of the following: threaded section, circumferential rib, and dot-shaped protrusion. The anchor reinforcement part forms a mechanical engagement with the rubber ECC material with shrinkage compensation function in the shear groove grouting connection area 6.

[0047] When arranging the clustered stud connectors 4 for welding, fatigue-sensitive areas such as longitudinal rib-top plate welds, transverse diaphragm-top plate welds, and three-way intersecting welds of longitudinal rib-top plate-transverse diaphragm should be avoided while meeting the requirements for interface shear force transmission.

[0048] The shear groove 5 is stepped. The reserved position of the shear groove 5 on the prefabricated rubber ECC unit plate 1 is determined according to the position of the clustered stud connector 4, and forms a mechanical interlock with the rubber ECC material with shrinkage compensation function filled in it.

[0049] The post-cast material in the shear groove grouting connection zone 6 and the precast slab splice connection zone 7 is a rubber ECC material with shrinkage compensation function. The rubber ECC material with shrinkage compensation function generates restricted micro-expansion during the hardening process and forms a dense connection with the side wall of the shear groove 5, the edge of the precast rubber ECC unit plate 1 and the bundled stud connector 4.

[0050] like Figure 4 As shown, structural steel bars 11 are provided in the grouting connection zone 6 of the shear groove. The structural steel bars 11 are connected to the pre-embedded steel bars in the precast rubber ECC unit plate 1 by lap splicing, binding or welding. Rubber ECC material with shrinkage compensation function is poured in the shear groove 5 to form a grouting connection zone that wraps the bundled stud connector 4.

[0051] like Figure 5 As shown, the precast slab splice connection area 7 includes a stepped splice formed by prefabrication at the edges of two adjacent precast rubber ECC unit slabs 1 and a reserved U-shaped steel bar 10. After inserting the steel bar, rubber ECC material with shrinkage compensation function is poured to realize the connection between adjacent precast rubber ECC unit slabs 1.

[0052] The construction method for the above-mentioned prefabricated orthotropic steel-rubber ECC composite bridge deck includes the following steps:

[0053] Step 1: Determine the local layout of the clustered stud connector 4. Before construction, the orthotropic steel bridge deck is first structurally identified and measured to determine the relative positions of the top plate 2, longitudinal ribs 8, transverse diaphragms 9, and their welds. After determining the longitudinal rib-top plate welds, transverse diaphragm-top plate welds, longitudinal rib-top plate-transverse diaphragm three-way intersecting welds, transverse diaphragm opening edges, and existing fatigue crack areas, the local layout of the clustered stud connector 4 on the top plate 2 is determined based on the interface shear force transfer requirements of the composite bridge deck, the location of wheel loads, the segment dimensions of the precast rubber ECC unit plates 1, and the structural layout of the orthotropic steel bridge deck. The clustered stud connector 4 is preferentially placed in non-fatigue-sensitive areas of the top plate 2, avoiding the longitudinal rib-top plate welds, transverse diaphragm-top plate welds, longitudinal rib-top plate-transverse diaphragm three-way intersecting welds, transverse diaphragm opening edges, and existing fatigue crack areas. After the position of the clustered stud connector 4 is determined, measurements are taken and lines are laid out on the top plate 2, and the center position, number of studs, stud spacing and stud arrangement direction of each group of clustered stud connectors 4 are marked.

[0054] Step 2: Prefabricate the precast rubber ECC unit panel 1 with shear grooves 5. Based on the local arrangement of the clustered stud connectors 4 determined in Step 1, shear grooves 5 are set at corresponding positions on the precast rubber ECC unit panel 1. The position, length, width, depth, and arrangement of the shear grooves 5 match the clustered stud connectors 4, ensuring that after the precast rubber ECC unit panel 1 is hoisted into place, the clustered stud connectors 4 can extend into the corresponding shear grooves 5. The precast rubber ECC unit panel 1 can be prefabricated in the factory using steel molds or combined templates. Before template installation, the template surface should be cleaned and a release agent applied. The forming mold for the shear grooves 5 should be set according to the design dimensions. After the rubber ECC material is poured into the mold, it can be formed by slight vibration, tamping, or scraping to avoid excessive vibration causing fiber segregation. After forming, the panel surface is smoothed, and a rough connection surface and stepped joint structure are formed on the sides of the precast rubber ECC unit panel 1. After prefabrication, curing is carried out until the prefabricated rubber ECC unit plate 1 reaches the lifting strength before demolding. The plate size, shear groove 5 forming condition, plate edge splicing structure and surface defects are then checked.

