CN116607371A

CN116607371A - Base layer and lower surface layer paving compaction method for highway asphalt pavement construction

Info

Publication number: CN116607371A
Application number: CN202310635218.3A
Authority: CN
Inventors: 贾飞; 杜金钊; 韩晓冲; 谭德用; 徐长春; 岳凌锋; 赵翔; 秦运强; 马进学; 赵朋欣
Original assignee: Road and Bridge International Co Ltd; China Communications Road and Bridge North China Engineering Co Ltd; CCCC Investment Co Ltd; CCCC Jijiao Expressway Investment and Development Co Ltd
Current assignee: Road and Bridge International Co Ltd; China Communications Road and Bridge North China Engineering Co Ltd; CCCC Investment Co Ltd; CCCC Jijiao Expressway Investment and Development Co Ltd
Priority date: 2023-05-31
Filing date: 2023-05-31
Publication date: 2023-08-18

Abstract

The invention discloses a paving compaction method for a base layer and a lower layer of a highway asphalt pavement, which comprises the following steps: preparing construction according to a lower bearing layer site of a base layer to be paved; performing construction lofting aiming at a lower bearing layer with construction preparation completed; respectively erecting templates according to the layered spreading of the base layer and the large-thickness spreading of the base layer; preparing a mixture, transporting the mixture and discharging the mixture to a paver; paving and rolling the mixture based on a paver; and (5) performing joint and health care treatment after finishing rolling operation. The technical problems that construction details of a road surface structural layer are not well processed, the road surface structure is easy to collapse after long-term loading in use, and uneven road surface is caused in the prior art are solved.

Description

Base layer and lower surface layer paving compaction method for highway asphalt pavement construction

Technical Field

The invention relates to the technical field of highway engineering construction, in particular to a base layer and an underlying layer paving compaction method for highway asphalt pavement construction.

Background

At present, the road asphalt pavement is usually paved by taking stone and sand as aggregate, mineral powder as filler, and asphalt as cementing material, and heating, pouring or mixing. Asphalt pavement layers generally include a face layer, a base layer, and an underlayment, wherein the base layer is a layer disposed below the face layer for primary load bearing, and the underlayment is a layer disposed below the base layer for secondary load bearing, all of which are synchronized with the face layer to bear the vehicle load.

In the prior art, in order to ensure that the urban vehicles run stably, the road surface is required to be kept flat, and the uneven road surface is extremely easy to cause the vehicles to jolt, so that the safe and stable running of the vehicles is limited. The current construction pavement can be flattened during construction, but due to poor construction detail treatment, the defects of easy occurrence of pavement structure damage, sinking and the like after long-term use under the load of a vehicle are caused, and uneven pavement is caused, accumulated water is generated for jolting, and traffic safety of the vehicle is seriously influenced.

Disclosure of Invention

Therefore, the invention provides a base layer and an underlying layer paving compaction method for highway asphalt pavement construction, which are used for solving the technical problems that the pavement structure is easy to be damaged after long-term loading in use and uneven pavement is caused due to poor construction detail treatment of pavement construction layers in the prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

the basic layer paving compaction method for highway asphalt pavement construction comprises the following steps:

preparing construction according to a lower bearing layer site of a base layer to be paved;

performing construction lofting aiming at a lower bearing layer with construction preparation completed;

Respectively erecting templates according to the layered spreading of the base layer and the large-thickness spreading of the base layer;

preparing a mixture, transporting the mixture and discharging the mixture to a paver;

paving and rolling the mixture based on a paver;

and (5) performing joint and health care treatment after finishing rolling operation.

On the basis of the technical scheme, the invention is further described as follows:

as a further scheme of the invention, the construction preparation is carried out according to the lower bearing layer field of the base layer to be paved, and the construction preparation method specifically comprises the following steps:

before the subbase layer is paved, removing floating soil, sundries and accumulated water on the surface of the lower supporting layer, sprinkling water on the surface of the lower supporting layer for wetting, and carrying out re-pressing and leveling; for loosening and spring phenomena of corresponding roadbed of the lower bearing layer, the water-stabilized graded broken stone mixture is blended for filling treatment through excavation and airing;

when the base layer is paved and rolled in a layered manner, the base layer is supported by channel steel with the height of 18cm and the length of 3 m; when the base layer is paved and pressed correspondingly to the large thickness of the base layer, the base layer is supported by a thickened steel mould with the height of channel steel being 20cm+14cm, and a transverse support is additionally arranged every 1.5m, so that the support is firm and reliable.

