Reinforced pavement slab

Abstract

The utility model relates to road construction, specifically to precast road pavement structures made of reinforced concrete slabs intended for the construction of highways, temporary access roads, and other transport routes. The invention aims to increase strength, which is achieved by the claimed device comprising slabs 6, each of which is provided with channel formers 1 for a post-tensioned cable 7, an embedded pipe 2 for a connecting rod 4, an embedded part 3 for slinging, composite reinforcement 5 in backfill, an expansion joint 8, and 5.

Description

[0001] The utility model relates to the field of road construction, namely to the structures of prefabricated road surfaces made of reinforced concrete slabs, intended for the construction of highways, temporary access roads and other transport routes.

[0002] A wide range of transport structures where traditional concrete or asphalt concrete pavements exhibit insufficient strength and durability due to high loads and exposure to corrosive factors. Deformations occur due to repeated dynamic wheel loads, loss of pavement strength caused by the continuous impact of vehicle wheels, and natural and climatic factors.

[0003] Precast concrete pavements allow for faster construction, but their known designs have operational drawbacks: displacement of adjacent slabs under load, loss of rigidity of the slab package over time due to weakening of stresses in the butt joints.

[0004] Various designs of prefabricated and disassemblable road surfaces are known from the prior art.

[0005] An analogue of a motorway is known in the description of a utility model to patent RU 84857 U1; IPC E01C 3 / 00 for application No. 2009103254, dated 03.02.2009, published 20.07.2009, bulletin. No. 20, comprising a base, a sub-base with a permeability coefficient of at least 3 m / day and a concrete pavement, wherein the road base is made of soil up to 50 cm high above the ground surface, the sub-base is made of sand with a layer thickness of 10÷30 cm, and the concrete pavement is made of prefabricated monolithic stressed reinforced concrete slabs, 10÷15 cm thick, with grooves at the ends, connected by steel cables with an anti-corrosion coating and filled in at the points of contact of the ends of the bitumen mast slabs with a layer at least 4 mm thick, and covered on the upper side with asphalt or bitumen pavement with granite chips, with a waterproof film laid between the sub-base and the concrete pavement.

[0006] Disadvantages: Insufficient strength. The longitudinal bond of the slabs is achieved primarily by friction and filling the end joints with bitumen mastic. The tongue-and-groove joints of the ends do not provide sufficient compression of the package. As a result, under repeated dynamic loads from the wheels of heavy vehicles and temperature changes, joint deformations occur, seams open, and the slabs shift relative to each other.

[0007] An analogue of the combined temporary road structure is known in the description of the utility model to the patent CN 111663397 A; IPC E01C11 / 00; E01C5 / 00; E01C9 / 08 according to application No. 202010707139 dated 07 / 21 / 2020, published. 15.09.2020, connected by a steel cable, which comprises a road surface panel, a connecting block, a steel cable and a steel cable lock, and the connecting block is provided with two arcuate connecting surfaces, several road panels are arranged in the form of an array, the connecting block is installed between two adjacent road panels, and the arcuate connecting surface of the connecting block is connected to the end surfaces of the road plate, several steel cables are attached to the end surfaces of the road plate and to each other, passing through the road plate and the connecting block, and the steel cable locks are fixed at both ends of each steel cable.

[0008] Disadvantages: Insufficient strength. The steel cables in the structure are passed through the panels and secured with locks, which prevents them from being tensioned. This prevents longitudinal compression of the slab stack, resulting in displacement of the elements under load, opening of the joints, and consequently, damage to the road surface.

[0009] A prototype temporary artificial road is known for patent CN 215857014 U; E01C11 / 02; E01C9 / 08 according to application No. 202121665482, dated 07 / 21 / 2021, published 02 / 18 / 2022, consisting of a plurality of panels, characterized in that: a hole for a cable is provided at both ends of an individual panel, and a connecting cable will pass through the hole for the cable, which connects the plurality of panels into a single whole; a single panel is provided with connecting steel rods on one side and a positioning gap on the other side. The positioning gap and connecting steel rods ensure the connection of two adjacent panels.

[0010] Disadvantages: Insufficient strength. In the prototype, the connecting cables are simply passed through the panels, without the use of channel formers, and are secured with limiters, creating no longitudinal compression of the stack. Because of this, the panel joints are susceptible to opening under dynamic loads, and the stack functions as a disconnected sequence of elements, significantly reducing the overall longitudinal rigidity of the pavement. This version is also designed for temporary road construction only.

