CN110644322A

CN110644322A - Municipal road construction method

Info

Publication number: CN110644322A
Application number: CN201910984025.2A
Authority: CN
Inventors: 吴小燕; 曹瓦; 常青平; 尹红; 邹进
Original assignee: Sichuan Qifeng Construction Engineering Co Ltd
Current assignee: Sichuan Qifeng Construction Engineering Co Ltd
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-01-03

Abstract

The invention relates to a municipal road construction method, which comprises the following steps: step 1, construction preparation and cement stabilized macadam subbase layer laying; step 2, paving a cement stabilized macadam base layer on the cement stabilized macadam subbase layer; step 3, paving the lower layer of the AC-25 asphalt on the cement stabilized macadam base layer through a paver; step 4, paving an AC-20C asphalt middle surface layer on the AC-25 asphalt lower surface layer through a paver; and 5, paving the upper layer of the fiber network composite enhanced high-elastic modulus asphalt on the middle layer of the AC-20C asphalt by a paver, wherein the three-dimensional flocculent particle mineral basalt fiber is added to the upper layer of the fiber network composite enhanced high-elastic modulus asphalt, so that the construction is completed. The invention has the effect of effectively improving the strength and toughness of the asphalt.

Description

Municipal road construction method

Technical Field

The invention relates to the technical field of road engineering, in particular to a municipal road construction method.

Background

With the increasing of road traffic volume, transportation vehicles gradually tend to be large-sized and heavy-loaded, and the phenomena of cracking, water loss and rutting appear in the asphalt concrete pavement too early, so that the service life of the asphalt concrete pavement generally does not reach the design level.

In the prior art, in order to improve the service performance and durability of an asphalt concrete pavement, a method of adding a modifier into an asphalt mixture is generally adopted at present,

the above prior art solutions have the following drawbacks: due to the limitation of the addition amount, the modifier modified asphalt has a limit on the effect of improving the performance of the asphalt pavement, can only improve the deformation of the pavement to a certain extent, and can not effectively solve the problems of high-temperature rutting resistance, low-temperature cracking resistance, water damage and the like of the asphalt pavement.

Disclosure of Invention

The invention aims to provide a municipal road construction method which has the advantages of effectively improving the strength and toughness of asphalt.

The above object of the present invention is achieved by the following technical solutions:

a municipal road construction method comprises the following steps:

step 1, construction preparation and cement stabilized macadam subbase layer laying;

step 2, paving a cement stabilized macadam base layer on the cement stabilized macadam subbase layer;

step 3, paving the lower layer of the AC-25 asphalt on the cement stabilized macadam base layer through a paver;

step 4, paving an AC-20C asphalt middle surface layer on the AC-25 asphalt lower surface layer through a paver;

and 5, paving the fiber network composite enhanced high-elastic modulus asphalt upper layer on the AC-20C asphalt middle layer by using a paver, wherein the three-dimensional flocculent particle mineral basalt fibers are added to the fiber network composite enhanced high-elastic modulus asphalt upper layer, so that the construction is completed.

By implementing the technical scheme, in the process of constructing the asphalt road, firstly, paving a cement stabilized macadam subbase layer, then paving a cement stabilized macadam base layer, then paving an AC-25 asphalt lower surface layer and an AC-20C asphalt middle surface layer from bottom to top, and finally paving a fiber network composite enhanced high-elasticity modulus asphalt upper surface layer, wherein the fiber network composite enhanced high-elasticity modulus asphalt upper surface layer is mainly formed by adding three-dimensional flocculent particle mineral basalt fibers in an SMA-13 asphalt mixture, the three-dimensional flocculent particle mineral basalt fibers can be better combined with asphalt to play roles of adsorption, stabilization, adhesion and reinforcement in the asphalt mixture, and can also be used as a carrier of the asphalt to increase the asphalt using amount and prevent the asphalt from losing so as to generate a composite modification effect, and the fibers and the structural asphalt adsorbed on the surface of the fibers form a space network structure among mineral materials, the finally paved fiber network composite enhanced high-elastic modulus asphalt upper surface layer has the advantages of better high-temperature stability and low-temperature crack resistance, aging speed delay, pavement performance and durability improvement of the pavement, and effective strength and toughness improvement of the asphalt.

The invention is further set that in the step 5, the diameter of the three-dimensional flocculent particle mineral basalt fiber is 5 mu m, the doping amount is 0.4 percent, and the optimal oilstone ratio is 6.0 percent.

