Self-leveling prefabricated assembled pavement slabs for airport pavement slab replacement

Abstract

The present invention provides a self-leveling prefabricated assembled pavement slab for airport pavement slab replacement, which includes a precast slab with a profiled steel frame. Reserved grooves are arranged at the bottom corners of the precast slab, and leveling bolts are arranged in the reserved grooves; the profiled steel frame includes an upper angle steel and a lower angle steel. The upper angle steel is closely attached to the inner wall and the top wall of the reserved groove, and the lower angle steel is fixed on the ground; the leveling bolt includes an upper screw rod, a lower screw rod and an adjusting nut. The upper screw rod is fixed to the upper angle steel, the lower screw rod is fixed to the lower angle steel, and the upper screw rod and the lower screw rod are connected by the adjusting nut. The adjusting nut is rotated to adjust the distance between the upper screw rod and the lower screw rod. The leveling bolt of the present invention transfers force to the base layer through the profiled steel, and realizes two-way adjustment through the intermediate nut, reduces the local stress at the bolt and has a fast leveling speed. The side grooves are coordinated with the slab joints, and the process is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of airport pavements, and specifically to a self-leveling prefabricated assembled pavement slab for airport pavement slab replacement. Background Art

[0002] Quick repair of local diseases of airport cement concrete pavements has always been an urgent problem to be solved. Prefabricated assembled pavement slabs have become an optional solution for quick repair of airport pavements due to their low cost and good durability during their entire life cycle. From the perspective of the existing prefabricated airport pavements used for repair applications, there are mainly four technical problems during their installation and use, namely: load transfer between slabs, subgrade treatment, slab surface leveling, and joint durability. Regarding slab surface leveling, the main measures at home and abroad are bolt leveling currently.

[0003] Chinese Patent with the publication number CN 113047111 A proposes an angle steel assembled pavement slab structure for airport runways, and fixes the leveling bolt and nut assembly to adjacent angle steels through a connecting piece. Chinese Patent with the publication number CN 114293427 A uses bolt leveling, and the bolts are arranged in the mortise grooves at the four corner points, and the mortise grooves are welded together with the threaded steel bars. Chinese Patent with the publication number CN216786734 U integrates the functions of the leveling bolt with the lifting ring and the grouting hole, and the leveling bolt is arranged at a certain distance from the corner point. Patent CN 214882670 U levels through square steel pipes and fine sand, and its main function is leveling.

[0004] During the process of leveling the slab using bolts, the material contacted by the bottom of the bolt may powder due to excessive pressure, resulting in the bolt sinking into the subgrade and being unable to adjust the slab height. In addition, the bolt holes need to be sealed, increasing the working procedures. Summary of the Invention

[0005] In order to solve the problems of the existing technology, the present invention provides a self-leveling prefabricated assembled pavement slab for airport pavement slab replacement. The leveling bolt transfers force to the subgrade through the profiled steel, and realizes two-way adjustment through the intermediate nut, reducing the local stress at the bolt and having a fast leveling speed. The side groove is coordinated with the slab joint for treatment, simplifying the working procedures.

[0006] The present invention includes a precast slab with a profiled steel frame. Reserved grooves are arranged at the bottom corners of the precast slab, and leveling bolts are arranged in the reserved grooves; the profiled steel frame includes an upper angle steel and a lower angle steel. The upper angle steel is closely attached to the inner wall and the top wall of the reserved groove, and the lower angle steel is fixed on the ground; the leveling bolt includes an upper screw rod, a lower screw rod and an adjusting nut. The upper screw rod is fixed to the upper angle steel, the lower screw rod is fixed to the lower angle steel, and the upper screw rod and the lower screw rod are connected through the adjusting nut. Rotate the adjusting nut to adjust the distance between the upper screw rod and the lower screw rod.

[0007] For further improvement, the upper screw rod is fixed to the upper angle steel by welding with a fixing nut, and the lower screw rod is fixed to the lower angle steel by welding with a fixing nut.