As a further scheme of the invention, the construction lofting is carried out for the lower bearing layer with the construction ready to be completed, and specifically comprises the following steps:

Recovering a central line through a total station, lofting every 10m corresponding to the straight line segment, lofting every 5m corresponding to the curve segment, and simultaneously, lofting side piles at two sides of the line segment;

according to the positions of the central line and the side piles, a reference steel wire supporting steel bar is firmly supported every 10m, and the supporting steel bar is consistent with the central line pile number of the central line; meanwhile, according to the control elevation at two sides of the subbase layer, a standard steel wire rope is erected by means of control measurement through a level gauge, binding is firm between the standard steel wire rope and a cross rod of a supporting steel drill rod through binding bands, tensioning treatment is carried out on two ends of the standard steel wire rope through a pair of wire tighteners, the erection length of each section of standard steel wire rope is controlled according to 100m, and the sensor receiving tension of the standard steel wire rope is ensured to reach 1000N;

more specifically, the elevation control expression of the reference wire rope is:

H＝H1+L×i+H2+ΔH+D

wherein H is the standard steel wire elevation; h1 is the design elevation of the pavement structural layer; l is the distance between the reference steel wire and the designed elevation position; i is a road surface transverse slope; h2 is the reserved working height (typically 10 cm); ΔH is the difference between the loose thickness and the design thickness; d is the reference wire rope diameter (3.5 mm).

As a further scheme of the invention, the method for respectively erecting templates according to layered paving of a base layer and large-thickness paving of the base layer specifically comprises the following steps:

The template installation procedure of the layered paving and rolling construction of the base layer is as follows:

the subbase layer construction, in order to guarantee the edge compactness, one side close to the road shoulder adopts the soil road shoulder as a side die, the middle separation belt position adopts channel steel as a template, and the template formed by the channel steel adopts steel drill rod support firmly;

for construction of a soil shoulder, a mould is supported at one side close to a roadbed, soil is filled and leveled by manual cooperation with machinery, and small-sized vibration tamping is adopted, so that the compactness is not less than 90%; spraying cement paste on the edge after removing the die, arranging an opening at the rapid trough, and adopting mortar to smear for scour prevention;

installing channel steel templates, wherein the middle separation belt position templates adopt channel steel with the height of 18cm, the length of each channel steel is 3m, and inclined supports are added at the two ends and the middle of the channel steel to form the channel steel templates and are firmly fixed by fixed steel drills;

the template installation procedure during the process of spreading and pressing the base layer with large thickness is as follows:

constructing a subbase layer, adopting a soil shoulder as a side mould at one side close to the shoulder, adopting 34cm high channel steel at the middle separation belt position, forming channel steel templates by 3m of each channel steel length, and fixing steel drills firmly;

the construction of the soil road shoulder, the soil road shoulders on two sides are compacted according to the design width of the base layer, the compacted height of the road shoulder is as thick as the design base layer, the road shoulder adopts a soil road shoulder film sliding machine to form at one time to reach the specified compactness, the compacted road shoulder is isolated from the water-stable graded broken stone mixture by adopting a plastic film, the mixture is not polluted, and the phenomenon that the water at the edge of the water-stable graded broken stone mixture is loosened after being absorbed by road shoulder soil is overcome.

As a further aspect of the present invention, the preparing a mixture, transporting the mixture and discharging to a paver, specifically includes:

the method comprises the steps of mixing the mixture, intensively mixing the mixture by using a vibrating mixer, and adjusting the water content according to weather conditions, air temperature and front field paving reflection conditions in the mixing production process;

after starting mixing, sampling the mixed mixture to check whether the mixed mixture accords with the mixing ratio, and if the deviation exceeds the limit, analyzing the reason and adjusting in time; after formal production, checking whether the mixing proportion, cement dosage and water content are changed at regular time; during high-temperature operation, the water content in the morning and evening and the water content in the noon are correspondingly adjusted according to the temperature change;

for the transportation of the mixture, the mixer is provided with a feed bin with a valve hopper; uniformly charging materials at a discharge hole of the mixer according to the shape of a front, a rear and a middle Chinese character 'pin', so as to reduce segregation;

for discharging the mixture, 1/3 of the mixture in the hopper of the paver is ensured to be discharged when the next vehicle is started, the number of times of receiving the hopper is reduced, and the mixture is prevented from being discharged until the paver finishes paving all the mixture in the hopper;

in order to prevent the segregation of the mixture, the carriage is slowly lifted when the transport vehicle discharges, so that the mixture is prevented from rolling into the paver in a large area due to one-time grooving to the top.

As a further scheme of the invention, the paver-based operation for paving and rolling the mixture specifically comprises the following steps:

before paving, checking the flatness of the screed plate, and sprinkling water to wet the surface of the lower bearing layer;

the conventional water-stable base layer and base layer mixture is directly paved in three layers by two pavers, and the paving compaction thickness is 18cm+18cm+18cm in sequence;

the large-thickness water-stable mixture adopts two pavers with an automatic leveling function, two layers of lower base layers and lower base layers of a base layer are paved on the basis of one layer of water-stable base layer, the two layers of lower base layers and lower base layers are paved at the same time, and the two layers of lower base layers and lower base layers are rolled and formed at the same time, and the compaction thickness is 34cm+20cm;

the front-back interval of the two pavers is not more than 10m, and the middle screed plate is lapped for 30-50 cm.

