阅读说明：本技术 一种路面结构及其施工方法 (Pavement structure and construction method thereof ) 是由 邹红 李再春 吴剑波 朱清水 梅建军 于 2020-11-26 设计创作，主要内容包括：本发明公开了一种路面结构,其包括从下到上依次分布的水稳层、碎石封层、下面层和上面层,其特征在于,所述水稳层设置有横向延伸的凹槽,所述凹槽内填充有弹性密封条；所述凹槽和所述弹性密封条的上方覆盖有土工布,所述土工布在纵向上的宽度为0.5-2m,所述土工布在所述水稳层和碎石封层之间；所述下面层和所述上面层之间还设置有土工格栅,所述土工格栅在纵向上的宽度为1-3m,所述土工格栅位于所述土工布的上方。本发明还涉及该路面结构的施工方法。本发明缩短了施工周期,节省了部分人工费用与机械滞留费用,水稳层本身不规则裂缝也大量减少。同时,凹槽处上方沥青路面处并无反射裂缝,效果较佳,具备较大推广价值。(The invention discloses a pavement structure, which comprises a water stabilizing layer, a gravel sealing layer, a lower surface layer and an upper surface layer which are sequentially distributed from bottom to top, and is characterized in that the water stabilizing layer is provided with a transversely extending groove, and an elastic sealing strip is filled in the groove; geotextile covers the grooves and the elastic sealing strips, the width of the geotextile in the longitudinal direction is 0.5-2m, and the geotextile is arranged between the water stabilizing layer and the gravel sealing layer; and a geogrid is further arranged between the lower surface layer and the upper surface layer, the width of the geogrid in the longitudinal direction is 1-3m, and the geogrid is positioned above the geotextile. The invention also relates to a construction method of the pavement structure. The invention shortens the construction period, saves part of labor cost and mechanical retention cost, and greatly reduces the irregular cracks of the water stabilization layer. Meanwhile, the asphalt pavement above the groove is not provided with reflection cracks, the effect is better, and the method has great popularization value.)

1. A pavement structure comprises a water stabilizing layer (1), a gravel seal layer, a lower surface layer (2) and an upper surface layer (3) which are sequentially distributed from bottom to top, and is characterized in that the water stabilizing layer (1) is provided with a transversely extending groove (4), and the groove (4) is filled with an elastic sealing strip (5); geotextile (6) covers the grooves (4) and the elastic sealing strips (5), the width of the geotextile (6) in the longitudinal direction is 0.5-2m, and the geotextile (6) is arranged between the water stabilizing layer (1) and the gravel sealing layer; still be provided with geogrid (7) between lower surface course (2) and upper surface course (3), geogrid (7) are in vertical width 1-3m, geogrid (7) are located the top of geotechnological cloth (6).

2. A pavement structure according to claim 1, characterized in that said elastic sealing strip (5) is made of asphalt or sealant.

3. A pavement structure according to claim 1, characterized in that said grooves (4) are arranged at intervals of 25-50m in the longitudinal direction.

4. A pavement structure according to claim 1, characterized in that said grooves (4) have a width in the longitudinal direction of 3-8 mm; the depth of the groove (4) is 0.25-0.5 times of the thickness of the water stabilizing layer (1).

5. A pavement structure according to claim 1, characterized in that the geotextile (6) is connected with steel nails (8) at both longitudinal sides, and the steel nails (8) are fixed in the water-stable layer (1) after penetrating the iron sheet (9).

6. A pavement structure according to claim 1, characterized in that said geogrid (7) is fixedly connected to said lower layer (2) at both longitudinal sides thereof.

7. A pavement structure according to claim 1, characterized in that said geotextile (6) has a width in longitudinal direction of preferably 80-120 cm.

8. A pavement structure according to claim 1, characterized in that said geogrid (7) has a longitudinal width of preferably 100 and 160 cm.

