CN110777596A

CN110777596A - Micro-surfacing overlay construction method suitable for pavement preventive maintenance

Info

Publication number: CN110777596A
Application number: CN201910978342.3A
Authority: CN
Inventors: 王荣强; 陈虹旭; 夏立芝; 朱四营; 刘�东; 王德龙; 马连友; 范宗斌; 王岳松; 柴东然; 邢浩; 齐永超; 李志强; 刘飞; 付玉恒
Original assignee: Beijing Urban Construction Road & Bridge Group Co Ltd; Bright Transport Development Of City Of Beijing Jian Hua Co Ltd
Current assignee: Beijing Urban Construction Road & Bridge Group Co Ltd; Bright Transport Development Of City Of Beijing Jian Hua Co Ltd
Priority date: 2019-10-15
Filing date: 2019-10-15
Publication date: 2020-02-11

Abstract

The invention discloses a micro-surfacing overlay construction method suitable for pavement preventive maintenance, which comprises the following steps: step one, preparation before construction: the method comprises the steps of raw material preparation and mechanical preparation; the raw materials comprise coarse aggregates, fine aggregates, modified emulsified asphalt, fillers and additives; step two, treating the diseases of the original road surface: the method comprises the following steps of surveying an original road surface in advance, carrying out crack pouring or patching treatment on longitudinal and transverse cracks of an old road surface according to the properties of the cracks and the width of the cracks, carrying out patching treatment on parts with the ruts larger than 1.5cm or with problems of cracking, slushing and the like in advance, and carrying out fine milling and planing treatment on marked lines, arrows, speed limit and the like of the original road surface; and step three, paving. The construction technology of the micro-surfacing applied in the prior art is deeply researched and improved, and the problems of uneven appearance, smooth road, uneven joint, surface scratch and oil bleeding after the original micro-surfacing construction technology is paved, unstable quality after social vehicles pass for one month and the like are solved.

Description

Micro-surfacing overlay construction method suitable for pavement preventive maintenance

Technical Field

The invention relates to the technical field of pavement restoration, in particular to a micro-surfacing overlay construction method suitable for pavement preventive maintenance.

Background

The micro-surfacing construction technology is a preventive maintenance method developed on the basis of slurry seal. Original slurry seal was invented by german in 1920, slurry seal equipment was officially appeared in the united states in 1950, and the national department of transportation began to invest in and develop slurry seal equipment in 1986, and the original slurry seal equipment was successful.

With the improvement of materials, the 70 th german manufacturers developed slurry seals as micro-surfacing. The technology was introduced into the United states in the 80 s, and into China in the end of the 90 s. At the present stage, the technical problems of uneven appearance, smooth road, uneven joint, surface scratch, oil bleeding and unstable quality after traffic are easily caused after the micro-surfacing construction process is paved.

Disclosure of Invention

The invention aims to provide a micro-surfacing overlay construction method suitable for pavement preventive maintenance, and aims to solve the technical problems of uneven appearance, uneven joints, surface scratches, oil bleeding and unstable quality after traffic is finished after the original micro-surfacing construction process is paved.

In order to achieve the purpose, the invention adopts the following technical scheme: a micro-surfacing overlay construction method suitable for pavement preventive maintenance comprises the following steps: step one, preparation before construction: the method comprises the steps of raw material preparation and mechanical preparation;

the raw materials comprise coarse aggregates, fine aggregates, modified emulsified asphalt, fillers and additives; wherein, the addition amount of the cement is (0-2)% of the total amount of the aggregate by mass, and the specific blending proportion design scheme is determined according to the construction conditions and time. The concrete mixing ratio is stone: asphalt: water = 100: 6.0: 5.5;

step two, treating the diseases of the original road surface: the method comprises the following steps of surveying an original road surface in advance, carrying out crack pouring or patching treatment on longitudinal and transverse cracks of an old road surface according to the properties of the cracks and the width of the cracks, carrying out patching treatment on parts with the ruts larger than 1.5cm or with problems of cracking, slushing and the like in advance, and carrying out fine milling and planing treatment on marked lines, arrows, speed limit and the like of the original road surface;