The loosening coefficient is determined and controlled according to a laboratory test, the paving starting speed of the paver is 1m/min, and the ramming frequency of a rammer of the paver is 50Hz; the normal paving speed is 1.5m/min, and the ramming frequency of the rammer of the paver is 60Hz; the rammer frequencies of the two pavers are kept consistent, so that the initial compactness reaches 80%, and the two side edges are tracked and processed after the pavers, so that edge segregation is avoided;

providing tracking treatment of coarse and fine aggregate segregation, removing local coarse aggregate pits, and filling with new mixture; the paving operation is continuously carried out, and if the paving operation is interrupted for more than 2 hours due to reasons, a transverse joint is supported;

The specific paving operation method comprises the following steps:

(1) When the paver starts, the frequency of the rammer is regulated to be in a certain proportional relation with the paving speed;

(2) When the double-machine paving is performed, the front-stage paver adopts a road side standard steel wire rope and guide beams arranged in the road to control the elevation, the guide beams hang on lines according to the standard steel wire ropes at the two sides as standard surfaces to adjust the elevation, and the road side of the rear-stage paver adopts the standard steel wire rope and a skid shoe to control the elevation;

(3) The travelling speed of the paver is controlled to be 1.5m/min, the speed of the paver is adapted to the mixing capacity, the paver keeps advancing at a uniform speed to the greatest extent, and paving is not stopped or interrupted;

(4) 2/3 of the spiral distributor of the paver is buried in the mixture during paving to reduce segregation;

(5) Local segregation phenomenon tracking cancellation: removing the 'pit' of the local coarse aggregate, and filling with the newly mixed mixture; the serious part is replaced and filled according to the 'square supplement principle';

(6) The part which cannot be paved by the machine is paved by a manual method, and the elevation is controlled by a hanging wire method during manual paving;

(7) And (3) tracking and detecting the loose pavement thickness after paving, and immediately taking remedial measures when abnormality occurs.

(8) The front of the paver is additionally provided with a rubber baffle, and the distance between the bottom of the baffle and the lower bearing layer is not more than 10cm.

The rolling operation method for the mixture is as follows:

(1) After the mixture is paved and formed, rolling from low to high in the full-width range; when rolling, the rolling principle of static pressure before vibration, low speed and low line from low to high and high frequency and low amplitude is followed, and the rolling is carried out until no wheel track exists; ensuring that the vibration pressure does not wave and move; the road roller is overlapped by 1/2 wheel width during rolling, the rolling speed is controlled to be 1.6km/h for the 1 st to 2 nd times, and then the rolling speed is controlled to be 2.0km/h for each time; please refer to table 1-table 2 for specific construction schemes:

table 1 basic layer layered paving and rolling process mechanical combination rolling construction scheme

Table 2 basic layer large thickness paving and rolling process mechanical combination rolling construction scheme

(2) The surface layer of the lower bearing layer is always in a wet state in the rolling process;

(3) The joint is staggered into a step shape of 45 degrees transversely when being longitudinally rolled (the minimum staggering is 1 m), and the joint is rolled by 45 degrees outwards after being rolled;

(4) In the rolling process, eliminating and remedying the phenomena of loosening and peeling of the spring, and ensuring that the compacted surface is flat and compact without wheel marks or bulges and generating a phenomenon of big waves;

(5) For the corner sections of the access boards, a large-sized road roller is combined with a small-sized road roller to carry out transverse reinforced rolling, and the positions which cannot be rolled are encrypted and tamped by using a vibrating ram with higher power;

(6) Staggered when the road roller is temporarily stopped, the interval is not less than 3m, and the road roller is suspended on the road section which is rolled completely;

(7) After the rolling operation section is finished, the compactness is rapidly detected, and the compaction is insufficient to be carried out as soon as possible;

(8) In order to ensure the compactness and strength of the edge, the edge is pressurized at least one time more than the normal section position, cement slurry is manually sprayed on the edge of the template before rolling, and a small rammer is adopted to perform ramming after the re-compaction is finished.