9. A construction method of a pavement structure as claimed in any one of claims 1 to 8, comprising mainly the steps of:

1) after the construction of the water stabilization layer (1) is finished, a transversely extending groove (4) is formed in the water stabilization layer (1);

2) elastic sealing strips (5) are filled in the grooves (4);

3) covering the geotextile (6) above the groove (4) and the elastic sealing strip (5), and fixing the geotextile (6) on two sides in the longitudinal direction to the water stabilizing layer (1);

4) spreading penetrating layer oil and a gravel seal layer, and then constructing a lower surface layer (2); after the lower surface layer (2) is constructed, fixing a geogrid (7) on the lower surface layer (2), wherein the geogrid (7) is positioned above the geotextile (6);

5. and constructing an upper surface layer (3).

10. A pavement structure according to claim 9, characterized in that said strip (5) is asphalt, and said groove (4) is preheated by a hot air gun before applying asphalt into said groove (4).

Technical Field

The invention relates to a pavement structure and a construction method thereof, belonging to the technical field of asphalt concrete pavements and construction.

Background

The water-stable layer belongs to a semi-rigid base layer structure, and is commonly used in the construction of roads with more than two levels in China. In the construction process of the water stabilization base layer, because the self material has a certain dry shrinkage phenomenon (non-load effect) and the frequent effect (load effect) of construction vehicles and the like, a large amount of cracks, transverse and longitudinal seams and other diseases (shown in figures 1-2) appear in the water stabilization layer inevitably, and finally the rigidity of the water stabilization layer is reduced and the bearing capacity is reduced. Meanwhile, various cracks reflected to the oil surface layer not only reduce the comfort of vehicle running and the road surface aesthetic degree, but also increase the maintenance cost of the road surface at the later stage and reduce the running quality and the economic benefit of the road.

At present, researchers carry out a great deal of research work around the water-stable layer crack treatment, and the overall research work is summarized into two types of methods: firstly, considering the material of the water-stable layer, the material with larger drying shrinkage is used as little as possible, and the mixing proportion of the water-stable mixture is improved; however, the method greatly increases the cost and has higher economic cost. After the water stabilization period is finished, directly repairing the upper-layer water-stabilized cracks; this practice is often difficult during field operations due to the effect of construction period.

Disclosure of Invention

The invention provides a pavement structure and a construction method thereof, aiming at overcoming the technical problems of pavement cracking and the like caused by the material characteristics of a water stabilization layer, and the specific technical scheme is as follows.

A pavement structure comprises a water stabilizing layer, a gravel sealing layer, a lower surface layer and an upper surface layer which are sequentially distributed from bottom to top, and is characterized in that the water stabilizing layer is provided with a transversely extending groove which is filled with an elastic sealing strip; geotextile covers the grooves and the elastic sealing strips, the width of the geotextile in the longitudinal direction is 0.5-2m, and the geotextile is arranged between the water stabilizing layer and the gravel sealing layer; and a geogrid is further arranged between the lower surface layer and the upper surface layer, the width of the geogrid in the longitudinal direction is 1-3m, and the geogrid is positioned above the geotextile.

By adopting the technical scheme, the arrangement of the grooves is favorable for enabling the water stabilization layer structure to generate the most possible concentrated free deformation, the concentrated deformation is balanced through the elastic sealing strips, the geotextile and the geogrids, and the occurrence of the road surface cracking caused by the shrinkage deformation of the water stabilization layer is inhibited to the greatest extent. The longitudinal direction refers to a direction in which a road surface extends, and the lateral direction refers to a width direction of the road surface.

Furthermore, the elastic sealing strip is made of asphalt or sealant.

Further, the grooves are arranged at intervals of 25-50m in the longitudinal direction.

Further, the groove has a width in the longitudinal direction of 3 to 8 mm. The depth of the groove is 0.25-0.5 times of the thickness of the water stabilizing layer.

