A method for continuously tensioning pavement oblique prestressed tendons

Abstract

The present application relates to a kind of pavement oblique prestressed tendon continuous tension construction method, belong to road engineering technical field, using the following steps: 1: multiple two-way anchoring device is connected head-to-tail to form the device combination of required length, and equidistantly arranged;2: in the through hole of previous device combination, first group of prestressed tendon is passed and anchored, then obliquely passes through the through hole of opposite direction on the subsequent device combination;And in the through hole of subsequent device combination, second group of prestressed tendon is passed and anchored;3: between previous device combination and subsequent device combination, reinforcing mesh is laid and concrete is poured, and form a pavement slab;4: when pavement slab is cured to 75% of design strength, first group of prestressed tendon is tensioned;5: repeat 3-4, continuously complete multiple pavement slab until the whole pavement is completed.The present application forms the circulation construction process of continuous tension by two-way anchoring device, realizes the transmission of two-way prestress, eliminates post-cast strip, saves construction period.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of road engineering, and particularly relates to a continuous tensioning construction method for oblique prestressed tendons of a pavement. BACKGROUND

[0002] In road engineering, pavements bear loads from above. In order to prevent the loads from causing the pavement concrete to crack and improve the durability and service life of the pavement, prestressed concrete technology is applied to pavement engineering of various roads, especially pavement structures of airport runways and taxiways, which often bear huge impact loads from airplane takeoff and landing, repeated bending and tensile loads, and temperature stresses caused by environmental temperature changes. Different loads in different directions need to be dealt with, and the oblique arrangement of prestressed tendons can better offset loads from different directions, and has superior stress performance, so it has been more and more widely applied in recent years.

[0003] However, the current construction process of "one-way anchoring + post-pouring strip" for pavements with oblique prestress has the following problems: in the warehouse splicing construction, the pavement slabs of adjacent warehouses are independent of each other, and their anchoring areas cannot be completely spliced in structure, so it is necessary to use post-pouring strip backfill to eliminate the splicing gap, which causes the construction period to be significantly prolonged, the structural integrity and durability to be damaged, the construction quality to be difficult to control, and the cost to be increased due to complex processes. SUMMARY

[0004] The present application aims to solve the problems in the prior art, and provides a continuous tensioning construction method for oblique prestressed tendons of a pavement, which completely cancels the post-pouring strip and realizes the assembly installation and integrated construction of the pavement slab.

[0005] The technical scheme is as follows:

[0006] A continuous tensioning construction method for oblique prestressed tendons of a pavement, which adopts the following steps:

[0007] Step 1: A plurality of bidirectional anchoring devices are connected head to tail to form a device combination with a desired length, and are arranged at equal intervals, wherein the bidirectional anchoring device is a cuboid with two notches on each long side, one long side of the cuboid is an anchoring end, the other long side is a tensioning end, the notches are inverted isosceles trapezoids, at least two oblique through holes are formed on the waist of each isosceles trapezoid, the through holes on the waist of the upper or lower isosceles trapezoid near the center of the cuboid are communicated with the through holes of the obliquely opposite isosceles trapezoid, the through holes on the waist of the upper or lower isosceles trapezoid near the two ends of the cuboid are communicated at the end of the cuboid, one short side of the cuboid has a groove, the other short side has a protrusion corresponding in size to the groove, and the protrusion of the latter cuboid is embedded into the groove of the former cuboid in sequence, and the through holes on the waist of the isosceles trapezoid of one end of the former cuboid are communicated with the through holes of the obliquely opposite isosceles trapezoid of the connected end of the latter cuboid.

[0008] Step 2: Insert the first set of prestressing tendons into the through hole of the previous device assembly and anchor one end of the first set of prestressing tendons to the anchorage end of the previous device assembly using an anchor. Then, insert the first set of prestressing tendons obliquely through the through hole of the next device assembly in the opposite direction. Insert the second set of prestressing tendons into the through hole of the next device assembly and anchor one end of the second set of prestressing tendons to the anchorage end of the next device assembly using an anchor.