As a further scheme of the invention, the joint and health care treatment is carried out after the rolling operation is completed, and specifically comprises the following steps:

the transverse seam is arranged at the position of the bridge head butt strap after construction is finished, so that the transverse working seam is reduced;

when a transverse working seam is arranged outside the bridge head, the two pavers distribute the mixture of the last vehicle, the paving positions of the two pavers are level when the plate is lifted, the flatness of the joint is measured by a 3m ruler after rolling, and the part with unqualified flatness and thickness is completely removed, so that the transverse working seam is perpendicular to the direction of the route;

the rolling method at the joint is as follows:

the rolling of the transverse joint is firstly carried out by using a double-steel-wheel road roller, the road roller is positioned on the compacted mixture surface during rolling, the width of the road roller extending into the new pavement is 15cm, and then the road roller moves 15-20 cm towards the newly paved mixture every time of rolling until the road roller is completely positioned on the new pavement, and then longitudinal rolling is carried out; the part which cannot be rolled by the bridge head road roller during construction is tamped manually by adopting vibration tamping;

Immediately after construction, a piece of cloth and a piece of membrane geotextile are adopted for covering and preserving, the geotextile is tightly covered, the geotextile is covered and overlapped according to the transverse slope and the longitudinal slope directions, the low-position high position is provided with 15-20 cm of overlapping width, the water filling is convenient for preserving, the preserving effect is achieved, the geotextile is wrapped and pressed by a sand bag, proper water supplementing is carried out after the cement is finally solidified, and the concrete water supplementing method comprises the following steps: the water flows from high to low until the water is soaked in a large area;

after the curing is up to 7 days, indexes such as integrity, framework distribution uniformity, thickness, strength, elevation, transverse slope, width, flatness and the like are detected by coring according to the frequency required by the specification, and the next working procedure construction is carried out after each index meets the design and specification requirements.

The lower layer paving compaction method for highway asphalt pavement construction is continuously executed based on the basic layer paving compaction method, and specifically comprises the following steps of:

performing construction cleaning on a lower bearing base layer site to be paved with a lower surface layer, and sprinkling penetrating layer oil;

the real-time temperature of the asphalt mixture paved in each stage is mastered and controlled, and the asphalt mixture is transported to a paver for paving and rolling the mixture.

As a further scheme of the invention, the construction cleaning is carried out on the lower bearing base layer site of the lower surface layer to be paved, and the penetrating layer oil is sprayed, which specifically comprises the following steps:

The cleaning method for the lower bearing base layer comprises the following steps:

before construction, trimming the surface of the lower bearing base layer, removing loose particles, filling coring holes, sweeping the surface, strengthening and sweeping the disease treated part, and brushing by adopting a steel brush when clay blocks exist;

the method for spreading penetrating layer oil comprises the following steps:

after the surface is dried, spraying penetrating oil, spreading the penetrating oil by adopting an asphalt spreader, wherein the spreading amount is 1.1L/square meter, the spreading speed is 15km/h, and the spraying amount is stable; the sprayed transparent layer oil whisker is uniformly atomized and uniformly distributed into a thin layer in the whole width of the pavement, so that the phenomenon that the sprayed oil whisker is in a shape of a strip or a spray is avoided, and the sprayed oil whisker is prevented from accumulating; spreading penetrating oil and crushing stone synchronously, wherein the amount of the crushed stone for construction is 12kg per square meter, and the amount of asphalt spread is 1.15kg per square meter.

As a further scheme of the invention, the method for controlling the real-time temperature of the asphalt mixture during each stage of paving comprises the following steps of:

the wire point control network and the elevation control network have completed encryption construction, and after the penetrating layer construction is completed, the following steps of elevation detection recording, temperature control and paving preparation are carried out before the paving construction of the lower layer:

(1) Strictly grasping heating temperature of asphalt and aggregate and delivery temperature of asphalt mixture;

(2) The temperature control is used as key control of asphalt paving, and is arranged in front and back fields to be checked and recorded in a vehicle-by-vehicle and procedure-by-procedure mode during construction, so that summary data are formed for construction;

(3) The mixing time of each tray of material is controlled to be 60s, and the dry mixing time is controlled to be 5s; after a specified amount of aggregate and asphalt are fed into a stirring pot, the two materials are fully mixed until all aggregate particles are completely and uniformly covered by asphalt, the asphalt materials are also completely and uniformly distributed into the whole mixture, and the mixture is white-free and asphalt clusters-free;

(4) After at least five skip cars with proper temperatures in front of the paver wait, starting to pave the mixture;

the process of transporting the mixture is as follows:

(1) In order to prevent asphalt mixture from sticking to a vehicle and facilitate unloading, an anti-sticking agent is coated in a carriage before the asphalt mixture is loaded into the vehicle; temperature detection and recording are carried out before each vehicle material goes out of the field, after the vehicle material is paved and rolled;

(2) In order to reduce segregation, the mixture is loaded in the order of front, back and middle, so that the mixture is prevented from being loaded into a cone at one time;

(3) After the loading is completed, tarpaulin is covered in time to prevent the temperature segregation of the mixture;

(4) When the transport vehicle enters a construction site, the tires are clean and pollution-free; paving wet cotton quilts before entering a construction site to prevent pollution;

The mixture paving and shaping operation is as follows:

(1) Before paving the lower layer of asphalt, cleaning the surface pollution and sundries of the sealing layer;

(2) Paving the surface asphalt mixture by adopting 2 Fowler 2100 pavers to perform paving molding; the two pavers are in echelon paving, the front-back interval is 10-15 m, and the screed plates are lapped for 10-15 cm;

(3) The flat plate is preheated and scalded 1 hour in advance before the operation and construction of the paver, and the temperature is not lower than 110 ℃;

(4) The paver needs to slowly, uniformly and continuously pave without interruption, the paving speed is controlled to be 2m/min, and random speed change or midway pause is avoided;

(5) The paver adopts an automatic leveling mode, and adopts a steel wire rope to guide and control the thickness and the elevation; control piles are arranged on two sides of the paver every 10 meters (proper encryption is suitable for the super-high road section); in the paving process, steel drill rod detection thickness and leveling instrument measurement elevation double control are adopted, so that the paving thickness is ensured;

the rolling operation of the mixture is as follows:

(1) Initial pressure: the static pressure of the 1 double-steel-wheel road roller is followed by the paver, the static pressure is followed by 1 time of weak vibration, and the rolling speed is 2-2.5km/h;

(2) And (3) re-pressing: immediately following the initial compaction, 3 double-steel-wheel road rollers are high-frequency and low-amplitude for 3 times, 2 rubber-wheel road rollers immediately following the double-steel-wheel road rollers are kneaded for not less than 3 times, and the rolling speed is 3-4km/h;

(3) Final pressure: immediately pressing again, and using 1 double-steel-wheel road roller to static pressure for 1-2 times until no track exists, wherein the rolling speed is 3-6km/h;

asphalt mixture compaction follows the rolling principle of follow immediately, little water, slow pressure, high frequency and low amplitude;

as an alternative implementation method of the working procedure of the mixture rolling:

(1) Initial pressure: the initial pressure temperature is not less than 140 ℃ in normal construction;

(2) And (3) re-pressing: the double-pressed section is prevented from overlapping with the section with unfinished initial pressure, and a distance of about 10m is kept between the double-pressed section and the initial-pressed section;

before the rubber-wheel road roller enters the pavement paving and is re-pressed, a spacer is smeared to avoid sprinkling, and the rubber-wheel road roller enters the next re-pressing section after the temperature of the tire is increased as much as possible on the first re-pressing section; the length of the first double-pressure paragraph is about 30-50 m, and the times of smearing the isolating agent are reduced when the temperature of the rubber wheel is increased and no obvious wheel sticking phenomenon exists in the double-pressure process; the adjacent rolling belts of the rubber wheels are overlapped or the width of the rolling wheels is 1/2-1/3, and the overlapping track belts of the double-steel-wheel road roller are 20 cm-30 cm;

(3) Final pressure: the final pressing is carried out immediately after the back pressing, 1 double-steel-wheel vibratory roller is adopted to carry out static pressure smooth surface, eliminate wheel track and grind for 2 times; the speed is controlled to be 3-6km/h; the final pressure temperature is greater than 90 ℃;

(4) The specific rolling method comprises the following steps: rolling from outside to inside and from low to high; the road roller avoids staying on the pressed mixture with the temperature higher than 60 ℃;

(5) Wheel sticking prevention measures: in order to prevent the phenomenon of sticking to the wheel in the rolling process of the road roller, spraying mist water on the rolling wheel of the steel-wheel road roller, coating vegetable oil on the rubber-wheel road roller or refitting an automatic coating device to coat oil, wherein the coating amount keeps preventing the vegetable oil from being scattered to the lower layer of asphalt to influence the direct bonding effect of each layer, and the anti-sticking wheel measures of the road roller prevent the diesel oil from being coated strictly;

(6) And (3) transverse seam treatment:

the transverse joints are all flat joints, and the transverse joints among all layers are staggered by at least 3 m;

when the construction is finished, the paver slightly lifts the screed plate away from the site at the position close to the end part 1m, after finishing rolling, asphalt is cooled to below 50 ℃, flatness is detected by a 6m ruler, a part with flatness exceeding 3mm is marked by an ash line, a cutting machine is adopted to cut along the ash line, then the part is shoveled, and the inner side surface layer of the ash line is prevented from being disturbed in the shoveling process; before the next construction, brushing hot asphalt at the transverse seam, and preheating and paving the end part of the reserved transverse seam by using a screed plate of a paver; seam rolling is carried out through a road roller, transverse rolling is carried out from the formed surface layer to the newly paved surface layer, 5-10 cm is cut into each time, transition is gradually carried out until the steel wheel rolling of the road roller completely enters the newly paved surface, and then longitudinal rolling is carried out.

The invention has the following beneficial effects:

1. the method can effectively prolong the service life of the pavement structure and ensure the driving safety of vehicles on the basis of improving construction procedures and details.