[0008] For further improvement, the height of the adjusting nut is 6 cm to 10 cm, and the adjustable height difference is 2 cm to 5 cm.

[0009] For further improvement, when the middle nut is screwed to one side, the upper screw rod and the lower screw rod approach each other, and the surface of the precast slab is lowered; when the middle nut is screwed to the other side, the upper screw rod and the lower screw rod move away from each other, and the surface of the precast slab is lifted.

[0010] During the prefabrication of the slab, the angle steel can act as part of the formwork. The upper and lower sections of the leveling bolt are placed together, so that the slab is in the lowest elevation state. After the slab is installed in place, according to the relative elevation between the replaced slab and the surrounding slabs, the leveling bolts at the corresponding positions are adjusted to make the elevations of the two side slabs coordinated. After the installation is completed, the grooves and the joints between the slabs are grouted and sealed together.

[0011] The beneficial effects of the present invention are as follows:

[0012] 1. The perimeter of the precast slab is provided with a profiled steel frame, which increases the stiffness of the slab and has a positive effect on preventing cracking at the edges and corners of the slab;

[0013] 2. The leveling bolts are welded to the profiled steel, which can avoid the problem that the end part directly contacts the base layer, causing excessive local stress at the end and piercing into the base layer;

[0014] 3. The two-way adjustment through the middle nut can speed up the leveling speed;

[0015] 4. The closed process of the conventional leveling bolt holes is removed, which further simplifies the installation. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a plan view of the slab;

[0018] Figure 2 It is Figure 1 Sectional view I-I in

[0019] Figure 3 It is a schematic diagram before the adjustment of the leveling bolt;

[0020] Figure 4 It is a schematic diagram after the adjustment of the leveling bolt;

[0021] In the figure, 1 is a steel section frame, 2 is a precast slab, 3 is an upper angle steel, 4 is a leveling bolt, 5 is a lower angle steel, 6 is an adjusting nut, 7 is an upper screw rod, 8 is a lower screw rod, and 9 is a fixing nut. Embodiment

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0023] The structure of the present invention is as Figure 1 and Figure 2 shown, and it includes a precast slab 2 using a steel section frame 1. A reserved groove is provided at the bottom corner of the precast slab, and a leveling bolt 4 is arranged in the reserved groove; the steel section frame includes an upper angle steel 3 and a lower angle steel 5. The upper angle steel is closely attached to the inner wall and the top wall of the reserved groove, and the lower angle steel is fixed on the ground; the leveling bolt includes an upper screw rod 7, a lower screw rod 8, and an adjusting nut 6. Among them, the upper screw rod is fixed to the upper angle steel, the lower screw rod is fixed to the lower angle steel, and the upper screw rod and the lower screw rod are connected by the adjusting nut. Rotate the adjusting nut to adjust the distance between the upper screw rod and the lower screw rod.

[0024] The structure of the leveling bolt 4 is as Figure 3 and Figure 4 shown. The upper screw rod is welded and fixed to the upper angle steel through a fixing nut 9, and the lower screw rod fixing nut is welded and fixed to the lower angle steel. When the intermediate nut is screwed to one side, the upper screw rod and the lower screw rod approach each other, and the surface of the precast slab is lowered; when the intermediate nut is screwed to the other side, the upper screw rod and the lower screw rod move away from each other, and the surface of the precast slab is lifted.

[0025] During the prefabrication of the slab, the angle steel can play the role of part of the formwork. The upper and lower sections of the screw rod of the leveling bolt are close together, as Figure 3 shown, even when the slab is in the lowest elevation state; after the slab is installed in place, according to the relative elevation of the replaced slab and the surrounding slabs, adjust the leveling bolts at the corresponding positions to make the elevations of the two side slabs coordinated, as Figure 4 shown. After installation, the joints between the groove and the slab are grouted and sealed together.