By implementing the technical scheme, the mixing proportion is obtained by carrying out Marshall test on the mixed materials with different grades, so that a better construction effect can be achieved.

The invention is further set that in the step 5, after the upper layer of the fiber network composite enhanced high-elastic modulus asphalt is paved, three times of compaction of initial pressing, re-pressing and final pressing are required.

By implementing the technical scheme, the purpose of primary pressing is to level and stabilize the upper surface layer of the fiber network composite reinforced high-elastic modulus asphalt, and special attention needs to be paid to the flatness; the aim of re-pressing is to make the upper layer of the fiber network composite enhanced high-elastic modulus asphalt compact, stable and formed, and the compactness of the mixture is determined by the procedure; the purpose of final pressing is to eliminate the wheel tracks of the road roller and form a smooth compacted road surface.

The invention is further configured that in step 4, before the AC-20C asphalt middle surface layer is paved, a high-viscosity emulsified asphalt adhesive layer is sprayed on the AC-25 asphalt lower surface layer.

By implementing the technical scheme, the high-viscosity emulsified asphalt viscous layer is sprayed between the AC-25 asphalt lower surface layer and the AC-20C asphalt middle surface layer, so that the adhesion between the AC-25 asphalt lower surface layer and the AC-20C asphalt middle surface layer is enhanced.

The invention is further configured that in step 5, before paving the upper layer of the fiber network composite enhanced high-elastic modulus asphalt, a high-viscosity emulsified asphalt adhesive layer is sprayed on the middle layer of the AC-20C asphalt.

By implementing the technical scheme, the high-viscosity emulsified asphalt bonding layer is sprayed between the AC-20C asphalt middle surface layer and the fiber network composite enhanced high-elastic modulus asphalt upper surface layer, so that the bonding between the AC-20C asphalt middle surface layer and the fiber network composite enhanced high-elastic modulus asphalt upper surface layer is enhanced.

The invention is further set in that in the step 1, the cement stabilized macadam subbase layer is formed by paving and rolling cement stabilized macadam with the thickness of 20 cm.

Implement above-mentioned technical scheme, cement stabilized macadam subbase is spread by 20cm thick cement stabilized macadam and rolls and forms, can promote the bearing capacity of the lower shallow layer of ground of cement stabilized macadam subbase.

The invention is further set that the paving temperature of the upper surface layer of the fiber network composite enhanced high-elastic modulus asphalt is not lower than 165 ℃.

By implementing the technical scheme, because the three-dimensional flocculent mineral basalt fiber is added, the viscosity of the asphalt mucilage is increased, the fiber network composite enhanced high-elastic modulus asphalt upper surface layer is preferably carried out under the condition of higher air temperature, and the paving temperature is 5-10 ℃ higher than that of common asphalt concrete.

The invention is further arranged that before the material of the paver is received, an anti-adhesive agent is coated in the receiving hopper of the paver.

By implementing the technical scheme, in the process of receiving materials by the paver, in order to reduce the adhesion between the asphalt mixture and the hopper wall of the receiving hopper of the paver as much as possible, a proper amount of anti-adhesive is coated in the receiving hopper of the paver, so that the conditions of segregation, waves and the like in the paving process are avoided.

In conclusion, the invention has the following beneficial effects:

the fiber network composite enhanced high-elastic modulus asphalt upper layer is mainly characterized in that three-dimensional flocculent particle mineral basalt fibers are added in an SMA-13 asphalt mixture, the three-dimensional flocculent particle mineral basalt fibers can be better combined with asphalt, the adsorption, stabilization, adhesion and reinforcement effects are realized in the asphalt mixture, the asphalt dosage can also be increased as a carrier of the asphalt, the asphalt loss is prevented, and therefore a composite modification effect is generated, the fibers and structural asphalt adsorbed on the surfaces of the fibers form a space network structure between mineral aggregates, so that the finally paved fiber network composite enhanced high-elastic modulus asphalt upper layer has better high-temperature stability and low-temperature crack resistance, the aging speed is delayed, the pavement performance and durability of a pavement are improved, and the strength and toughness of the asphalt are effectively improved;

secondly, the purpose of primary pressing is to level and stabilize the upper surface layer of the fiber network composite reinforced high-elastic modulus asphalt, and the flatness needs to be paid special attention; the aim of re-pressing is to make the upper layer of the fiber network composite enhanced high-elastic modulus asphalt compact, stable and formed, and the compactness of the mixture is determined by the procedure; the purpose of final pressing is to eliminate the wheel tracks of the road roller and form a smooth compacted road surface. .