2. The method has the advantages that two layers of the base layer and the subbase layer with large thickness are paved at the same time:

the construction period is shortened. When the layering construction is carried out, a longer life time is needed after the lower layer construction is finished, at least 7 days are needed for paving the upper layer, and the construction period is prolonged. And the large-thickness paving saves construction preparation time such as material preparation, formwork supporting, cleaning, cement slurry spraying and the like besides saving a 7-day life.

Early damage of the base (subbase) layer is avoided. Even after the life-preserving period of the lower base layer is finished, the strength of the lower base layer is not fully formed in the paving process of the upper base layer, and early damage of the lower base layer structure is easily caused by rolling of a large-tonnage vibrating roller and an engineering transport vehicle in the construction of the upper base layer, so that the lower structure is insufficient in spallation, microscopic crack development and strength formation, and the paving with large thickness is carried out at one time, so that early damage of the base layer is completely avoided.

The segregation generated in the design of the traditional paver is reduced. The large-thickness super paver is specially designed for resisting segregation in the transverse direction, the longitudinal direction and the height direction, and segregation generated during construction of the traditional paver is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will simply refer to the drawings required in the embodiments or the description of the prior art, and structures, proportions, sizes and the like which are shown in the specification are merely used in conjunction with the disclosure of the present invention, so that those skilled in the art can understand and read the disclosure, and any structural modifications, changes in proportion or adjustment of sizes should still fall within the scope of the disclosure of the present invention without affecting the effects and the achieved objects of the present invention.

Fig. 1 is a schematic diagram of a pavement base layer construction process flow of a base layer paving compaction method for highway asphalt pavement construction according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a pavement subsurface layer construction process flow of a pavement subsurface layer paving compaction method for highway asphalt pavement construction according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a rolling state of a mixture in a paving compaction method of a base layer and an underlying layer for highway asphalt pavement construction according to an embodiment of the present invention.

Detailed Description

Other advantages and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, by way of illustration, is to be read in connection with certain specific embodiments, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The terms such as "upper", "lower", "left", "right", "middle" and the like are also used herein for descriptive purposes only and are not intended to limit the scope of the invention for which the invention may be practiced or for which the relative relationship may be altered or modified without materially altering the technical context.

As shown in fig. 1 to 3, the embodiment of the invention provides a paving compaction method for a base layer and a lower layer of a highway asphalt pavement construction, which is used for effectively prolonging the service life of a pavement structure and ensuring the driving safety of vehicles on the basis of improving construction procedures and details. The embodiment of the invention provides a base layer paving compaction method for highway asphalt pavement construction, which comprises the following steps:

s1: preparing construction according to a lower bearing layer site of a base layer to be paved;

the method comprises the following steps: before the subbase layer is paved, removing floating soil, sundries and accumulated water on the surface of the lower supporting layer, sprinkling water on the surface of the lower supporting layer for wetting, and carrying out re-pressing and leveling; and (3) for loosening and spring phenomena of corresponding roadbed of the lower bearing layer, performing filling treatment by excavating and airing, and blending water-stabilized graded broken stone mixture.

S2: performing construction lofting aiming at a lower bearing layer with construction preparation completed;

the method comprises the following steps: and recovering the central line through the total station, lofting every 10m corresponding to the straight line segment, lofting every 5m corresponding to the curve segment, and simultaneously, lofting the side piles at two sides of the line segment.

According to the positions of the central line and the side piles, a reference steel wire supporting steel bar is firmly supported every 10m, and the supporting steel bar is consistent with the central line pile number of the central line; meanwhile, according to the control elevation of the two sides of the subbase layer, a standard steel wire rope is erected by means of control measurement through a level gauge, binding belts are adopted between the standard steel wire rope and a cross rod of a supporting steel drill rod firmly, two ends of the standard steel wire rope are tensioned through wire tighteners, the erection length of each section of standard steel wire rope is controlled according to 100m, and the sensor receiving tension of the standard steel wire rope is ensured to reach 1000N.

H＝H1+L×i+H2+ΔH+D

S3: respectively erecting templates according to the layered spreading of the base layer and the large-thickness spreading of the base layer;

The method comprises the following steps: the template for layered paving and rolling construction of the base layer is installed as follows:

the template is installed during the process of spreading and pressing the base layer with large thickness as follows:

S4: preparing a mixture, transporting the mixture and discharging the mixture to a paver;

the method comprises the following steps: the water content of the mixture is adjusted according to weather conditions, air temperature and front field paving conditions in the mixing production process.

After starting mixing, sampling the mixed mixture to check whether the mixed mixture accords with the mixing ratio, and if the deviation exceeds the limit, analyzing the reason and adjusting in time; after formal production, checking whether the mixing proportion, cement dosage and water content are changed at regular time; during high-temperature operation, the water content in the morning and evening and the water content in the noon are correspondingly adjusted according to the temperature change.