[0055] Step 3: Remove rust, grind, or sandblast the upper surface of the top plate 2. Before installing the precast rubber ECC unit plate 1, treat the upper surface of the top plate 2. First, remove oil, loose rust, old coatings, dust, and loose attachments from the surface of the top plate 2. When using sandblasting, quartz sand, steel grit, steel shot, or other suitable abrasives can be used. The sandblasting pressure can be 0.5 MPa-0.8 MPa, the distance between the nozzle and the steel plate surface can be 100 mm-300 mm, and the spray angle can be 45°-90°. After sandblasting, the surface of the top plate 2 should show a uniform metallic luster and be free of visible oil, scale, rust, and loose coatings. When using grinding, an angle grinder, grinding wheel, wire wheel, or belt sander can be used to grind along the longitudinal and transverse directions of the bridge to form a uniform rough interface on the surface of the top plate 2. For areas near welds, excessive grinding should be avoided to prevent damage to the original welds and the base material of the top plate 2. After treatment, compressed air, an industrial vacuum cleaner, or non-woven fabric should be used to remove surface dust and residual abrasive. The surface of top plate 2 should be kept dry, clean, and rough. If the surface becomes damp, contaminated, or rusted again before applying epoxy resin adhesive, it should be cleaned again.

[0056] Step 4: Weld the clustered stud connector 4 onto the top plate 2. Weld the clustered stud connector 4 onto the top plate 2 according to the arrangement determined in Step 1. Before welding, the layout position should be checked again to confirm that the center position of the stud matches the position of the shear groove 5 at the bottom of the precast rubber ECC unit plate 1. The welding area should be free of moisture, oil, rust, and dust. The clustered stud connector 4 can be made of cylindrical head studs, threaded studs, or circumferential rib studs. During welding, ensure that the studs are perpendicular to the surface of the top plate 2, and that a continuous, full weld leg is formed at the stud root after welding. After welding, check the stud position deviation, perpendicularity, and welding quality. The stud position deviation should be controlled within ±5 mm, and the perpendicularity deviation should be controlled within 5°. Studs with incomplete welds, off-center welds, burn-through, discontinuous weld legs, or obvious tilting should be removed and re-welded. If necessary, bending tests, hammer tests, or sampling pull-out tests can be used to inspect the stud welding quality.

[0057] Step 5: Remove welding slag and spatter from the welding process, and perform a secondary cleaning of the surface of the top plate 2. After the clustered stud connector 4 is welded, remove the welding slag, metal spatter, and localized oxides generated during the welding process. Cleaning can be done by tapping with a small hammer, brushing with a wire brush, lightly grinding with an angle grinder, blowing with compressed air, or vacuuming with an industrial vacuum cleaner. Welding spatter around the stud roots should be ground smooth to avoid affecting the continuous laying of the epoxy resin adhesive layer 3 and the placement of the precast rubber ECC unit plate 1. After the secondary cleaning, the upper surface of the top plate 2 should be free of obvious welding slag, dust, oil, and loose particles. If the surface of the steel plate is contaminated after the secondary cleaning, wipe it with acetone, anhydrous ethanol, or a special cleaning agent, and wait for the solvent to completely evaporate before proceeding to the next step of construction.

[0058] Step 6: Apply epoxy resin adhesive to the upper surface of the top plate 2 to form epoxy resin adhesive layer 3. After the surface of the top plate 2 is properly treated and kept dry and clean, apply the epoxy resin adhesive. A two-component epoxy resin adhesive can be used. Before construction, weigh component A and component B according to the product specifications and mix them evenly with a low-speed mixer for 2-5 minutes until the color and texture are uniform. Avoid introducing a large number of air bubbles during the mixing process. Application can be done with a scraper, notched scraper, roller, or trowel. The epoxy resin adhesive layer 3 should continuously cover the contact area between the precast rubber ECC unit plate 1 and the top plate 2, and the thickness can be controlled to 1 mm-10 mm. For the area around the studs, the corresponding area of ​​the shear groove 5, and the edge of the plate, ensure that the epoxy resin adhesive is spread continuously to avoid missed areas, dry spots, and obvious accumulation. After the epoxy resin adhesive is applied, the precast rubber ECC unit plate 1 should be hoisted and installed within its applicable open time.

[0059] Step 7: Hoist and position the precast rubber ECC unit panel 1. Use lifting tools, slings, and lifting rings to hoist the precast rubber ECC unit panel 1. Before hoisting, inspect the bottom shear groove 5, the edge joint structure, and the position of the lifting points of the precast rubber ECC unit panel 1 to confirm there are no obvious cracks, missing corners, chipped edges, or defects that may affect installation. During hoisting, lower the precast rubber ECC unit panel 1 slowly and position it using measurement control lines, positioning pins, guides, limit blocks, or temporary bolts. During the positioning process, gradually insert the clustered stud connectors 4 into the corresponding shear groove 5 to avoid collisions or jamming between the studs and the groove wall. After the precast rubber ECC unit panel 1 is in place, check the panel's planar position, elevation, joint width, and the alignment of the shear groove 5 with the clustered stud connectors 4.