[0009] Step 3: Lay a steel mesh and pour concrete between the previous and next assembly to form a pavement panel;

[0010] Step 4: When the pavement slab has been cured to 75% of its design strength, tension the first set of prestressing tendons. After tensioning, anchor the other end of the first set of prestressing tendons to the tensioning end of the next device assembly using anchors. Then, pass the second set of prestressing tendons obliquely through the through hole in the opposite direction on the third device assembly.

[0011] Step 5: Repeat steps 3-4 to continuously pour and tension the prestressing tendons of multiple pavement panels until the entire pavement is completed.

[0012] Furthermore, the groove and corresponding protrusion of the bidirectional anchoring device are both isosceles trapezoids with a base angle of 60°, and the base angle of the isosceles trapezoid of the notch is 25°-45°.

[0013] Furthermore, in the assembly of bidirectional anchoring devices, the oblique prestressing tendons at the edge of the pavement panel pass through the through holes in the grooves and protrusions of the anchoring device at the edge and are then fixed to the grooves and protrusions by anchors.

[0014] Furthermore, the upper part of the bidirectional anchoring device is the anchoring end, and the lower part is the tensioning end. The device combination formed by connecting multiple bidirectional anchoring devices is the width of the pavement panel, which ranges from 7 to 10 meters. The distance between the tensioning end of one device combination and the anchoring end of another device combination is the length of the pavement panel, which ranges from 10 to 20 meters.

[0015] Furthermore, the curing time for a single pavement panel is 7-14 days.

[0016] Furthermore, the continuous tensioning method for inclined prestressed tendons in pavement construction is applied to the pavement construction of airport runways or taxiways.

[0017] Beneficial effects:

[0018] 1) This invention uses a bidirectional anchoring device to simultaneously serve as the "tensioning end of the front slab" and the "anchoring end of the rear slab" in two adjacent pavement panels, forming a continuous tensioning cycle construction process of "pouring the front slab - tensioning the front slab - anchoring connection - pouring the rear slab - tensioning the rear slab - anchoring connection". This achieves bidirectional prestress transfer, eliminates the post-pouring strip, improves the overall integrity of the pavement, and significantly reduces the pavement construction cycle. Attached Figure Description

[0019] Fig. 1 This is a schematic diagram of multi-plate splicing in the continuous tensioning construction method of inclined prestressed tendons for pavement according to the present invention;

[0020] Fig. 2 This is a schematic diagram of the bidirectional anchoring device.

[0021] Fig. 3 A schematic diagram of a device assembly formed by connecting two bidirectional anchoring devices;

[0022] Wherein: 1 is a notch, 2 is a through hole, 3 is a groove, and 4 is a protrusion. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit it. Terms such as "upper," "lower," "front," "rear," "left," "right," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the purpose of describing the invention. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0024] like Figs. 1-3 The method for continuous tensioning of inclined prestressing tendons in pavement construction, as shown, comprises the following steps:

[0025] Step 1: Connect multiple bidirectional anchoring devices end to end to form a device assembly of the required length and arrange them at equal intervals. The bidirectional anchoring device is a cuboid with two notches 1 on each side of its long side. One long side of the cuboid is the anchoring end, and the other long side is the tensioning end. The notch 1 is an inverted isosceles trapezoid. Each isosceles trapezoid has at least two oblique through holes 2 on its waist. The through hole 2 on the waist of the upper or lower isosceles trapezoid near the center of the cuboid is connected to the through hole 2 of the isosceles trapezoid in the opposite direction. The through holes 2 on the waist of the upper or lower isosceles trapezoid near both ends of the cuboid are connected to the ends of the cuboid. One short side of the cuboid has a groove 3, and the other short side has a protrusion 4 corresponding to the size of the groove. The cuboids are connected sequentially by embedding the protrusion 4 of the next cuboid into the groove 3 of the previous cuboid. The through hole 2 on the waist of the isosceles trapezoid at one end of the previous cuboid is connected to the through hole 2 of the isosceles trapezoid in the opposite direction at the connected end of the next cuboid.

[0026] Step 2: Insert the first set of prestressing tendons into the through hole of the previous device assembly and anchor one end of the first set of prestressing tendons to the anchorage end of the previous device assembly using an anchor. Then, insert the first set of prestressing tendons obliquely through the through hole of the next device assembly in the opposite direction. Insert the second set of prestressing tendons into the through hole of the next device assembly and anchor one end of the second set of prestressing tendons to the anchorage end of the next device assembly using an anchor.

[0027] Step 3: Lay a steel mesh and pour concrete between the previous and next assembly to form a pavement panel;

[0028] Step 4: When the pavement slab has been cured to 75% of its design strength, tension the first set of prestressing tendons. After tensioning, anchor the other end of the first set of prestressing tendons to the tensioning end of the next device assembly using anchors. Then, pass the second set of prestressing tendons obliquely through the through hole in the opposite direction on the third device assembly.

[0029] Step 5: Repeat steps 3-4 to continuously pour and tension the prestressing tendons of multiple pavement panels until the entire pavement is completed.

[0030] The grooves and corresponding protrusions of the bidirectional anchoring device are both isosceles trapezoids with a base angle of 60°, while the base angles of the notched isosceles trapezoids range from 25° to 45°. Each side of the notched isosceles trapezoid has an even number of through holes, divided into two groups: one group for passing through the prestressing tendons anchored at the anchoring end, and the other group for passing through the prestressing tendons anchored at the tensioning end. In the assembly of the anchoring devices, the oblique prestressing tendons at the edge of the pavement panel pass through the through holes in the grooves and protrusions of the edge anchoring device and are then fixed to the grooves and protrusions by anchors.

[0031] The upper part of the bidirectional anchoring device is the anchoring end, and the lower part is the tensioning end. The width of the pavement slab is formed by connecting multiple bidirectional anchoring devices, ranging from 7 to 10 meters. The distance between the tensioning end of one device combination and the anchoring end of another device combination is the length of the pavement slab, ranging from 10 to 20 meters. The curing time for a pavement slab is 7 to 14 days.

[0032] The method of continuous tensioning of inclined prestressed tendons for pavement is applied in the pavement construction of airport runways or taxiways.

[0033] Example: To prepare for the construction of an 80-meter-long and 10-meter-wide aircraft taxiway, the anchoring device of this invention is first connected end-to-end to form a 10-meter assembly, and five such assemblies are arranged at 20-meter intervals. The upper part of each assembly is the anchoring end, and the lower part is the tensioning end. A first set of prestressing tendons is inserted into the through-hole of the first assembly, and one end of the first set of prestressing tendons is anchored to the anchoring end of the first assembly using an anchor. Then, the tendons are inserted diagonally through the through-hole of the second assembly in the opposite direction, and a second set of prestressing tendons is inserted into the through-hole of the second assembly, with one end of the second set of prestressing tendons anchored to the anchoring end of the second assembly using an anchor. A steel mesh is laid between the first and second assemblies. Concrete slab 1 is then poured at the notch at the anchoring end of the first assembly and between the first and second assemblies. After 7 days of curing, the concrete strength reaches the design standard. At 75% of the design strength, the first set of prestressing tendons is tensioned at the tensioning end of the second device assembly, and the other end of the tensioned first set of prestressing tendons is anchored to the tensioning end of the second device assembly using anchors. The third set of prestressing tendons is inserted into the through hole of the third device assembly, and one end of the third set of prestressing tendons is anchored to the anchoring end of the third device assembly using anchors. A steel mesh is laid between the second and third device assemblies, and then concrete is poured between the second and third device assemblies to form slab 2. After curing for 7 days, the concrete strength reaches 75% of the design standard. The second set of prestressing tendons is tensioned at the tensioning end of the third device assembly, and the other end of the tensioned second set of prestressing tendons is anchored to the tensioning end of the third device assembly using anchors. Slabs 3 to 4 are completed in sequence according to the above procedures. When pouring slab 4, concrete is also poured at the tensioning end of the fifth device assembly, so that the entire aircraft taxiway is completed.

[0034] Since there is no post-pouring strip, the overall construction period is simply the sum of the construction and maintenance days of each pavement panel. In contrast, the traditional method requires adding the construction and maintenance days of the post-pouring strip to the construction and maintenance days of each pavement panel. This achieves seamless connection between different pavement panel construction procedures, resulting in a qualitative leap in construction efficiency and significantly shortening the overall construction period. Furthermore, the integrated structural design enables bidirectional prestressing transfer and anchoring, and can also avoid early pavement damage caused by defects in the quality of the post-pouring strip, greatly improving the pavement's durability and operational safety, and fundamentally reducing later maintenance costs.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles and spirit of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for continuous tensioning of inclined prestressed tendons in pavement construction, characterized in that... The following steps are used: Step 1: Connect multiple bidirectional anchoring devices end to end to form a device assembly of the required length, and arrange them at equal intervals. The bidirectional anchoring device is a cuboid with two notches (1) on each side of its long side. One long side of the cuboid is the anchoring end, and the other long side is the tensioning end. The notch (1) is an inverted isosceles trapezoid. Each isosceles trapezoid has at least two oblique through holes (2) on its waist. The through hole (2) on the waist of the upper or lower isosceles trapezoid near the center of the cuboid is connected to the through hole (2) of the isosceles trapezoid in the opposite direction. The holes (2) are connected. The through holes (2) on the waist of the isosceles trapezoid near the two ends of the cuboid are connected to the end of the cuboid. There is a groove (3) on one short side of the cuboid and a protrusion (4) on the other short side corresponding to the size of the groove. The cuboids are connected in sequence by embedding the protrusion (4) of the next cuboid into the groove (3) of the previous cuboid. The through hole (2) on the waist of the isosceles trapezoid at one end of the previous cuboid is connected to the through hole (2) of the isosceles trapezoid at the end of the next cuboid in the opposite direction. Step 2: Insert the first set of prestressing tendons into the through hole of the previous device assembly and anchor one end of the first set of prestressing tendons to the tensioning end of the previous device assembly using an anchor. Then, insert the first set of prestressing tendons obliquely through the through hole of the next device assembly in the opposite direction. Insert the second set of prestressing tendons into the through hole of the next device assembly and anchor one end of the second set of prestressing tendons to the tensioning end of the next device assembly using an anchor. Step 3: Lay a steel mesh and pour concrete between the previous and next assembly to form a pavement panel; Step 4: When the pavement slab has been cured to 75% of its design strength, tension the first set of prestressing tendons. After tensioning, anchor the other end of the first set of prestressing tendons to the tensioning end of the next device assembly using anchors. Then, pass the second set of prestressing tendons obliquely through the through hole in the opposite direction on the third device assembly. Step 5: Repeat steps 3-4 to continuously pour and tension the prestressing tendons of multiple pavement panels until the entire pavement is completed.

2. The method for continuous tensioning of inclined prestressed tendons in pavement construction as described in claim 1, characterized in that: The groove and corresponding protrusion of the bidirectional anchoring device are both isosceles trapezoids with a base angle of 60°, and the base angle of the notch is 25°-45°.

3. The method for continuous tensioning of inclined prestressed tendons in pavement construction as described in claim 1, characterized in that: In the device assembly consisting of the bidirectional anchoring device, the oblique prestressing tendons at the edge of the pavement panel pass through the through holes in the grooves and protrusions of the anchoring device at the edge and are then fixed to the grooves and protrusions by anchors.

4. The method for continuous tensioning of inclined prestressed tendons in pavement construction as described in claim 1, characterized in that: The upper part of the bidirectional anchoring device is the anchoring end, and the lower part is the tensioning end. The device combination formed by connecting multiple bidirectional anchoring devices is the width of the pavement panel, which ranges from 7 meters to 10 meters. The distance between the tensioning end of one device combination and the anchoring end of another device combination is the length of the pavement panel, which ranges from 10 meters to 20 meters.

5. The method for continuous tensioning of inclined prestressed tendons in pavement construction as described in claim 1, characterized in that: The curing time for a single deck panel is 7-14 days.

6. The method for continuous tensioning of inclined prestressed tendons in pavement construction as described in claim 1, characterized in that: The aforementioned method for continuous tensioning of inclined prestressed tendons in pavement construction is applied to the pavement construction of aircraft runways or taxiways.

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