[0011] The technical result is increased strength.

[0012] Also, the claimed technical solution is aimed at increasing the rigidity of the plate package.

[0013] The technical result is achieved due to the fact that the slab for reinforced road surfaces contains embedded pipes and connecting rods at the joined ends, and also has embedded parts for slinging, a channel former made in the form of a hollow pipe and designed with the possibility of passing a cable with post-tensioning, while the slab is reinforced with composite reinforcement with backfill.

[0014] The presence of channel formers in the slabs and post-tensioned steel cables running through them creates a longitudinal compressive force in the assembled package, which ensures the package's integrity and prevents joint opening under load. However, cable compression alone would be insufficient without securing the slabs against mutual displacement in the transverse and vertical directions. This function is performed by embedded pipes at the abutting ends and connecting rods inserted into them, which form a rigid interlocking connection and ensure the joint operation of adjacent slabs as a single beam system. The integrity and load-bearing capacity of the slab itself under significant compressive stresses and operational loads is guaranteed by the use of composite reinforcement with backfill. With its high tensile strength, this effectively absorbs tensile forces and prevents corrosion-induced weakening of the cross-section.

[0015] The presence of essential features that distinguish it from the prototype allows the claimed technical solution to be recognized as new.

[0016] The possibility of implementing the claimed device in industry allows it to be recognized as meeting the criterion of industrial applicability.

[0017] The essence of the device is explained by the drawing, where:

[0018] Fig. 1 shows the layout of the embedded parts

[0019] Fig. 2 shows the layout of the embedded parts.

[0020] Fig. 3 shows the reinforcement diagram of the slab

[0021] Fig. 4 shows the diagram of laying and joining the slabs.

[0022] Fig. 5 shows a diagram of the laying and joining of slabs.

[0023] The device consists of a plate 6, which is made with channel formers 1 for a rope 7 with post-tensioning, an embedded pipe 2 for a connecting rod 4, an embedded part 3 for slinging, composite reinforcement 5 in backfill, an expansion joint 8.

[0024] The claimed plate is installed as follows.

[0025] Reinforced concrete slabs (6) are laid on a pre-prepared and chemically strengthened soil base. Slabs (6) can be made of heavy-duty concrete, geopolymer concrete, fiber-reinforced concrete, or high-strength concrete. The advantage of using concrete slabs (6) is their high durability and reserve load-bearing capacity to maintain long-term performance characteristics. Slabs (6) are reinforced with backfilled composite reinforcement (5), which absorbs tensile stresses and ensures the required load-bearing capacity. Backfilled composite reinforcement (5) is steel reinforcement or non-metallic composite rods made of glass, basalt, or carbon fibers. A layer of abrasive material (quartz sand or corundum) is applied to the surface of the rod during the manufacturing process before the binder polymerizes, greatly increasing adhesion to the concrete.This type of rebar offers a stronger and more durable alternative to metal in structures subject to significant loads, particularly where corrosion resistance is required. Rods 2 are made of durable fibers (glass, basalt, or carbon) and a polymer binder. Unlike rebar with a periodic profile (spiral wound), adhesion to the concrete is ensured by the sand backfill. This type of rebar has high tensile strength.

[0026] The upper (front) side of slab 6 is notched to ensure traction with vehicle wheels. Adjacent slabs 6 are connected in the pavement using two types of connections. Structurally, slabs 6 are joined using a "lock" connection, which consists of a connection between connecting rod 4 and a grooved insert pipe 2 for connecting rod 4, preventing vertical displacement. To absorb shear forces and transfer loads transversely between slabs 6, they are provided with channel formers 1 for post-tensioned steel cable 7. During installation, connecting reinforcement rods 2 are inserted into connecting rod 2 of adjacent slabs 6, rigidly fixing the elements relative to one another. To create prestressing and impart integrity and high longitudinal rigidity to the pavement, slabs 6 are assembled into bundles using steel cables 7.Cables 7 are passed through ducts 1, pre-embedded in slabs 6 during their manufacture. Ducts 1 are intended for embedding in concrete to create space for pulling prestressed cables. They are permanent hollow pipes or sleeves with an oil lubricant inside, which are embedded in the body of the concrete structure before it is poured. Ducts 1 are secured to the reinforcement cage using plastic clamps or binding wire. Fixings ("stools" or "stars") can also be used to provide the designed protective layer. This prevents displacement during concrete vibration. Due to post-tensioning without adhesion of the reinforcement to the concrete, ducts 1 prevent cable displacement during concreting. Ducts 1 perform a protective function, allowing cable pulling after the structure has been concreted.Post-stressing improves the deformation characteristics of the road surface under dynamic impacts.