[0060] Step 8: Pour shrinkage-compensating rubber ECC material into the precast slab joint connection area 7 between the shear groove 5 and the adjacent precast rubber ECC unit slab 1. After the precast rubber ECC unit slab 1 is positioned, pour shrinkage-compensating rubber ECC material into the precast slab joint connection area 7 between the shear groove 5 and the adjacent precast rubber ECC unit slab 1. Before pouring, check that the shear groove 5 and the precast slab joint connection area 7 are clean, dry, and free of debris. During the pouring process, manual tamping, light tapping of the template with a rubber hammer, and low-frequency micro-vibration can be used to assist compaction, but strong vibration should be avoided to prevent fiber segregation. After grouting, the surface of the shear groove 5 and the precast slab joint connection area 7 should be smoothed, and any excess material should be removed.

[0061] Step 9: Curing the shear groove grouting connection zone 6 and the precast slab joint connection zone 7. After pouring, the shear groove grouting connection zone 6 and the precast slab joint connection zone 7 should be cured. Before curing, avoid vehicle loads, construction disturbances, rainwater erosion, and sudden temperature changes. Curing can be carried out by covering with plastic film, wet burlap, sprinkling water for moisture retention, or covering with heat preservation materials. Under normal temperature conditions, the initial covering curing time should not be less than 24 hours, and the moisture retention curing time can be 3-7 days. When the ambient temperature is below 5 ℃, heat preservation measures should be taken. When the ambient temperature is above 30 ℃ or the wind speed is high, the covering and moisture retention should be strengthened to avoid rapid surface water loss. During the curing period, check whether there are obvious shrinkage cracks, hollow areas, segregation, or debonding phenomena in the slab joint connection zone 7 and the shear groove grouting connection zone 6. After the rubber ECC material with shrinkage compensation function, epoxy resin adhesive layer 3 and shear groove grouting connection area 6 reach the design strength, remove the temporary limiting device or counterweight device and clean the bridge deck surface.

[0062] Step 10: Install an asphalt wearing course on top of the precast rubber ECC unit slab 1 to ultimately form an assembled orthotropic steel-rubber ECC composite bridge deck structure. After the precast rubber ECC unit slab 1, the shear groove grouting connection area 6, and the precast slab joint connection area 7 have been properly cured, clean the upper surface of the precast rubber ECC unit slab 1 to remove laitance, dust, oil, and loose particles. If necessary, light shot blasting, grinding, or high-pressure air blowing can be used to create a clean, rough surface. Subsequently, a waterproof bonding layer and an asphalt wearing course are installed on top of the precast rubber ECC unit slab 1. After the waterproof bonding layer has cured or reached the paving conditions, the asphalt wearing course is laid. The asphalt wearing course can use modified asphalt mixture, epoxy asphalt mixture, cast-in-place asphalt mixture, or other wearing course materials suitable for steel bridge deck paving, with a thickness of 20 mm-50 mm. After the asphalt wearing course is laid, compaction, joint treatment, and surface inspection are performed. Once the temperature, compaction, flatness, anti-skid performance, and bonding quality of the wear layer meet the requirements, the prefabricated orthotropic steel-rubber ECC composite bridge deck structure is finally formed.

[0063] When damage occurs to a localized precast rubber ECC unit panel 1 during operation, the asphalt wear layer above it can be milled or removed first. Then, the precast panel joint connection area 7 around the unit panel to be replaced can be cut. Depending on the extent of the damage, the shear groove grouting connection area 6 can be locally broken, and the remaining material of the epoxy resin bonding layer 3 can be removed or ground. Subsequently, the damaged precast rubber ECC unit panel 1 can be removed. After inspecting and repairing the steel top plate 2 and the clustered stud connectors 4, epoxy resin bonding material can be reapplied, a new precast rubber ECC unit panel 1 can be installed, and rubber ECC material with shrinkage compensation function can be poured into the shear groove 5 and the precast panel joint connection area 7. After curing, the asphalt wear layer can be laid to restore the composite bridge deck structure.

[0064] For bridges with high traffic management requirements, a segmented construction method can be adopted. Precast rubber ECC unit panels 1 are prefabricated in the factory and transported to the site in advance. On-site work mainly involves positioning, grouting, and curing, thereby shortening the traffic closure time.