step three, paving operation: according to the width of the cross section, longitudinal seams are arranged at the position which is 3-5cm near the right side of a lane line, and a sealing layer vehicle is paved at a constant speed of 20-25m per hour;

step four, lapping and treating longitudinal and transverse seams:

during paving operation, longitudinally lapping a new pavement slightly higher than a lapping surface by 1-2 mm, manually and flatly jointing the new pavement by using a shovel, enabling the longitudinal lapping surface to be open for traffic and rolled to control the seam flatness within 3mm, transversely lapping, paving a sheet of sheet iron on the lapping surface to be parallel and level with a transverse seam, starting a mixer of a seal car to start mixing slurry mixture, and when the slurry mixture is unloaded to a position above 1/2 of the height of a screw propeller of a paving box, the seal car starts to move forwards and is rapidly adjusted to a paving set thickness;

step five, processing the bridge expansion joint:

when an expansion joint of a bridge is crossed, iron sheets are adhered by an adhesive tape to protect the expansion joint with the whole paving width, so that the expansion joint is prevented from being polluted by slurry mixture, the paving thickness is reduced to 0.8cm or below after a sealing vehicle is paved to about 1m in front of the expansion joint, the paving thickness is timely adjusted to 1.2cm after the sealing vehicle drives to pass through the expansion joint for 1m, and the slurry mixture on the iron sheets is manually cleaned and the iron sheets are recycled;

and step six, opening traffic. Controlling the demulsification time of the slurry mixture within 3-4min, forming for 1 hour to have open traffic conditions, and forbidding pedestrians and vehicles to pass in the period.

Further, the method also comprises the steps of quality control, marking and delivery acceptance check in the whole construction process,

the quality control comprises the steps of detecting the oil-stone ratio and the mineral aggregate gradation of the slurry mixture every day, and performing pre-control detection on the pendulum friction coefficient, the construction depth and the water seepage coefficient of the finished pavement in time after the slurry mixture is naturally rolled for one day; and ensuring that the quality of the delivery inspection and acceptance construction meets the specification and design requirements.

Marking a marked line: according to the construction process and performance of the slurry mixture, combining a micro-surfacing and slurry seal construction technical guide, opening traffic for 1 month after construction, and marking a hot-melt marking line when the quality and performance of the slurry mixture are stable;

checking acceptance and detection of delivery: and detecting according to the technical guide of micro surfacing and slurry sealing and the design requirements of construction drawings, and meeting the specifications and the design requirements of the drawings, so that the construction of the micro surfacing is finished.

Further, the paving thickness is 0.9-2.5 cm.

Further, the modified emulsified asphalt used for the micro-surfacing overlay is BCR (standing for mixing type cationic emulsified asphalt) modified emulsified asphalt, wherein the content of emulsified asphalt residues is not less than 62%, and the softening point of the residues is at least 57 ℃.

Further, the preparation of the BCR modified emulsified asphalt needs to determine the demulsification speed of the modified emulsified asphalt according to the activity of the aggregate, the dosage and chemical components of the chemical agent, the acid value of the base asphalt and the construction air temperature condition.

Further, the mixture comprises 90-92 parts by weight of aggregate, 0-2 parts by weight of cement and 6 parts by weight of modified emulsified asphalt.

Furthermore, the aggregate specification is one or more of 0-3mm, 3-5mm and 5-8 mm.

Furthermore, a 6.3mm controllability sieve mesh is arranged in the mineral aggregate grading detection.

Furthermore, the aggregate and the mineral powder are made of basalt.

Further, in the sixth step, the demulsification time of the slurry mixture is controlled within 3-4min, the demulsification is started, the slurry mixture is formed for 10min, the condition of drawing cold paint marked lines is met within 1 hour, and traffic is opened within 1 hour to enable social vehicles to naturally roll.

The invention has the beneficial effects that:

the invention provides a micro-surfacing overlay construction method suitable for pavement preventive maintenance, which is used for deeply researching and improving the existing micro-surfacing construction technology and solving the problems of uneven appearance, smooth road, uneven joint, surface scratch, oil bleeding, unstable quality in the process of passing social vehicles for one month and the like after the original micro-surfacing construction technology is paved.