For the transportation of the mixture, the mixer is provided with a feed bin with a valve hopper; the materials are uniformly filled at the discharge port of the mixer in the shape of a Chinese character 'pin', and segregation is reduced.

For discharging the mixture, the discharging operation of the next vehicle is performed after 1/3 of the mixture in the hopper of the paver is ensured, the number of times of receiving the hopper is reduced, and the discharging operation is avoided until the paver finishes paving all the mixtures in the hopper.

S5: paving and rolling the mixture based on a paver;

the method comprises the following steps: and (3) checking the flatness of the screed plate before paving, and sprinkling water to wet the surface of the lower bearing layer.

The conventional water-stable base layer and base layer mixture is directly paved in three layers by adopting two ABG8820 pavers, and the paving compaction thickness is 18cm+18cm+18cm in sequence.

The large-thickness water-stable mixture adopts two pavers and has an automatic leveling function, on the basis of a water-stable base layer, the base layer and the lower base layer are paved in two layers, the lower base layer and the lower base layer are paved simultaneously and rolled simultaneously, the compaction thickness is 34cm+20cm, the cement stabilized macadam mixing ratio of the base layer is adopted for construction, the bearing bonding surface is reduced, the overall stability of the base layer is improved, the curing time is saved, and the construction efficiency is improved to a certain extent. The front-back interval of the two pavers is not more than 10m, and the middle screed plate is lapped for 30-50 cm.

The loosening coefficient is determined and controlled according to a laboratory test, the paving starting speed of the paver is 1m/min, and the ramming frequency of a rammer of the paver is 50Hz; the normal paving speed is 1.5m/min, and the ramming frequency of the rammer of the paver is 60Hz; the rammer frequencies of the two pavers are kept consistent, so that the initial compactness reaches 80%, and the two side edges are tracked and processed after the pavers, so that edge segregation is avoided.

Providing tracking treatment of coarse and fine aggregate segregation, removing local coarse aggregate pits, and filling with new mixture; the paving operation is continuously carried out, and if the paving operation is interrupted for more than 2 hours for reasons, transverse joints are supported.

The concrete paving method comprises the following steps:

The rolling method for the mixture comprises the following steps:

(3) Referring to FIG. 3, the joint is staggered into a step shape of 45 degrees transversely when being longitudinally rolled (minimum staggered by 1 m), and is rolled by 45 degrees outwards after being rolled;

S6: after finishing rolling operation, performing joint and health care treatment;

the method comprises the following steps: and after construction, the transverse seam is arranged at the position of the bridge head butt strap, so that the transverse working seam is reduced.

When the transverse working seam is arranged outside the bridge head, the two pavers distribute the mixture of the last vehicle, the paving positions of the two pavers are flush when the plate is lifted, the flatness of the joint is measured by a 3m ruler after rolling, and the unqualified parts of the flatness and thickness are completely removed, so that the transverse working seam is perpendicular to the direction of the route.

Rolling mode at joint:

the rolling of the transverse joint is firstly carried out by using a double-steel-wheel road roller, the road roller is positioned on the compacted mixture surface during rolling, the width of the road roller extending into the new pavement is 15cm, and then the road roller moves 15-20 cm towards the newly paved mixture every time of rolling until the road roller is completely positioned on the new pavement, and then longitudinal rolling is carried out; and (3) tamping the part which cannot be rolled by the bridge head road roller during construction by adopting a vibration rammer.

Immediately covering and preserving the soil by using a cloth-film geotextile after construction is finished, wherein the geotextile is tightly covered, the geotextile is overlapped according to the transverse slope and longitudinal slope directions, the overlapping width of the low-pressure part is 15-20 cm, the filling of the preserving water is convenient, the preserving effect is achieved, the geotextile is wrapped and pressed by using a sand bag, and proper water supplementing is carried out after the cement is finally solidified; the specific water supplementing method comprises the following steps: and the water flows from high to low until the water is soaked in a large area.

The embodiment of the invention also provides a paving compaction method of the lower layer for highway asphalt pavement construction, which comprises the following steps:

s1: performing construction cleaning on a lower bearing base layer site to be paved with a lower surface layer, and sprinkling penetrating layer oil;

the method comprises the following steps: the cleaning method for the lower bearing base layer comprises the following steps:

The method for spreading penetrating layer oil comprises the following steps:

S2: grasping and controlling the real-time temperature of the asphalt mixture to be paved at each stage, and transporting the asphalt mixture to a paver to perform paving and rolling operations of the mixture;

the method comprises the following steps: the wire point control network and the elevation control network have completed encryption construction, and after the penetrating layer construction is completed, the following steps of elevation detection recording, temperature control and paving preparation are carried out before the paving construction of the lower layer:

(4) And after at least five skip cars with proper temperatures in front of the paver wait, the mixture paving is started.