Claims

1. A prefabricated orthotropic steel-rubber ECC composite bridge deck, characterized in that: The system includes a prefabricated rubber ECC unit plate (1) and a top plate (2). An epoxy resin bonding layer (3) is provided between the prefabricated rubber ECC unit plate (1) and the top plate (2). Several shear grooves (5) are provided in the prefabricated rubber ECC unit plate (1) for inserting the clustered stud connectors (4). The shear grooves (5) are filled with rubber ECC material with shrinkage compensation function to wrap the clustered stud connectors (4) and form a shear groove grouting connection area (6). The clustered stud connectors (4) are welded to the top plate (2) at intervals and avoid fatigue sensitive areas. The prefabricated rubber ECC unit plates (1) are connected to each other through the prefabricated plate splice connection area (7).

2. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The clustered stud connector (4) includes multiple studs, which are arranged at intervals along the longitudinal and transverse directions. The spacing is determined according to the interface shear force transfer requirements between the precast rubber ECC unit plate (1) and the top plate (2).

3. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 2, characterized in that: The stud is an anchoring-enhanced stud, arranged in a rectangular or linear shape. The anchoring-enhanced stud includes an anchoring reinforcement part and a stud rod. The anchoring reinforcement part is one or more of a threaded section, a circumferential rib, and a dotted protrusion. The anchoring reinforcement part forms a mechanical engagement with the rubber ECC material with shrinkage compensation function in the shear groove grouting connection area (6).

4. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The shrinkage-compensating rubber ECC material comprises cement-based cementitious material, fine aggregate, waste tire rubber granules, chopped fibers, expansion component, shrinkage-reducing component, water-reducing agent, and water. Based on the total mass of the solid components of the shrinkage-compensating rubber ECC material, the cement-based cementitious material comprises 45%-75%, the fine aggregate comprises 10%-35%, the rubber granules comprises 5%-15%, the chopped fibers comprises 0.5%-3%, the expansion component comprises 2%-10%, the shrinkage-reducing component comprises 0.1%-2%, and the water-reducing agent comprises 0.1%-2%.

5. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The shear groove (5) is stepped. The reserved position of the shear groove (5) on the prefabricated rubber ECC unit plate (1) is determined according to the position of the clustered stud connector (4), and forms a mechanical engagement with the rubber ECC material with shrinkage compensation function filled therein.

6. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The shear groove grouting connection area (6) is provided with structural steel bars (11), which are connected to the pre-embedded steel bars in the prefabricated rubber ECC unit plate (1) by lap splicing, binding or welding.

7. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The precast slab splice connection area (7) includes stepped splices and U-shaped steel bars (10). After inserting the steel bars, rubber ECC material with shrinkage compensation function is poured to realize the connection between adjacent precast rubber ECC unit slabs (1).

8. The assembled orthotropic steel-rubber ECC composite bridge deck according to claim 1, characterized in that: The top plate (2) is provided with longitudinal ribs (8) on the side away from the prefabricated rubber ECC unit plate (1), and the longitudinal ribs (8) are welded and fixed to the top plate (2) and the transverse partition (9).

9. A prefabricated orthotropic steel-rubber ECC composite bridge deck according to claim 8, characterized in that: The longitudinal rib (8) is one or more of the following: U-rib, plate rib, closed rib or open rib.

10. A construction method for a prefabricated orthotropic steel-rubber ECC composite bridge deck according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Identify the welds or existing fatigue crack areas of the orthotropic steel bridge deck, and determine the arrangement position of the clustered stud connectors (4) on the top plate (2) according to the interface shear force transfer requirements of the composite bridge deck. Step 2: Set shear grooves (5) at the corresponding positions of the prefabricated rubber ECC unit plate (1) and prefabricate the prefabricated rubber ECC unit plate (1). Step 3: Remove rust, grind or sandblast the upper surface of the top plate (2); Step 4: Weld the clustered stud connector (4) to the top plate (2) at the position determined in Step 1. Step 5: Remove the welding slag and spatter generated during welding, and perform a secondary cleaning of the surface of the top plate (2); Step 6: Apply epoxy resin adhesive to the upper surface of the top plate (2) to form an epoxy resin adhesive layer (3). Step 7: Hoist and position the prefabricated rubber ECC unit plate (1) so that the clustered stud connector (4) extends into the corresponding shear groove (5); Step 8: Pour rubber ECC material with shrinkage compensation function into the precast plate splice connection area (7) between the shear groove (5) and the adjacent precast rubber ECC unit plate (1) after the reinforcement is inserted. Step nine involves curing the shear groove grouting connection area (6) and the precast slab splice connection area (7) to form an assembled orthotropic steel-rubber ECC composite bridge deck.

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