Furthermore, the two side parts of the geotextile in the longitudinal direction are connected with steel nails, and the steel nails penetrate through the iron sheet and the geotextile and are fixed in the water stabilizing layer.

Further, both sides of the geogrid in the longitudinal direction are fixedly connected with the lower layer.

Further, the width of the geotextile in the longitudinal direction is preferably 80 to 120 cm. The width of the geogrid in the longitudinal direction is preferably 100-160 cm.

Based on the same inventive concept, the invention also relates to a construction method of the pavement structure, which mainly comprises the following steps:

1) after the construction of the water stabilization layer is finished, a transversely extending groove is formed in the water stabilization layer;

2) filling elastic sealing strips into the grooves;

3) covering the groove and the elastic sealing strip with geotextile, and fixing two sides of the geotextile in the longitudinal direction on the water stabilizing layer;

4) spreading penetrating layer oil and a gravel seal layer, and then constructing a lower surface layer; after the lower surface layer is constructed, fixing a geogrid on the lower surface layer, wherein the geogrid is positioned above the geotextile;

5. and constructing an upper surface layer.

Further, the elastic sealing strip is asphalt, and the groove is preheated by a hot air spray gun before the asphalt is applied into the groove.

Compared with the prior art, the invention has the following beneficial effects.

1. The construction process flow is simple, and the operation is convenient; the water stable crack can be obviously eliminated or inhibited.

2. Can pave at the water stabilization layer and roll the very first time after and set up the recess, can reduce the time limit for a project to a certain extent.

Compared with the existing water-stable crack treatment method (changing the material mixing ratio and directly repairing cracks), the scheme of the invention has the advantages of very low cost per square meter of pavement and higher construction efficiency.

Drawings

FIG. 1 is a schematic illustration of a pavement structure of the present invention;

fig. 2 is an enlarged schematic view of region a in fig. 1.

In the figure: the water stabilizing layer 1, the lower surface layer 2, the upper surface layer 3, the groove 4, the elastic sealing strip 5, the geotextile 6, the geogrid 7, the steel nails 8 and the iron sheet 9.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

Referring to fig. 1-2, a pavement structure comprises a water stabilizing layer 1, a gravel seal layer (not shown), a lower surface layer 2 and an upper surface layer 3 which are sequentially distributed from bottom to top, wherein the water stabilizing layer 1 is provided with a transversely extending groove 4, and the groove 4 is filled with an elastic sealing strip 5; the upper parts of the grooves 4 and the elastic sealing strips 5 are covered with geotextile 6, the width of the geotextile 6 in the longitudinal direction is 0.5-2m, and the geotextile 6 is arranged between the water stabilizing layer 1 and the gravel sealing layer; a geogrid 7 is further arranged between the lower layer 2 and the upper layer 3, the width of the geogrid 7 in the longitudinal direction is 1-3m, and the geogrid 7 is located above the geotextile 6.

Wherein the grooves 4 are arranged at a distance of 25-50m, preferably 30m, in the longitudinal direction. The width of the groove 4 in the longitudinal direction is 3-8mm, preferably 5 mm; the depth of the groove 4 is 0.25-0.5 times of the thickness of the metastable layer, preferably 1/3 times of the thickness of the metastable layer. The width of the geotextile in the longitudinal direction is preferably 80 to 120 cm. The width of the geogrid in the longitudinal direction is preferably 100-160 cm.

Wherein, for fixed geotechnological cloth 6, geotechnological cloth 6 all is connected with steel nail 8 in vertical both sides portion, and steel nail 8 runs through behind iron sheet 9 and the geotechnological cloth 6 and is fixed in the water stable layer 1. Similarly, the two longitudinal sides of the geogrid 7 can be fixedly connected with the lower layer 2 through fasteners such as steel nails.