Drawings

FIG. 1 is a cross-sectional view of a town road according to an embodiment of the present invention.

Reference numerals: 1. a cement stabilized macadam sub-base; 2. a cement stabilized macadam base; 3. an AC-25 asphalt lower surface layer; 4. C-20C asphalt middle surface; 5. a fiber network composite enhanced high-elastic modulus asphalt upper surface layer; 6. high-viscosity emulsified asphalt adhesive layer.

Detailed Description

The technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings.

Examples

As shown in figure 1, a municipal road is sequentially paved with a cement stabilized macadam subbase layer 1, a cement stabilized macadam base layer 2, an AC-25 asphalt lower surface layer 3, an AC-20C asphalt middle surface layer 4 and a fiber network composite enhanced high-elastic modulus asphalt upper surface layer 5 from bottom to top. Simultaneously, before the AC-20C asphalt middle surface layer 4 is paved, a high-viscosity emulsified asphalt bonding layer 6 is sprayed on the AC-25 asphalt lower surface layer 3, so that the bonding between the AC-25 asphalt lower surface layer 3 and the AC-20C asphalt middle surface layer 4 is enhanced; before the fiber network composite enhanced high-elastic modulus asphalt upper surface layer 5 is paved, a high-viscosity emulsified asphalt bonding layer 6 is sprayed on the AC-20C asphalt middle surface layer 4, so that the bonding between the AC-20C asphalt middle surface layer 4 and the fiber network composite enhanced high-elastic modulus asphalt upper surface layer 5 is enhanced.

The embodiment also discloses a municipal road construction method, which comprises the following steps:

step 1, preparing materials and machinery before construction, and paving and rolling a cement stabilized macadam subbase layer 1 by using cement stabilized macadams with the thickness of 20 cm; mixing the cement stabilized macadam in a soil taking place, transporting to the site, paving by adopting an excavator in combination with a paver, and finely leveling by a land leveler; before paving, the lower cushion layer of the subbase layer is subjected to quality inspection and acceptance, all the floating soil, pumice and sundries are removed from the filled roadbed, and the subbase layer is shaped and compacted strictly according to the standard and design requirements;

step 2, constructing a cement stabilized macadam base layer 2 on the cement stabilized macadam subbase layer 1, wherein two pavers are adopted for full-width one-time paving, the speeds of the two pavers need to be kept at constant speed in the paving process, the two pavers are staggered and advance in tandem (about 5-10 m apart), and the time interval of paving a mixture on any adjacent working channel cannot exceed 25 min;

step 3, paving an AC-25 asphalt lower surface layer 3 on the cement stabilized macadam base layer 2, wherein two pavers are paved in a step shape when paving, the front and the back are staggered by 10 ~ 20m, the paving working surfaces of two adjacent pavers are overlapped by 5cm ~ 10cm, the width of the outer edge of a road is 5cm, and the compaction thickness of asphalt concrete is 8 cm;

step 4, thoroughly cleaning the surface of the AC-25 asphalt lower surface layer 3, removing soil sundries in grooves, uniformly spraying a high-viscosity emulsified asphalt adhesive layer 6 after air drying, carrying out traffic control after the high-viscosity emulsified asphalt adhesive layer 6 is sprayed, prohibiting any vehicle from passing and personnel from trampling, carrying out AC-20C asphalt middle surface layer 4 construction when wheels are not adhered, and arranging an automatic control device on a paver, wherein a cross slope controller can enable an ironing plate to keep an ideal gradient and can control elevation and flatness through a sensor, so that the paver can pave ideal longitudinal and cross slopes, and the error is within the range of 0.1%;

step 5, thoroughly cleaning the surface of an AC-20C asphalt middle surface layer 4, uniformly spraying a high-viscosity emulsified asphalt adhesive layer 6 after air drying, paving a fiber network composite enhanced high-elasticity modulus asphalt upper surface layer 5 on the AC-20C asphalt middle surface layer 4, properly increasing the vibration frequency of a rammer under a high-temperature state by using the fiber network composite enhanced high-elasticity modulus asphalt upper surface layer 5 to ensure the final flatness of the road surface, paving a single-width double-lane road surface by using a common paver, paving the road surface in a ladder formation by using 2 pavers, and paving a widening section by using a machine; the blanking speed and the advancing speed of the paver are adjusted according to the determined loose paving coefficient, in order to ensure the initial pressing effect of the ironing plate, the ironing plate is intermittently preheated half an hour in advance, two adjacent pavers are staggered by 10-30 m front and back to form trapezoidal operation, and the paving widths are overlapped by 10 cm. In the paving process, the paver paves, the transport vehicle unloads the paver, the transport vehicle leaves immediately after unloading, another vehicle continues unloading, and the paving temperature of the mixture is controlled to be not lower than 165 ℃;