[0027] Anchor blocks (slabs with conical holes and collet clamps) are installed at the ends of concrete slabs 6. They are secured to the end formwork and connected to the channel former with transition couplings to ensure a tight seal during concreting. The anchor block consists of anchor plates for transmitting tension loads to concrete slab 6, and the cables in the anchor device are clamped using collets. One end of the anchor plates has a spiral winding, which is embedded in the structure of slab 6 to support the loads during tensioning of cables 7. The anchor device is equipped with a niche former and a protective anti-corrosion capsule.

[0028] After assembling the package, the ropes 7 are tensioned and secured in the anchor device. To prevent corrosion, the ropes 7 are individually coated with a lubricated plastic sheath. Post-tensioning occurs as follows: the plates 6 are placed in a package on the foundation, and the anchor devices are installed. Using a rope pusher, the ropes 7 are threaded into the channel formers 1, then hydraulic jacks with pressure gauges are installed and connected to the pumping station. The rope is tensioned alternately on each side of the cross-section of the plate 6, symmetrically. After tensioning, the rope 7 is secured in the anchor device using a collet clamp. The initial tension in the rope 7 is 1000-1400 MPa, and the compression force of the package is 15-30 kgf / cm². The exact value of the compression force and the diameter and number of ropes 7 are calculated depending on the operating load and the climatic conditions of operation.

[0029] Creating an initial stress of 1000-1400 MPa in the ropes ensures a residual compression of 15-30 kgf / cm² after losses (shrinkage, creep, friction). This compensates for tensile stresses in the lower zone of the slabs during bending under wheel loads; prevents joints between slabs from opening even under repeated dynamic impacts; and maintains the design position of the connecting rods and locks, preventing their deformation. This achieves the stated technical result – increased strength.

[0030] The formed packs of plates 6 are separated from each other by an expansion joint 8. To carry out the gripping and movement of the plates 6 by crane equipment, each plate contains embedded parts for slinging 3.

[0031] The claimed utility model has a number of advantages over known devices:

[0032] - Unlike traditional steel reinforcement, it offers absolute resistance to chemical and electrochemical corrosion, as well as physical degradation. This completely eliminates the risk of coating failure due to corrosive expansion of the reinforcing bars. This ensures the slab maintains its load-bearing capacity over time, including during prolonged use in aggressive environments (moisture, de-icing salts, freeze-thaw cycles, and wet-dry conditions), and allows for a 30-50 year service life without major repairs.

[0033] - Composite reinforcement is 3-4 times lighter than steel, significantly reducing the weight of each slab 6 even at the factory production stage. Combined with the integrated slab mounting hardware (item 3), this simplifies loading, unloading, and installation, allows for the use of lighter-duty equipment, and accelerates pavement installation.

[0034] - The combination of longitudinal compression of the package with post-tensioned steel cables and connecting rods in coaxial embedded pipes eliminates vertical and horizontal mutual displacement of adjacent slabs under load. This ensures consistent evenness of the road surface throughout its service life and also reduces impact dynamic loads on the pavement itself.

[0035] - All connections between 6 slabs are detachable: the post-tensioning cables can be removed, the cables can be withdrawn, and the connecting rods can be dismantled. Slabs removed from the road surface retain their original geometry and strength characteristics. They can be re-laid on the same site after repair or moved for construction on another road section. This significantly reduces repair costs and ensures high installation speeds throughout all construction seasons.

[0036] The use of the claimed utility model will increase the strength.

Claims

A slab for reinforced road surfaces, containing embedded pipes and connecting rods at the abutting ends, characterized in that it has embedded parts for slinging, a channel former made in the form of a hollow pipe with the possibility of passing a cable with post-tensioning, while the slab is reinforced with composite reinforcement with backfill.

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