2, the micro-surfacing overlay construction method suitable for pavement preventive maintenance provided by the invention has the advantages that all selected materials are basalt, so that the effects of skid resistance, wear resistance and the like can be better achieved, and meanwhile, traffic operation can be realized, and the construction method is flexible and convenient.

The micro-surfacing technology is suitable for treating the pavement with a good base layer but obvious ruts on the surface layer of the pavement, reducing the anti-slip coefficient of the surface layer and treating the pavement with water seepage caused by fine cracks on the surface layer. The micro-surfacing technique enables very thin finishes to be made and can be used as a bridge deck finish improvement without excessive load increase. In addition, the method is also suitable for preventive maintenance of important traffic roads such as expressways, urban roads, airport runways and the like.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The primary objects and other advantages of the invention may be realized and attained by the instrumentalities particularly pointed out in the specification.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

Fig. 1 is a grading diagram.

FIG. 2 is a graph plotting 1h wet wheel wear and sand adhesion.

Detailed Description

The technical solutions of the present invention are described in detail below by examples, and the following examples are only exemplary and can be used only for explaining and illustrating the technical solutions of the present invention, but not construed as limiting the technical solutions of the present invention.

The micro-surfacing technology is characterized in that:

firstly, waterproofing: the whole pavement is paved, a waterproof layer is added, and water is prevented from seeping downwards;

secondly, wear resistance: adding a wearing layer;

thirdly, improving the anti-skid performance: friction is increased on the new road surface;

fourthly, the pavement is prevented from aging and loosening, so that the service life of the pavement is effectively prolonged;

fifthly, the stable ruts can be filled;

sixthly, traffic is opened in a shorter time;

seventh, can be used in the superficial wearing course of the new road directly, thus reduce the use of expensive stone material, reduce the project cost and reduce and basically dispel the occurrence of early water damage;

eighth, real whole environmental protection: the construction at normal temperature has no toxic smog, dust and noise pollution, and no wastewater discharge application range.

Examples

The invention provides a thin layer overlay construction method by using a slurry mixture, which starts with the research from the directions of original road surface treatment, mix proportion design, working medium application amount control and the like, wherein the paving thickness at a micro-surface is 1.0cm, the paving speed is 20-25m/min, half-width guide construction and half-width vehicle passing are implemented in the construction process.

Specifically, the method comprises the following steps:

step one, preparation before construction: the method comprises the steps of raw material preparation and mechanical preparation;

step four, lapping and treating longitudinal and transverse seams:

step five, processing the bridge expansion joint:

step six, opening traffic: controlling the demulsification time of the slurry mixture within 3-4min to begin demulsification, forming for 10min, finishing the condition of marking the cold paint line within 1 hour, and opening the traffic within 1 hour to naturally roll social vehicles. And after the construction is finished and released for one day, performing pre-control detection on the pendulum friction coefficient and the construction depth of the finished road surface in time, controlling the construction depth index to be more than 0.7 and the pendulum friction coefficient to be more than 55.

Also comprises quality control, marking and delivery acceptance inspection in the whole construction process,

the quality control comprises the steps of detecting the oil-stone ratio and the mineral aggregate gradation of the slurry mixture every day, and performing pre-control detection on the pendulum friction coefficient, the construction depth and the water seepage coefficient of the finished pavement in time after the slurry mixture is naturally rolled for one day; and ensuring that the quality of the delivery inspection and acceptance construction meets the specification and design requirements. A6.3 mm controllability sieve mesh is arranged in the mineral aggregate grading detection.

Specifically, the paving thickness is 0.9-2.5 cm. The paving thickness has two conditions, one is a normal paving road section with the thickness of 0.9-1.1 cm, and the other is a micro-surfacing paving with the track depth of less than 1.5cm, namely the thickness of 1.1-2.5 cm.

Wherein, the modified emulsified asphalt used for the micro-surfacing overlay is BCR modified emulsified asphalt, BCR represents blending type cation emulsified asphalt, and BCR classification can be found in the literature published by cunkok et al in 10 months 2007: summary of cationic emulsified asphalt and polymer modified emulsified asphalt. Wherein the emulsified asphalt has a residue content of not less than 62% and a softening point of at least 57 ℃. The preparation of the BCR modified emulsified asphalt needs to determine the demulsification speed of the modified emulsified asphalt according to the activity of the aggregate, the dosage and chemical components of the chemical agent, the acid value of the base asphalt and the construction air temperature condition. The mixture comprises 90-92 parts by weight of aggregate, 0-2 parts by weight of cement and 6 parts by weight of modified emulsified asphalt. The aggregate specification is 0-3mm, 3-5mm and 5-8 mm. The aggregate and the mineral powder are made of basalt.

Selection of the raw materials:

1, modified emulsified asphalt:

TABLE 1 test details of modified emulsified asphalt

The modified emulsified asphalt used for the micro-surfacing overlay is special BCR modified emulsified asphalt for micro surfacing, wherein the content of emulsified asphalt residues is not less than 62%, and the softening point of the residues is not lower than 57 ℃.

2, cement: the model is P.O42.5 common silicate, the initial setting time of cement is 191min, and the final setting time is 292 min.

3, aggregate: the MS-3 type mixture is prepared by adopting 0-3mm, 3-5mm and 5-8mm of all basalt, the sand equivalent of the synthesized mineral aggregate is less than 4.75mm, and the requirement that JTG F40-2004 'Highway asphalt pavement construction technical specification' is not less than 65% is met.

TABLE 2 examination item details of coarse aggregate

Design of mix proportion

1. The specific mixing ratio is as follows:

table 3 details of the mixing ratio

2. The grading curve of table 3 is shown with reference to fig. 1.

3. Cohesive force test: the cohesive force test is used for determining the initial setting and open traffic time of the mixture, and according to the proportion determined by the test, the cohesive force test is carried out under the conditions that the indoor temperature is 22 ℃ and 3 ℃ and the relative humidity is 45% and 5%, and the result proves that the proportion can ensure that the traffic is opened within 1 hour and can meet the requirement.

TABLE 4 detailed values of cohesion values

4. Wet wheel wear test results:

the wet wheel abrasion test is used for detecting the lowest oil-stone ratio in the mixture and detecting the compatibility and the water damage resistance of a system, and the WTAT value (soaking for 1 h) specified in the technical Specification for road asphalt pavement construction is less than 540g/m ². The ideal mixture proportion is selected from the previous tests of mixing time, cohesive force and the like, and the asphalt-stone ratio is 6.2 percent (equivalent to 10 percent of the dosage of emulsified asphalt) and the dosage of asphalt is changed up and down at intervals of 0.5 percent to determine various proportions of raw materials used in the wet wheel abrasion test:

TABLE 5 Wet wheel abrasion test Specification

5. The test result of the load wheel is as follows:

the load wheel pressure test is to determine the upper limit of the modified emulsified asphalt dosage in the mixture and prevent the oil bleeding and the deformation after rolling in the construction. The same as wet wheel abrasion, the ratio of oilstone is 6.2%, the asphalt dosage is changed up and down at intervals of 0.5%, and the LWT value of various load wheel pressures of the raw materials used for the load wheel pressure test is determined to be less than 450g/m ²。

TABLE 6 load wheel test results

6. Determining the use amount of asphalt:

referring to FIG. 2, the test was repeated as required, and 1h wet wheel wear values and sand adhesion values for different asphalt dosages were plotted as a relationship curve, respectively. The abrasion value is close to 540g/m ²The amount of asphalt used as the minimum oilstone ratio Pbmin was 5.5%, and the sand adhesion amount was 450g/m ²The amount of asphalt used is taken as the maximum oilstone ratio P _bmaxAt 7.2% an alternative range of oilstone ratio of 5.5% to 7.2% was obtained. According to past experience and actual traffic conditions, an appropriate oilstone ratio is selected to be 6.0 percent in a selectable range of the oilstone ratio, namely the dosage of the emulsified asphalt is 9.6 percent.

And (5) verifying the proper asphalt dosage, and checking the wet wheel abrasion index of the mixture after soaking for 6d according to the selected asphalt dosage.

TABLE 7 test results

According to the past experience and the mix proportion design test result, on the basis of fully considering the characteristics of climate and traffic, the micro-surfacing proportion of the engineering construction is determined to be stone: asphalt: water = 100: 6.0: 5.5, the asphalt content of the modified emulsified asphalt is 62.8 percent, namely the using amount of the modified emulsified asphalt is 9.6 percent.

The invention carries out deep research and improvement aiming at the prior micro-surfacing construction technology, and solves the problems of uneven appearance, smooth road, uneven joint, surface scratch and oil bleeding after the original micro-surfacing construction technology is paved, unstable quality in the process of passing social vehicles for one month and the like. Has better popularization value.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that may be made by those skilled in the art within the technical scope of the present invention will be covered by the scope of the present invention.

Claims

1. A micro-surfacing overlay construction method suitable for pavement preventive maintenance is characterized by comprising the following steps: the method comprises the following steps: step one, preparation before construction: the method comprises the steps of raw material preparation and mechanical preparation; the raw materials comprise coarse aggregates, fine aggregates, modified emulsified asphalt, fillers and additives;

step two, treating the diseases of the original road surface: investigating the original road surface in advance, and performing crack pouring or repairing treatment on longitudinal and transverse cracks of the old road surface according to the properties and the width of the cracks;

step four, lapping and treating longitudinal and transverse seams:

during paving operation, longitudinally lapping a new pavement which is 1-2 mm higher than a lapping surface, manually and flatly jointing the new pavement by using a shovel, enabling the longitudinal lapping surface to be open for traffic and to be rolled and molded, controlling the seam flatness within 3mm, transversely lapping, paving an iron sheet on the lapping surface to be level with a transverse seam, starting a mixer of a seal car to start mixing slurry mixture, and when the slurry mixture is discharged to a position above 1/2 of the height of a screw propeller of a paving box, the seal car starts to move forwards and is rapidly adjusted to a paving set thickness;

step five, processing the bridge expansion joint:

when an expansion joint of a bridge is crossed, iron sheets are adhered by using an adhesive tape to protect the expansion joint with the whole paving width, so that the expansion joint is prevented from being polluted by slurry mixture, the paving thickness is reduced to 0.8cm or below when a sealing vehicle is paved to about 1m in front of the expansion joint, and the paving thickness is timely adjusted to 1.2cm after the sealing vehicle drives to the expansion joint for 1 m;

and step six, opening traffic.

2. The method of claim 1, further comprising quality control, marking and acceptance inspection during the overall construction process,

the quality control comprises the steps of detecting the oil-stone ratio and the mineral aggregate gradation of the slurry mixture every day, and performing pre-control detection on the pendulum friction coefficient, the construction depth and the water seepage coefficient of the finished pavement in time after the slurry mixture is naturally rolled for one day;

3. The method for constructing a micro-surfacing overlay suitable for the preventive maintenance of a pavement according to claim 1, wherein the paving thickness is 0.9-2.5 cm.

4. A method of constructing a micro-surfacing overlay suitable for the preventive maintenance of a road surface according to claim 1, wherein the modified emulsified asphalt used in the micro-surfacing overlay is BCR modified emulsified asphalt, wherein the content of the residue of the emulsified asphalt is not less than 62%, and the softening point of the residue is at least 57 ℃.

5. The method of claim 4, wherein the BCR modified emulsified asphalt is prepared by determining the demulsification rate of the modified emulsified asphalt according to the activity of the aggregate, the dosage and chemical composition of the chemical agent, the acid value of the base asphalt and the construction air temperature condition.

6. The method of claim 1, wherein the mixture comprises 90-92 parts by weight of aggregate, 0-2 parts by weight of cement, and 6 parts by weight of modified emulsified asphalt.

7. The method of claim 6, wherein the aggregate size is one or more of 0-3mm, 3-5mm and 5-8 mm.

8. A method of constructing a micro-surfacing overlay suitable for the preventive maintenance of a pavement according to claim 1, wherein a 6.3mm controlling mesh is provided in the mineral composition test.

9. The method of claim 1, wherein the aggregate and the mineral powder are made of basalt.

10. The method for constructing the micro-surfacing overlay suitable for the preventive maintenance of the pavement according to claim 1, wherein in the sixth step, the demulsification time of the slurry mixture is controlled within 3-4min, the demulsification is started, the forming is performed for 10min, the condition of marking the cold paint is met within 1 hour, and the social vehicles are naturally rolled after 1 hour of open traffic.