The elastic sealing strip can be made of asphalt. The common matrix asphalt is a good cementing material, has good bonding property and excellent water resistance, can have good fluidity and wettability when being heated to 160 ℃ of 140-. Meanwhile, the hot asphalt has the lowest cost and stable quality. The constructors have the most abundant experience on the preparation and use of the hot asphalt.

The elastic sealing strip can also adopt sealant which has good cohesiveness, low-temperature elastic flexibility and thermal stability and is close to an ideal elastomer, and the water stabilization layer 1 can provide a larger free deformation space for the water stabilization layer in the environment of expansion with heat and contraction with cold. Meanwhile, the water resistance, the embedding resistance and the aging resistance of the sealant are all inferior to those of hot asphalt. Compared with the hot asphalt comprehensively, the sealant has longer service life and more benefit than the hot asphalt.

The construction method of the pavement structure mainly comprises the following steps:

1) after the construction of the water stabilization layer 1 is completed, a transversely extending groove 4 is formed in the water stabilization layer 1;

2) elastic sealing strips are filled in the grooves 4;

3) covering the geotextile 6 above the groove 4 and the elastic sealing strip 5, and fixing the geotextile 6 on two sides in the longitudinal direction of the geotextile 1;

4) spreading penetrating layer oil and a gravel seal layer, and then constructing a lower surface layer 2; after the lower surface layer 2 is constructed, fixing a geogrid 7 on the lower surface layer 2, wherein the geogrid 7 is positioned above the geotextile 6;

5. and constructing an upper surface layer 3.

By adopting the construction method, the deformation of the water stabilization layer 1 is actively concentrated near the groove 4, and then the deformation of the water stabilization layer 1 is digested and absorbed through the geotextile 6 and the geogrid 7, so that various cracks caused by the reflection of the deformation of the water stabilization layer to the oil surface layer are prevented.

One embodiment is described in detail below

The pavement structure is implemented as follows.

1. Construction lofting

After the cement stabilized layer 1 is paved and rolled for 1 day (when the cement stabilized base layer is not influenced by loads of pedestrians and the like), lofting measurement is carried out by taking 30m as a reference, and white lime lines are scattered on the left and right sides by using steel rods for fixing points.

2. Making transverse grooves

The water stabilizing layer can be subjected to groove processing by using a cutting machine, the groove is 1/3 of the thickness of the water stabilizing layer, and the width of the groove is 5 mm. And (3) cleaning sundries such as small stones, stone powder and the like in the groove after the groove is machined (a high-pressure air pump or a steel brush and the like can be used).

3. Groove filling

The groove is cleaned by adopting an air compressor matched with a brush, and then the groove is preheated by a hot air spray gun, so that on one hand, the preheating can evaporate the water in the water-stable layer around the groove to form a dry combined surface; on the other hand, the heat generated by the hot air spray gun can instantly heat the water stabilization layer, so that the hot-melt asphalt material and the groove form a thermal contact effect, and the adhesion between the water stabilization layer and the asphalt material is increased.

4. Geotextile fixation

The width of the geotextile laid above the groove is 1m (within 50cm of each of two sides of the groove). The anchoring method is adopted for construction, constructors must wear gloves, and the construction process mainly comprises two steps:

A. the steel sheet with the thickness of 50mm multiplied by 30mm multiplied by 1mm (the steel sheet is required to be flat without corner rising, and the periphery is suitable for chamfering treatment) is matched with a 2-inch steel nail for fixing, one end of the steel sheet and the steel nail are fixed on the water stabilizing layer, and the steel nail can be shot in by hammering or a shooting gun. Then the geotextile is longitudinally tensioned, longitudinally and transversely positioned in a straight tensioning state and fixed, and the iron sheet compresses the geotextile. After the fixing, if the steel nail is broken or the iron sheet is loosened, the steel nail needs to be fixed again.

B. The length of the geotextile is not less than the extension length of the groove, and the geotextile should be laid smoothly and tensioned.