[0026] A specific embodiment of the present invention is as follows:

[0027] For square slabs such as 4m×4m, 5m×5m or 6m×6m of general airport pavements, considering the convenience of precast slab transportation and the lifting weight, when the slab is repaired and replaced, it can be precast in two rectangular slabs. If the transportation and lifting conditions permit, it can also be precast as a whole. When precasting, first make a steel section frame, and the height of the frame is made half of the slab thickness. Then pour concrete with the steel section frame and additional formwork, which can ensure that the top surface of the pavement is all concrete. The concrete grade should be C30 or above.

[0028] The present invention can be applicable to situations such as airport slab sizes of 4m×4m, 5m×5m, 2m×4m, 2.5m×5m, 6m×6m or 3m×6m, etc. The slab thickness is 30cm - 45cm, the slope is generally set below 1%, and the height difference between the installed slab and the surrounding slabs is within 5cm. The designed height of the middle nut can be 6cm - 10cm, and the adjustable height difference is 2cm - 5cm. The heights of the upper and lower screw rods are determined according to the slab thickness. The upper and lower screw rods are welded to the upper and lower angle steels respectively through the fixing nuts at both ends.

[0029] The leveling bolts of the present invention are arranged in the steel section frame. For side lengths of 4m and above, 3 groups of leveling bolts can be set; when it is less than 3m, 2 groups of leveling bolts can be set, and the specific quantity is finely adjusted according to the slab thickness and plane size. When making the steel section frame, the upper and lower screw rods of the leveling bolts are closely placed together, and the upper and lower angle steels are connected together through the leveling bolts to form the steel section frame. The side of the upper angle steel serves as the side formwork of the concrete slab and plays a constraining role. The side of the lower angle steel overlaps the side of the upper angle steel by 5 - 10cm, which can change with the adjustment of the leveling bolts.

[0030] During the processes of slab precasting, curing, transportation and lifting, the leveling bolts are in the state where the upper and lower screw rods are closely placed together. After the slab is installed in place, according to the height difference between the slab and the surrounding slabs, the height difference is adjusted by adjusting the middle nut. During specific operation, a crank wrench can be inserted into the reserved groove to rotate the middle nut.

[0031] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments. In particular, for the equipment embodiments, the above description is only the preferred implementation manner of the present invention. Since it is basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments. The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. For any person skilled in the art in the technical field disclosed by the present invention, for those of ordinary skill in the technical field, the changes or substitutions that can be easily thought of without departing from the principle of the present invention should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A self-leveling prefabricated assembled pavement slab for airport pavement slab replacement, characterized in that: It includes precast slabs with profiled steel frames. Reserved grooves are provided at the bottom corners of the precast slabs, and leveling bolts are arranged in the reserved grooves. The profiled steel frame includes upper angle steel and lower angle steel. The upper angle steel is closely attached to the inner wall and the top wall of the reserved groove, and the lower angle steel is fixed on the ground. The leveling bolt includes an upper screw rod, a lower screw rod and an adjusting nut. The upper screw rod is fixed to the upper angle steel, and the lower screw rod is fixed to the lower angle steel. The upper screw rod and the lower screw rod are connected by the adjusting nut. The adjusting nut is rotated to adjust the distance between the upper screw rod and the lower screw rod. The upper screw rod is welded and fixed to the upper angle steel through a fixing nut, and the lower screw rod is welded and fixed to the lower angle steel through a fixing nut. The leveling bolts connect the upper angle steel and the lower angle steel together to form a profiled steel frame. The height of the adjusting nut is 6 cm to 10 cm, the adjusting height difference is 2 cm to 5 cm, and the side of the lower angle steel overlaps with the side of the upper angle steel by 5 to 10 cm.

2. The self-leveling prefabricated assembled pavement slab for airport pavement slab replacement according to claim 1, characterized in that: When the middle nut is screwed to one side, the upper screw rod and the lower screw rod approach each other, and the surface of the precast slab drops; when the middle nut is screwed to the other side, the upper screw rod and the lower screw rod move away from each other, and the surface of the precast slab rises.

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