step six, compacting the road surface, wherein the compacting is carried out through three processes of initial pressing, re-pressing and final pressing; the initial pressure is controlled at 1.5-2.0 km/h by a steel wheel roller, and the temperature is controlled at 110-130 ℃. After initial pressing, the flatness and the road arch are checked, and when the road surface is not flat, the road surface is repaired, if the road surface is rolled, the temperature of the mixture is too high, and the road surface is pressed again after the temperature is reduced; when re-pressing, firstly pressing twice by using a rubber-wheel road roller, then pressing twice by using a vibratory road roller, and after the re-pressing is finished, checking the pavement evenness by using a 3m straight ruler and making corresponding marks; before final pressing, the road roller adopts a proper treatment method according to the mark: if the transverse flatness has a problem, carrying out transverse strong vibration for 2-3 times, if the longitudinal flatness has a problem, carrying out longitudinal strong vibration for 2-3 times, and during final pressing, carrying out rolling for 2 times by using a rubber-tyred roller to eliminate the wheel track of the roller, wherein the final pressing temperature is controlled to be 80-90 ℃, and the compacting speed is controlled to be 2.5-3.5 km/h;

and seventhly, after the asphalt mixture is paved, traffic is closed in a maintenance period, a special person is set for maintenance, all vehicles are forbidden to pass, a warning board is set to prevent pedestrians from passing on the road surface and influencing the appearance effect of the road surface, and the traffic can be opened when the surface temperature of the asphalt concrete surface layer is naturally cooled to be lower than 50 ℃, so that the construction is completed.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. A municipal road construction method is characterized by comprising the following steps:

step 1, construction preparation is carried out, and a cement stabilized macadam subbase (1) is laid;

step 2, paving a cement stabilized macadam base layer (2) on the cement stabilized macadam subbase layer (1);

step 3, paving an AC-25 asphalt lower surface layer (3) on the cement stabilized macadam foundation (2) through a paver;

step 4, paving the AC-20C asphalt middle surface layer (4) on the AC-25 asphalt lower surface layer (3) through a paver;

and 5, paving the fiber network composite enhanced high-elastic modulus asphalt upper surface layer (5) on the AC-20C asphalt middle surface layer (4) by using a paver, wherein the three-dimensional flocculent particle mineral basalt fibers are added to the fiber network composite enhanced high-elastic modulus asphalt upper surface layer (5), so that the construction is completed.

2. The town road construction method according to claim 1, wherein in step 5, the diameter of the basalt fiber of the three-dimensional flocculent grain mineral is 5 μm, the doping amount is 0.4%, and the optimum oilstone ratio is 6.0%.

3. The method for constructing the municipal road according to claim 1, wherein in step 5, the fiber network composite reinforced high elastic modulus asphalt upper surface layer (5) needs to be compacted by three times of initial pressing, secondary pressing and final pressing after being paved.

4. The method of claim 1, wherein in step 4, the high-viscosity emulsified asphalt binder layer (6) is sprayed on the AC-25 asphalt lower surface layer (3) before the AC-20C asphalt middle surface layer (4) is paved.

5. The municipal road construction method according to claim 1, wherein in step 5, the high-viscosity emulsified asphalt binder layer (6) is sprayed on the AC-20C asphalt middle surface layer (4) before the fiber network composite reinforced high-elastic modulus asphalt upper surface layer (5) is paved.

6. The method of claim 1, wherein in step 1, the cement stabilized macadam underlayment (1) is formed by paving and rolling 20cm thick cement stabilized macadam.

7. The town road construction method according to claim 1, wherein the paving temperature of the fiber network composite reinforced high elastic modulus asphalt upper surface layer (5) is not lower than 165 ℃.

8. The municipal road construction method according to claim 1, wherein the anti-adhesive is applied to a receiving hopper of the paver before the paver receives the material.