5. Spreading penetrating layer oil and chip seal

The asphalt is transported to a production workshop and then stored in an automatic heating storage tank, the temperature is automatically controlled by a computer, the temperature of the asphalt is heated to 185 +/-5 ℃ before construction, and a manual thermometer is combined for detection so as to check the accuracy of the asphalt.

After the asphalt is pumped into an asphalt storage tank of the synchronous chip sealer, the asphalt is subjected to heat preservation and heating by a heating device of the synchronous chip sealer so as to ensure the spreading temperature of the rubber asphalt.

After the synchronous gravel sealing vehicle filled with asphalt and gravel is driven to a construction site, the spraying amount of asphalt and the spreading amount of gravel are accurately set on a computer.

Construction can be started after the position of the synchronous chip sealer is accurately adjusted according to the measurement lofting result.

The spraying temperature of the asphalt is 185-190 ℃, the spraying amount is 2.0-2.5 kg/m2, the spraying lap width is 5-7 cm, the crushed stone is uniformly dispersed, the particles are not overlapped and piled, and the stone coverage rate is 60-70%.

6. Under floor construction

The construction process is not different from the conventional operation method, and is not described in detail.

7. Laying geogrid

After the quality of the lower layer is qualified, the width of the geogrid is 1.4m (within 70cm of each of two sides of the groove) laid at the position right above the groove. Glass fiber geogrids can be adopted, nails cannot be nailed on the glass fibers when the geogrids are fixed by nails, and the glass fibers cannot be directly knocked by a hammer. The geogrid is in a straight and tensioned state in the longitudinal direction and the transverse direction.

8. Construction of upper surface layer

The construction process is not different from the conventional operation method, and is not described in detail.

Compared with the existing method for directly repairing the crack of the water stable layer, the construction method of the invention shortens the construction period, saves part of labor cost and mechanical retention cost, and greatly reduces the irregular crack of the water stable layer. Meanwhile, the asphalt pavement above the groove is not provided with reflection cracks, the effect is better, and the method has great popularization value.

Because the construction method of the invention is to carry out groove processing immediately after the water stabilization layer is rolled, compared with the prior art in which row-division repairing is carried out after the curing period is finished, the construction period is shortened by nearly 10 days.

By adopting the construction method, the water stable layer after the end of the age has no large-scale cracks and transverse and longitudinal cracks, and achieves good expected effect. In addition, the asphalt upper surface layer right above the groove has no reflection cracks and the like, and the whole effect is ideal.

And the construction method of the invention obtains better economic benefit.

The specific economic benefits created by the construction method of the invention compared with the conventional direct crack repair method are shown in Table 1, taking the repair cost of a water-stable crack of 2000m as a calculation standard:

TABLE 1 fee comparison Table

Serial number	Item	Unit of	Unit price of	Consumption of	Expense (Yuan)
						1	Labor cost	Working day	4000/4000	4/8	16000/32000
2	Cost of materials	--	--	--	--
						2.1	Iron sheet	Block	10/0	360/0	3600/0
2.2	Geotextile	m2	4/0	504/0	2016/0
						2.3	Geogrid	m2	8/0	360/0	2880/0
2.4	SBS modified asphalt	Ton of	3200/3200	0.18/0.40	576/1280
						3	Machinery fee	Desk and chair	1000/1000	2/3	2000/3000
4	Sum of charges	--	--	--	27072/36280

Note: in the table of "-/-" slash, the left data is the cost generated by the construction method of the present invention, and the right data is the cost generated by the direct crack repairing method

As can be seen from Table 1, the construction method of the present invention saves, during the 2000m water-stable layer crack treatment: 36280 and 27072 are 9208 yuan.

The embodiments of the present invention are described above with reference to the drawings, and the embodiments and features of the embodiments of the present invention may be combined with each other without conflict. The present invention is not limited to the above-described embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many modifications without departing from the spirit and scope of the invention as defined in the appended claims.