The process of transporting the mixture is as follows:

(4) When the transport vehicle enters a construction site, the tires are clean and pollution-free; and a wet cotton quilt is paved before entering a construction site, so that pollution is prevented.

The mixture paving and shaping operation is as follows:

(5) The paver adopts an automatic leveling mode, and adopts a steel wire rope to guide and control the thickness and the elevation; control piles are arranged on two sides of the paver every 10 meters (proper encryption is suitable for the super-high road section); and in the paving process, steel drill detection thickness and leveling instrument measurement elevation double control are adopted, so that the paving thickness is ensured.

The rolling operation of the mixture is as follows:

(3) Final pressure: and (3) immediately carrying out back-pressing, and carrying out static pressure on 1 double-steel-wheel road roller for 1-2 times until no track exists, wherein the rolling speed is 3-6km/h.

(3) Final pressure: the final pressing is carried out immediately after the back pressing, 1 double-steel-wheel vibratory roller is adopted to carry out static pressure smooth surface, eliminate wheel track and grind for 2 times; the speed is controlled to be 3-6km/h; the final pressure temperature is greater than 90 ℃.

(5) Wheel sticking prevention measure

In order to prevent the phenomenon of sticking the roller in the rolling process of the roller, vaporific water is sprayed on the rolling wheel of the steel-wheel roller, the vegetable oil is smeared on the rubber-wheel roller or an automatic smearing device is refitted to smear the oil, the smearing amount is kept to prevent the vegetable oil from being scattered to the lower layer of asphalt, the direct bonding effect of each layer is affected, and the anti-sticking wheel measures of the roller strictly prevent diesel oil from being smeared.

(6) Transverse seam treatment

While the invention has been described in detail in the foregoing general description and specific examples, it will be apparent to those skilled in the art that modifications and improvements can be made thereto. Accordingly, such modifications or improvements may be made without departing from the spirit of the invention and are intended to be within the scope of the invention as claimed.

Claims

1. The base layer paving compaction method for highway asphalt pavement construction is characterized by comprising the following steps of:

paving and rolling the mixture based on a paver;

2. The method for compacting a base course for road asphalt pavement construction according to claim 1, wherein,

the construction preparation is carried out according to the lower bearing layer site of the base layer to be paved, and the construction preparation method specifically comprises the following steps:

3. The method for compacting a base course for road asphalt pavement construction according to claim 2, wherein,

the construction lofting is carried out on the lower bearing layer of which the construction preparation is finished, and specifically comprises the following steps:

H＝H1+L×i+H2+ΔH+D

4. The method for compacting a foundation layer for road asphalt pavement construction according to claim 3, wherein,

the template is respectively erected according to the layered spreading of the base layer and the large-thickness spreading of the base layer, and specifically comprises the following steps:

5. The method for compacting a foundation layer for road asphalt pavement construction according to claim 4, wherein,

the preparation mixture, transportation mixture and unloading to paver specifically includes:

6. The method for compacting a foundation layer for road asphalt pavement construction according to claim 5, wherein,

the paver-based operation for paving and rolling the mixture specifically comprises the following steps:

the front-back interval of the two pavers is not more than 10m, and the middle screed plate is lapped for 30-50 cm;

the specific paving operation method comprises the following steps:

(7) Tracking and detecting the loose pavement thickness after paving, and immediately taking remedial measures when abnormality occurs;

(8) A rubber baffle is additionally arranged in front of the paver, and the distance between the bottom of the baffle and the lower bearing layer is not more than 10cm;

the rolling operation method for the mixture is as follows:

7. The method for compacting a foundation layer for road asphalt pavement construction according to claim 6, wherein,

the joint and health care treatment is carried out after the rolling operation is completed, and specifically comprises the following steps:

the rolling method at the joint is as follows:

8. An underlying paving compaction method for highway asphalt pavement construction, characterized in that the base paving compaction method according to any one of claims 1-7 is continued, comprising the steps of:

9. The method for compacting under-layer paving for highway asphalt pavement construction according to claim 8, wherein,

the construction cleaning is carried out on the lower base layer site to be paved, and the penetrating layer oil is sprayed, specifically comprising the following steps:

The method for spreading penetrating layer oil comprises the following steps:

10. The method for compacting under-layer paving for highway asphalt pavement construction according to claim 9, wherein,

the control and control of the real-time temperature of the asphalt mixture during each stage, and the operation of transporting the asphalt mixture to a paver for paving and rolling the mixture, specifically comprises the following steps:

the process of transporting the mixture is as follows:

the mixture paving and shaping operation is as follows:

the rolling operation of the mixture is as follows:

(6) And (3) transverse seam treatment: