CN204662193U - Oblique prestressing force cement concrete-bituminous concrete composite pavement - Google Patents

Abstract

The oblique prestressed cement concrete-asphalt concrete composite pavement includes an oblique prestressed cement concrete layer arranged on the base layer, an asphalt concrete layer is arranged on the oblique prestressed cement concrete layer, and the oblique prestressed cement concrete layer and An adhesive layer is arranged between the asphalt concrete layers. The composite pavement is suitable for paving on heavy-duty traffic roads; the surface layer uses asphalt concrete, which not only improves the comfort of the road surface, reduces the noise of vehicles running, but also reduces the stimulation of light to the driver's vision when the vehicle is running. In addition, the utility model improves the strength of the cement concrete slab, prolongs the service life of the road, reduces maintenance costs, and the average annual cost in the entire service life is lower than that of other road surfaces.

Description

Oblique Prestressed Cement Concrete-Asphalt Concrete Composite Pavement

technical field

The utility model relates to a pavement structure, in particular to an oblique prestressed cement concrete-asphalt concrete composite pavement.

Background technique

With the development of the national economy, my country's highway construction has achieved remarkable achievements. By the end of 2013, the total mileage of highways in my country had reached 4,356,200 kilometers, of which the mileage of expressways had reached 104,400 kilometers, ranking first in the world, marking that my country's expressway construction has entered a period of comprehensive and rapid development.

According to the statistics of the competent department of transportation, asphalt pavement mileage accounts for more than 90% of the expressways that have been built and are under construction. The reason is that asphalt pavement has great advantages over traditional cement concrete pavement, such as: asphalt pavement surface Smooth and seamless, good driving comfort; two-pole shock absorption between the wheel and the road surface, small vibration and low noise; short construction period, fast open traffic; asphalt road surface does not raise dust, is easy to clean, and is easy to maintain in the later period; recyclable, suitable Phased construction, etc.

Although the asphalt pavement has the above advantages, with the development of modern transportation, the phenomenon of road overloading is increasing, and many problems in the asphalt pavement are gradually exposed: various diseases such as rutting, water damage, aging cracks, etc.; Less than the design life; too much investment and so on.

The expressway construction in the new era gradually transitions from the original eastern plain area to the western mountainous area. Due to the special landform of the mountainous area, there will be more bridges, tunnels and other structures in the process of highway construction, which often brings new problems to expressway construction. Many inconveniences, such as the road section between bridge structures with a distance of only tens of meters or even less, if the upper, middle and lower surface courses are paved according to the conventional design, it will often cause the road roller to be too far away from the bridge abutment during layered compaction. Nearly, it is easy to damage the bridge structure, or the road roller cannot turn around, resulting in problems such as insufficient road compaction, which leads to poor durability of the road structure and cannot reach the designed service life, resulting in high post-maintenance costs.

Utility model content

In order to overcome the problems in the prior art, the purpose of this utility model is to provide oblique prestressed cement concrete-asphalt concrete composite pavement. The pavement structure is a composite pavement structure. Low.

In order to achieve the above object, the technical scheme adopted by the utility model is as follows:

The oblique prestressed cement concrete-asphalt concrete composite pavement includes an oblique prestressed cement concrete layer arranged on the base layer, an asphalt concrete layer is arranged on the oblique prestressed cement concrete layer, and the oblique prestressed cement concrete layer and An adhesive layer is arranged between the asphalt concrete layers.

The thickness of the oblique prestressed cement concrete layer is 22-26 cm.

The thickness of the bonding layer is 0.5-1 cm.

The thickness of the asphalt concrete layer is 4-6 cm.

The construction method of oblique prestressed cement concrete-asphalt concrete composite pavement, first pave a layer of 22-26cm oblique prestressed cement concrete on the base of the pavement, after forming the oblique prestressed cement concrete layer, and then lay the oblique After milling the surface of the prestressed cement concrete layer, spread a layer of adhesive layer with a thickness of 0.5-1cm on the surface of the oblique prestressed cement concrete layer, and pave a layer of 4-6cm asphalt concrete on the adhesive layer to form asphalt concrete. layer.

The bonding layer is sealed with rubber asphalt synchronously with crushed stones, and the asphalt is sprayed and scattered with crushed stones by a crushed stones sealer.

The speed of the gravel sealer is 1.5-2km/h, the asphalt spreading rate is 1.69-1.71kg/m ² , the bitumen spreading temperature is 180-190°C; the crushing rate is 7kg/m ² , the The stone spreading temperature is 130°C.

The particle size of the gravel is 4.75-9.5mm.

When paving a layer of 22-26cm oblique prestressed cement concrete, the angle between the arrangement angle of oblique prestressed steel bars and the longitudinal direction of the road is 30°-45°, and the angle is 1cm below the middle of the concrete thickness. Arranged oblique prestressed reinforcement.

When paving a layer of 22-26cm oblique prestressed cement concrete, the prestress is applied twice, and the first time is applied after 3 days of concrete paving, and the applied strength is 30% of the yield strength of the steel bar; Apply the second time after 7 days of construction, and the applied strength is 70% of the yield strength of the steel bar.

Compared with the prior art, the utility model patent has beneficial effects:

(1) Give full play to the characteristics of combining rigidity and softness, and improve the ability to adapt to heavy loads.

The composite pavement of the utility model is a rigid-flexible composite pavement. Since the oblique prestressed cement concrete layer and the asphalt concrete layer are set, the characteristics of two different pavement materials can be fully utilized, and the strengths of materials and structures can be used to form a soft yet rigid road. , rigid and flexible pavement structure; due to the high strength of oblique prestressed concrete, it can bear most of the stress transmitted by the surface layer, so this composite pavement is suitable for paving heavy-duty traffic roads; the surface layer uses asphalt concrete, which not only makes the pavement The comfort is improved, the noise of the vehicle is reduced, and at the same time, the stimulation of the light to the driver's vision can be weakened during the driving of the vehicle.

(2) Save the cost and prolong the service life of the road.

In the utility model, oblique prestressed concrete is used for the lower layer, and the construction technology and quality standards of the concrete slab can be appropriately reduced, such as performance indicators such as flatness and skid resistance, and the asphalt surface layer can provide better performance and reduce engineering costs. Cost: Although the addition of prestressed steel bars increases part of the cost, it also improves the strength of the cement concrete slab, prolongs the service life of the road, and reduces maintenance costs. The average annual cost during the entire service life is lower than other road surfaces.

(3) It is easy to maintain and repair, and has environmental protection significance.

The composite pavement provided by the utility model has high strength and strong bearing capacity, so in the whole life cycle, diseases are not easy to occur, and the number of repairs is less than that of other pavements, which reduces the later maintenance cost.

(4) According to local conditions, it is suitable for special loess landform areas.

The composite pavement of the utility model is especially suitable for road sections connecting structures such as bridges and culverts with small distances, that is, short-circuit foundation road sections. Co-deformability of road surfaces.

Furthermore, because the asphalt concrete layer on the surface of the composite pavement is thin, only 4-6 cm, the amount of asphalt used can be reduced. At the same time, the durability of the asphalt layer is less than that of the oblique prestressed concrete layer. Generally, the asphalt layer is destroyed first, and only the surface layer needs to be removed. Excavation, the mixed oblique prestressed concrete layer basically does not need to be processed to pave a new surface layer, and the maintenance is very convenient and quick. At the same time, it saves asphalt material compared with asphalt concrete pavement, and reduces the pollution of cement to the environment compared with cement concrete pavement, so it has good social benefits and environmental protection significance.

Description of drawings

Fig. 1 is the overall structure diagram of the present utility model.

Among them, 1-asphalt concrete layer, 2-adhesive layer, 3-oblique prestressed cement concrete layer, 4-base layer.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described.

As shown in Figure 1, the utility model comprises an oblique prestressed cement concrete layer 3 arranged on the base layer 4, an asphalt concrete layer 1 is arranged on the oblique prestressed cement concrete layer 3, and the oblique prestressed cement concrete layer 3 and the asphalt concrete layer 1 are provided with an adhesive layer 2, the thickness of the oblique prestressed cement concrete layer 3 is 22 to 26 cm, and the oblique prestressed cement concrete layer 3 is milled and sprinkled with 0.5 to 1 cm of adhesive The binding layer 2 and the adhesive layer 2 are sealed with rubber asphalt synchronous gravel, and then a 4-6 cm thick asphalt concrete layer 1 is paved on the adhesive layer 2 to form a composite pavement structure.

Generally, the asphalt pavement structure of ordinary highways is divided into soil base, subbase, upper base, lower layer, middle layer and upper layer from bottom to top. The composite pavement structure of the utility model is to pave a layer of 22-26cm thick oblique prestressed cement concrete layer on the base layer. The included angle is 30°～45°, and it is arranged at a position 1cm below the middle of the concrete thickness. The prestress is applied twice, the first time is applied 3 days after the concrete is laid, and the applied strength is about 30% of the yield strength of the steel bar, and the second time is 7 days after the concrete is laid, the applied strength is 70% of the steel bar's yield strength. After that, the concrete surface is milled and planed, and then the pavement is cleaned and sprinkled with a layer of bonding layer with a thickness of 0.5-1cm, and then a 4-6cm asphalt concrete layer is paved on it to form a rigid-flexible composite pavement structure.

The construction method of the present utility model is specifically as follows: firstly, on the base layer 4 of the pavement, a layer of 22-26 cm oblique prestressed cement concrete is first paved to form an oblique prestressed cement concrete layer 3, and a layer of 22-26 cm is paved. The specific construction process of oblique prestressed cement concrete is as follows:

1. Set up the template and place the U-shaped board

The base layer is lean concrete, and rigid formwork is used. The bottom surface of the formwork is closely attached to the top surface of the base layer, and the local low-lying places are paved with cement mortar in advance. After the formwork is installed, check the height difference at the joint and whether there is any misalignment inside the formwork. The height difference at the joint is controlled within 3mm. Since the reserved length of the prestressed tendon is generally 40-60cm, the ordinary steel form cannot guarantee the penetration of the prestressed tendon, so the formwork will have an open slot at a certain distance, which is to place the fixed frame plate and the fixed frame plate It must be placed correctly without large deviations. If there is a large deviation, the position of the steel bars on the same level will be uneven, and the force will be uneven after tensioning.

2. Lay the sliding layer

The laying of the sliding layer should comply with the provisions of the "Technical Code for Prestressed Concrete Pavement Engineering" GB50422-2007. The sliding layer is set on the top surface of the base, and the base should be flat without pits. The material of the sliding layer can be selected from geotextile, felt, polyethylene film or fine-grained material, and the fine-grained material can be selected from fine sand or stone chips with similar particle size. When fine-grained materials are used to lay the sliding layer, the thickness of fine-grained materials should not be greater than 20mm, and waterproof materials should be laid on it. In the utility model, the test section is laid with a 1cm thick sand layer (diameter is less than 0.3mm), and a layer of polyethylene film is laid on the sand layer to play the role of leveling and less friction. Among them, the leveling of the base layer and the integrity of the polyethylene film are the key to this technology. It is also important to remove the small stones in the sand layer and make the film contact with the fine sand as much as possible without bulging.

3. Lay out structural steel bars

Arrange a row of structural steel bars on each side of the road width. The purpose is to reinforce the strength around the road with steel bars. The other function is to prevent prestressing from being applied near the bridge abutment. One end is fixed with concrete. The other end of the steel bar is prestressed so that it can achieve the required force.

4. Wearing tendons and straightening prestressed tendons

The steel bar of construction in the utility model is the smooth round steel bar of 10mm in diameter, and the prestressed tendon of calculated length is passed through fixing frame, and the included angle of 45 degree is with the roadway direction. Divided into two road construction, the purpose is not to interrupt the traffic. The prestressed tendons are bidirectionally crossed. The distance between two adjacent steel bars longitudinally along the pavement is 50cm. After the prestressed steel bars are arranged, they need to be straightened to ensure that the steel bars are perpendicular to the fixed frame plate.

5. Fixed horse stool

The horse stool is made by bending both sides with a short steel bar, which can stand on the sliding layer to support the prestressed tendons. The height of the horse stool is determined by the height of the prestress. The concrete thickness of the test section in the utility model is 24cm, and the height of the horse stool is determined to be 1cm less than half of the thickness of the concrete, and the height is 11cm. The horse stool is made by a bending and drawing steel bar machine, and then the horse stool is tied with a small steel wire. At the intersection of prestressed tendons, the prestressed tendons are in the middle, and a certain height can also be maintained to ensure that the damage to the concrete is reduced when the prestress is stretched in the future, and the prestressed tendons are avoided when pouring concrete.

6. Apply anti-corrosion grease

After the horse stool is fixed, the anti-corrosion grease painting needs to be painted manually, which is troublesome and requires a lot of manpower to ensure that every corner can be painted. The purpose of painting anti-corrosion grease is to isolate the future prestress from water, not easy to corrode, and make the life of the prestress cement concrete pavement longer.

7. Pouring concrete

Because the pavement of the test section needs to be paved successfully in one go, but the strength and difficulty of concrete paving are increased due to the existence of steel mesh. The paving process is to transfer the cement concrete transported by the concrete mixer truck to the paving position by mobilizing the hopper by the crane, and then pull the vibrating beam forward, and fill the uneven part with iron brazing. During the pouring process, a vibrating rod must be used to compact the concrete. When vibrating the concrete, the movement of the formwork must be prevented, and the operator is strictly prohibited from stepping on the prestressed tendons at will, so as to avoid the deviation of the prestressed position and ensure the integrity of the prestressed concrete.

8. Maintenance

After the concrete panels are constructed, they are covered with a water-sprinkled cover film to reduce the possibility of early shrinkage cracking. It needs to be watered evenly every day. Keep the road surface wet. After the curing period is 2 weeks, the mulch is removed and the traffic can be opened.

9. Formwork removal and tension prestressing

One day after the concrete was formed, the formwork was disassembled, and then the prestressed tendons were stretched. In order to ensure that the concrete long slabs did not shrink and crack before prestressing, the prestressed tendons were stretched twice. The sequence of tensioning is carried out sequentially from one end of the pavement to the other. Two jacks are used for symmetrical tensioning at the same time. If both sides cannot be tensioned at the same time, one side of the tension must be stretched. Every prestressed tendon must be stretched. The force of the first tension is 30% of the total stress. , After 7 days of curing, the second stretching is carried out, and the second stretching can reach 70% of the total stress. During the tensioning process, the size of the Kong’s tension force and the speed of the force must be strictly controlled to ensure that the prestress will not be broken.

The construction process must comply with the "Technical Specifications for Cement Concrete Pavement Construction" (JTG F30-2003), "Technical Specifications for Highway Subgrade Construction" (JTG F10-2006), "Technical Specifications for Prestressed Concrete Pavement Engineering" (GB50422-2007) and other specifications relevant regulations.

After the oblique prestressed cement concrete layer 3 is formed, the surface of the oblique prestressed cement concrete layer 3 becomes rough by surface milling. 3 Sprinkle a layer of adhesive layer 2 with a thickness of 0.5-1cm on the surface. The adhesive layer 2 uses rubber asphalt synchronous crushed stone seal layer, and uses an intelligent crushed stone sealer to spray rubber asphalt and spread aggregates. The speed is generally controlled at 1.5 ~2km/h or less. The spreading amount of rubber asphalt should be controlled at 1.7kg/m ² (floating range ±0.1), the asphalt spreading temperature should be 180-190°C, the aggregate should be crushed stones of 4.75-9.5mm, and the spreading amount of aggregate should be 7kg/m ² . The spreading temperature of the aggregate is controlled at about 130°C. In this way, uniform asphalt spreading and crushed stone coverage (70% to 80%) can be guaranteed, excessive spraying of asphalt or leakage, overlapping or blackened gravel spreading, etc. can be avoided, and the construction quality can be guaranteed fundamentally.

Then pave a layer of 4-6cm asphalt concrete on the bonding layer 2, and the asphalt concrete must be paved in strict accordance with the requirements of "Technical Specifications for Construction of Highway Asphalt Pavement" (JTG F40-2004). Carry out compaction molding then, finally form asphalt concrete layer 1, then the pavement structure that forms now is the composite pavement of the present utility model, i.e. oblique prestressed cement concrete-asphalt concrete composite pavement (CPC-AC: Cross-tensioned Prestressed Concrete-Asphalt Concrete).

Claims (4)

1. The oblique prestressed cement concrete-asphalt concrete composite pavement is characterized in that it includes an oblique prestressed cement concrete layer (3) arranged on the base (4), and an oblique prestressed cement concrete layer (3) is provided There is an asphalt concrete layer (1), and an adhesive layer (2) is arranged between the oblique prestressed cement concrete layer (3) and the asphalt concrete layer (1). 2. The oblique prestressed cement concrete-asphalt concrete composite pavement according to claim 1, characterized in that the thickness of the oblique prestressed cement concrete layer (3) is 22-26 cm. 3. The oblique prestressed cement concrete-asphalt concrete composite pavement according to claim 1, characterized in that the thickness of the bonding layer (2) is 0.5-1 cm. 4. The oblique prestressed cement concrete-asphalt concrete composite pavement according to claim 1, characterized in that the thickness of the asphalt concrete layer (1) is 4-6 cm.