CN108003639B

CN108003639B - Maintenance construction method for asphalt pavement cementation wearing course

Info

Publication number: CN108003639B
Application number: CN201711310453.4A
Authority: CN
Inventors: 戴锋; 屠文杰
Original assignee: Jiangsu Perfect Global Project Material Co ltd
Current assignee: Jiangsu Ruiwendell Transportation Technology Co ltd
Priority date: 2017-12-11
Filing date: 2017-12-11
Publication date: 2020-11-20
Anticipated expiration: 2037-12-11
Also published as: CN108003639A

Abstract

The invention discloses a maintenance construction method of an asphalt pavement cementation wearing course, which comprises the following steps: surveying the spreading amount of the curing agent; cleaning the road surface; pre-treating a road surface; spraying a curing agent; spreading a wearing layer; manually finishing; and (5) performing initial curing. The curing construction method of the invention breaks emulsion after the curing agent is atomized or coated on the original pavement, the heavy naphthenic distilled oil quickly leaks to restore the performance of the old asphalt and repair the early diseases of the original asphalt pavement, and simultaneously the mixture of the matrix asphalt and the tackifier is left on the pavement to form a bonding layer. The repaired original asphalt pavement and the bonding layer jointly form the infiltration and solidification layer. The construction speed is fast, and is efficient.

Description

Maintenance construction method for asphalt pavement cementation wearing course

The technical field is as follows:

the invention relates to the field of asphalt pavement maintenance, in particular to a maintenance construction method for an asphalt pavement cementation wearing course.

Background art:

after the asphalt pavement is built, due to the long-term action of vehicle load, abrasion and natural climate, various diseases such as asphalt aging, performance decline, pavement cracks, pits, ruts, looseness, water seepage, pitted surfaces, insufficient skid resistance and the like gradually appear. In order to prolong the service life of asphalt pavements and improve the driving safety and comfort of the pavements, preventive maintenance methods represented by micro-surfacing, super-sticky wearing layers and the like are widely applied at home and abroad at present. The preventive maintenance method has the functions of delaying disease development, repairing tracks, improving the anti-skid performance of the original asphalt pavement and the like, but cannot repair and improve the aged, loose, water seepage and early net crack of the asphalt on the original pavement. The whole strength of the original pavement is insufficient, so that an overlying wearing layer is easy to wear and peel off, the duration time of the maintenance effect is limited, and the pavement begins to obviously degrade within 2-3 years of use.

The invention content is as follows:

aiming at the problems in the prior art, the invention provides an asphalt pavement curing agent.

The invention also provides a maintenance construction method of the asphalt pavement cementation wearing course.

The specific technical scheme of the invention is as follows:

the asphalt pavement penetration agent is prepared by mixing the following raw materials in parts by weight:

20-40 parts of heavy naphthenic distilled oil;

15-30 parts of petroleum-based asphalt;

1-3 parts of an emulsifier;

0-5 parts of a modifier;

40-65 parts of water.

The invention is further designed in that:

the heavy naphthenic distillate oil in the curing agent is hydrodesulfurized heavy naphthenic petroleum light fraction.

The petroleum base asphalt in the curing agent is No. 70 petroleum base asphalt or No. 90 petroleum base asphalt.

The emulsifier in the penetration enhancer is 18331 type emulsifier; the modifier is SBR styrene-butadiene rubber.

A maintenance construction method of an asphalt pavement cementation wearing course comprises the following steps:

1) surveying the spreading amount of the curing agent;

2) cleaning the road surface;

3) pre-treating a road surface;

4) spraying a curing agent;

5) spreading a wearing layer;

6) manually finishing;

7) and (5) performing initial curing.

Step 1) sampling and analyzing an original road surface when the spreading amount of the curing agent is surveyed, detecting the penetration degree and the ductility of the original road surface asphalt, and determining the spreading amount of the curing agent by combining a detection result and a field 30-minute simulation coating test result;

the spreading amount of the curing agent in the step 1) is 0.3-0.7kg per square meter.

During sampling analysis in the step 1), when at least one of the attenuation proportion of the penetration degree or the ductility is more than 20%, the spreading amount of the curing agent per square meter is ensured to be not less than 0.3 Kg; when at least one of the attenuation proportion of the penetration degree or the ductility is more than 50 percent, the spreading amount of the curing agent per square meter is ensured to be not less than 0.5 Kg.

And 4) when the curing agent is sprayed, filling the curing agent into a spraying vehicle, spraying according to a predetermined spraying amount, and after the curing agent is fully infiltrated and reacted, entering the next construction procedure.

And 5) when the wearing layer is paved, the thickness of the wearing layer is 0.6-1.2 cm.

The wearing layer can also be called a modified asphalt mill wearing layer and is prepared by mixing the following raw materials in parts by weight:

9-15 parts of high-molecular polymer modified high-viscosity emulsified asphalt;

80-90 parts of basalt;

0-1 part of filler;

0-3 parts of Portland cement;

0-8 parts of water.

The filler is limestone mineral powder.

Compared with the prior art, the invention has the following advantages:

1. the invention provides a maintenance construction method of an asphalt pavement cementation wearing course of a cementation agent, wherein the cementation agent is atomized or coated on the original pavement to break emulsion, heavy naphthenic distilled oil is quickly infiltrated to restore the performance of the old asphalt and repair the early diseases of the original asphalt pavement, and simultaneously a mixture of matrix asphalt and a tackifier is left on the pavement to form a bonding layer. The repaired original asphalt pavement and the bonding layer jointly form the infiltration and solidification layer. The construction speed is fast, and is efficient.

2. The infiltration component in the infiltration agent rapidly infiltrates into the original pavement, so that the performance (including penetration degree, ductility, softening point and viscosity) of the aged asphalt in the original pavement is recovered, the early-stage aging diseases of the upper surface layer of the original pavement are repaired, the compactness and flexibility of the asphalt are improved, the infiltration wearing layer is not easy to peel off and wear, and the durability is enhanced.

3. The high-viscosity modified asphalt wearing layer provides the functions of abrasion resistance, crack resistance, water resistance and friction performance guarantee within the following years.

4. The consolidation components in the consolidation agent are reserved between the original pavement and the wearing layer, so that the consolidation wearing layer has better interlayer bonding strength and shear strength compared with the common asphalt wearing layer.

5. By integrating the advantages, the method solves several main weak points of similar wearing layer technology, namely the existence of the permeable-solid layer prolongs the sustainable time of the asphalt pavement maintenance effect to two times, and the sustainable time reaches more than 5 years.

6. In addition, the wearing layer in the prior art cannot be applied to loose and net-cracked original pavement. The infiltration component of the penetration and consolidation agent has a repairing effect on the loosening and net crack diseases of the original pavement, so that the invention has wider applicability to old pavements with different conditions.

Description of the drawings:

FIG. 1 is a schematic structural diagram of the present invention.

In the figure, a-modified asphalt wearing course; b-a solid permeation layer; c-the upper layer of the original pavement repaired by infiltration.

FIG. 2 is a flow chart of the asphalt pavement maintenance construction method of the present invention.

The specific implementation mode is as follows:

the invention is further described below with reference to the accompanying drawings:

as shown in figure 1, the pavement repaired by the asphalt pavement penetration wearing layer has a three-layer structure, and consists of an upper surface layer 1 of an original pavement repaired by infiltration, a bonding layer 2 and a modified asphalt wearing layer 3.

The first embodiment is as follows: preparing the asphalt pavement curing agent:

the asphalt pavement curing agent is prepared by mixing the following raw materials:

heavy naphthenic distilled oil: 300Kg, heavy naphthenic petroleum light fraction (manufactured by Ergon, USA) subjected to hydrodesulfurization is selected.

Petroleum-based asphalt: 200Kg, and No. 70 petroleum base asphalt (or No. 90 petroleum base asphalt) is selected;

20Kg of emulsifier, 18331 type emulsifier (made by Akzo-Nobel of the Netherlands)

30Kg of modifier, styrene butadiene rubber SBR modifier is selected.

550Kg of water.

The preparation process of the asphalt pavement curing agent comprises the following steps: mixing heavy naphthenic distillate oil and petroleum base asphalt to form base oil mixed liquor for heat preservation for later use, then mixing an emulsifier, a modifier and water in proportion to prepare soap solution, and finally producing the base oil mixed liquor and the soap solution together through a colloid mill to form emulsion for later use.

Example two: preparing the asphalt pavement curing agent:

20-40 parts of heavy naphthenic distilled oil;

15-30 parts of petroleum-based asphalt;

1-3 parts of an emulsifier;

0-5 parts of a modifier;

40-65 parts of water.

Heavy naphthenic distilled oil: 250Kg, selecting heavy naphthenic petroleum light fraction (produced by Ergon company in America) which is subjected to hydrodesulfurization;

petroleum-based asphalt: 250Kg, and No. 90 petroleum base asphalt is selected;

15Kg of emulsifier, and 18331 type emulsifier (manufactured by Akzo-Nobel of the Netherlands) is selected;

45Kg of modifier by weight, selected from: styrene Butadiene Rubber (SBR) modifier;

450Kg of water.

Example three: preparing the asphalt pavement curing agent:

heavy naphthenic distilled oil: 350Kg, selecting heavy naphthenic petroleum light fraction (produced by Ergon company in America) subjected to hydrodesulfurization;

petroleum-based asphalt: 100Kg, selecting No. 90 petroleum base asphalt;

28Kg of emulsifier, and 18331 type emulsifier (manufactured by Akzo-Nobel of the Netherlands) is selected;

600Kg of water.

Example four: preparing a modified asphalt wearing layer:

the modified asphalt wearing layer is prepared by mixing the following raw materials for standby:

120Kg of high-molecular polymer modified high-viscosity emulsified asphalt;

850Kg of basalt;

5Kg of filler;

15Kg of Portland cement;

6Kg of water.

The high-molecular polymer modified high-viscosity emulsified asphalt is slow-breaking cationic emulsified asphalt, the content proportion (solid content) of evaporation residues is more than 60%, the softening point of the evaporation residues is higher than 60 ℃, the ductility at 5 ℃ is higher than 80cm, the penetration at 25 ℃ is 60-1201/10 mm, and the dynamic viscosity at 60 ℃ is more than 2500 Pa.s. Wherein the high molecular polymer modifier is styrene butadiene rubber SBR or styrene block copolymer SBS in the proportion of 3-10% in the emulsified asphalt.

The basalt is required to be rolled from stone with high strength and good wear resistance, and the 9.5mm square-hole sieve throughput rate is 100%, the 4.75mm square-hole sieve throughput rate is 70-90%, the 2.36mm square-hole sieve throughput rate is 40-70%, and the 0.075mm square-hole sieve throughput rate is 5-15%.

The filler is limestone mineral powder.

Example five: preparing a modified asphalt wearing layer:

100Kg of high-molecular polymer modified high-viscosity emulsified asphalt;

800Kg of basalt;

10Kg portions of Portland cement;

20Kg of water.

Wherein the selection of the high molecular polymer modified high viscosity emulsified asphalt and the basalt is the same as the fourth embodiment.

Example six: preparing a modified asphalt wearing layer:

110Kg of high-molecular polymer modified high-viscosity emulsified asphalt;

880Kg of basalt;

8Kg of filler;

25Kg of Portland cement.

Wherein the selection of the high molecular polymer modified high-viscosity emulsified asphalt, the filler and the basalt is the same as the fourth embodiment.

Example seven: the maintenance construction method of the asphalt pavement cementation wearing course comprises the following steps:

the maintenance construction method of the asphalt pavement cementation wearing course is roughly shown in figure 2 and comprises the following steps:

step 1), spreading amount survey of a curing agent:

the method comprises the steps of surveying the original pavement, selecting the most representative road section for coring and sampling, uniformly cutting the core sample to 2cm of the surface, heating the core sample indoors, extracting and recovering the core sample by using trichloroethylene, detecting penetration and ductility of the recovered asphalt, comparing the detection result with a new asphalt index (namely the lower limit of the required range of the same index in the existing asphalt pavement construction technical specification) to calculate the attenuation ratio, and using the attenuation ratio as a preliminary basis for determining the distribution amount of the penetration component. The large attenuation ratio indicates that the aging is serious and the required spreading amount is large. When one of the attenuation proportion of the penetration degree or the ductility is more than 20 percent, the spreading amount of the curing agent per square meter is ensured to be not less than 0.3 Kg; when one of the attenuation proportion of the penetration degree or the ductility is more than 50 percent, the spreading amount of the curing agent per square meter is ensured to be not less than 0.5 Kg. And combining the indoor aging test result, carrying out a simulated coating test on the construction section site to determine the absorption rate for 30 minutes, and taking the absorption rate as a direct basis for the spreading amount of the site construction.

Step 2) cleaning the road surface:

the soil, sundries and the like on the original road surface are cleaned, and the road surface can be cleaned by using a sprinkler and a high-power blower. And ensure no water accumulation on the original road surface.

Step 3) road surface pretreatment:

the original pavement must have sufficient structural strength. The original pavement local structure is insufficient in strength, and a proper method is required to be selected for reinforcement according to specific conditions. And when the ruts below 10mm on the original road surface can be directly maintained, and the ruts above 10mm are filled in advance according to specific conditions. Meanwhile, in order to avoid hidden troubles, the defects of crack pouring, road surface pit slot repairing, depression and the like are repaired in advance.

Step 4), spraying a curing agent:

and (3) loading the finished product of the curing agent into an intelligent spreading vehicle or a gravel synchronous spreading vehicle, calibrating the intelligent spreading vehicle according to the pre-measured spreading amount, performing the spreading operation of the original pavement (the spreading amount ranges from 0.3 to 07 kg/square meter), and after 20 to 30 minutes, allowing the curing agent to fully react downwards to enter the next construction procedure. The absorption time of the consolidation agent is influenced by the weather, the speed is higher under the condition of sunny days and sunny days, and the time is prolonged to 40-60 minutes if the sunny days are cloudy days.

Step 5), paving a wearing layer: preparing asphalt wearing layer according to four raw materials and proportion

The method requires the use of an automatic slurry seal paver and comprises the following steps:

1) lofting and scribing: and adjusting the width of the paving box according to the width of the lane to enable the number of construction vehicle trips to be an integer. The width is set out from the curb, and the first car is marked with a running control line from the left side.

2) Charging: the high molecular polymer modified high-viscosity emulsified asphalt, the filler, the basalt, the water, the silicate cement and the like which meet the requirements are respectively loaded into corresponding material boxes of the paver.

3) Paving machine

A. The spreader loaded with the materials is driven to a construction starting point, the trend control line is aligned, the spreader is placed at a working position, the thickness and the camber of the spreading box are adjusted, the rear rubber plate of the spreader is outwards turned, the other three rubber plates are inwards turned, the height and camber adjusting screws of the slideway are adjusted to enable the height and camber of the slideway to meet the spreading thickness required by construction, the periphery of the spreading box is kept to be tightly attached to the original pavement, and a mop cloth is hung;

B. starting the machine after confirming the height or the opening degree of each material door, engaging a clutch of a mixing cylinder, enabling a stirring shaft to normally operate, and starting a spiral material distributor of the paving box;

C. opening each material door control switch to enable the high-molecular polymer modified high-viscosity emulsified asphalt, the filler, the basalt and the water to enter a mixing cylinder, and when the pre-wetted mixture is pushed to an emulsion spraying port, spraying the emulsion; during stirring, the water quantity is further finely adjusted by controlling a switch, so that the asphalt mixture has moderate consistency and is suitable for being paved without flowing (when the ground humidity is higher, less water is needed to be added, even no water is added);

D. adjusting the flow direction of the mixture on the diverter to ensure that the mixture can uniformly flow to the left and the right of the spreading box;

E. when the mixture is uniformly distributed in the full-width range of the paving box, the chassis is started and slowly moves forwards, but the paving amount of the normal-temperature asphalt mixture is basically consistent with the production amount, and the volume of the mixture in the paving box is kept to be about 1/2 of the volume of the paving box. Special care is taken to prevent spillage during construction;

F. when any material on the paver is used up, all switches are immediately closed, so that the mixture in the stirring cylinder is uniformly stirred and is conveyed into the paving box to be paved, and the forward movement is stopped;

G. when the material is added and the material is paved again, the material is retreated 3-4m from the paving end point of the previous vehicle, so that a section of the two sealing layers is overlapped. The raised and over-diluted mixture is scraped, so that the falling caused by inaccurate oil-water ratio during starting is avoided, and the connected stubbles are smooth and regular;

H. and lifting the paving box when the construction is finished, then opening the paver and the paving box out of the road, and cleaning the stirring cylinder and the paving box.

4) Seam treatment

A. And (3) transverse seam treatment: usually, the transverse seam is in a butt joint mode, and the automatic slurry seal paver advances at a slightly slower speed when at a starting point, so that the phenomenon of arching caused by over-thick paving due to excessive mixture in a paving box can be avoided. After a car is paved, a spade is used for shoveling the joint, an iron sheet is paved at the joint and is flush with the tail end of the joint, the paving car is hung on the paving box and is poured to the joint, the paving box is placed on the iron sheet, and after the paver advances, the iron sheet and the mixture on the iron sheet are taken away together.

B. Longitudinal seam treatment:

the construction lanes are constructed successively (from low to high) from the outer side to the central separation zone, during construction, pre-wetting water treatment is firstly carried out at the laid half-width joint, the edge of a laying box is infinitely close to the edge of the laid lane, and the dilute slurry mixture has a certain self-flowing effect, so that the connection of the mixtures of the two lanes is facilitated. If the lap joint is too thick or not well jointed, the lap joint is manually scraped before forming.

Step 6), manual trimming:

after the mixture is spread, manual leveling is immediately carried out, wherein the manual leveling comprises a starting point, a finishing point, a longitudinal joint, an excessively thick part, an excessively thin part or an uneven part, and particularly, scratches generated on the mineral aggregate with the ultra-large particle size are removed and filled as soon as possible.

Step 7) initial curing:

after the mixture of the penetration wearing layer is paved, all vehicles and pedestrians are prohibited from passing through before the traffic is opened. The mixture is generally not required to be rolled by a road roller after being paved. When the emulsion breaking and primary forming mixed material is used in occasions where driving rolling is absent or not available, such as hard road shoulders, parking lots and the like, or in order to meet certain special requirements, a 6-10t rubber-wheel road roller can be used for rolling the emulsion breaking and primary forming mixed material. The traffic can be opened as soon as possible after the requirement of opening the traffic is met.

Closing and opening traffic:

before the construction of the method, the road is generally closed and the traffic is closed.

After the initial curing, the penetration wearing layer needs a period of curing time after the initial setting to gradually harden to the extent that the penetration wearing layer can support the rolling of vehicles, so that the time for opening traffic is longer than the initial setting time, and the vehicles are prohibited from passing in the period so as to avoid leaving the marks of wheels. The time for opening traffic will be determined based on the site temperature, wind speed, etc.

The structure of the constructed pavement is shown in figure 1, which is a modified asphalt wearing layer A, a cementation layer B and an upper pavement layer C repaired by infiltration.

In the invention, the penetration curing agent is atomized and sprayed or coated on the original pavement to break the emulsion. The heavy naphthenic distilled oil has good compatibility and permeability in an asphalt phase, and rapidly seeps downwards under the action of gravity, so that the performance index of surface layer asphalt which is 3-4cm below the surface of the original pavement is recovered, and the original asphalt pavement is firm and flexible. Meanwhile, the mixture of the matrix asphalt and the modifier is retained on the road surface to form a bonding layer, so that the original road surface and the overlying wearing layer are bonded into a whole.

The prior asphalt pavement pre-curing technology only provides a wearing layer or a few technologies for increasing a bonding layer on the basis of the wearing layer. However, since 3-4cm of asphalt on the surface of the original pavement serving as the foundation of the lower part of the wearing course is affected by the external environment for a long time and natural aging is inevitable, the prior art has the following limitations:

1. the viscosity and elasticity of cementing materials (asphalt) in the original pavement are seriously degraded, but the emulsified asphalt adopted by the prior art does not have infiltration capacity, so that the condition cannot be improved, the bonding effect between an overlying maintenance layer and the original pavement is limited, and the durability is further influenced.

2. The situation of insufficient strength such as looseness, microcracks and the like exists in local or whole original pavement, and the displacement is large under the action of load, so that the peeling degradation of the overlying maintenance layer can be accelerated.

3. Based on the above content, the application range of the prior art is relatively narrow, and the road surface is only suitable for a few old roads with ideal road conditions.

According to the field sampling test and comparison before and after implementation, the infiltration depth of the infiltration agent can reach 3-4 cm. The improvement ratio of the asphalt ductility to the depth and the penetration is generally more than 30 percent, so that the asphalt is restored to the level close to that of new asphalt. In the full-scale pavement accelerated loading simulation test, the tested durability is more than 2 times of that of the prior art, namely the expected effective life of the prior art is prolonged from 2-3 years to about 5 years, so that the annual cost of asphalt pavement maintenance is greatly reduced.

Claims

1. A method for maintaining and constructing a cementation wearing course of an asphalt pavement is characterized by comprising the following steps:

1) surveying the spreading amount of the curing agent;

2) cleaning the road surface;

3) pre-treating a road surface;

4) spraying a curing agent;

5) spreading a wearing layer;

6) manually finishing;

7) maintaining at an initial stage;

when the spreading amount of the curing agent is surveyed in the step 1), sampling and analyzing the original pavement, detecting the penetration degree and the ductility of the original pavement asphalt, and determining the spreading amount of the curing agent by combining the detection result and the field 30-minute simulation coating test result;

the curing agent is prepared by mixing the following raw materials in parts by weight: 20-40 parts of heavy naphthenic distilled oil, 15-30 parts of petroleum-based asphalt, 1-3 parts of emulsifier, 0-5 parts of modifier and 40-65 parts of water; the heavy naphthenic distillate oil is hydrodesulfurized heavy naphthenic petroleum light fraction;

when at least one of the attenuation proportion of the penetration degree or the ductility is more than 20 percent, the spreading amount of the curing agent per square meter is ensured to be not less than 0.3 Kg; when at least one of the attenuation proportion of the penetration degree or the ductility is more than 50 percent, the spreading amount of the curing agent per square meter is ensured to be not less than 0.5 Kg;

when the curing agent is sprayed in the step 4), the curing agent is filled into a spraying vehicle and is sprayed according to the predetermined spraying amount, and the curing agent enters the next construction procedure after sufficient infiltration reaction;

the wearing layer paved in the step 5) is formed by mixing the following raw materials in parts by weight: 9-15 parts of high-molecular polymer modified high-viscosity emulsified asphalt, 80-90 parts of basalt, 0-1 part of filler, 0-3 parts of Portland cement and 0-8 parts of water.

2. The method for curing and constructing the asphalt pavement cementation wearing course according to claim 1, which is characterized in that: the petroleum base asphalt in the curing agent is No. 70 petroleum base asphalt or No. 90 petroleum base asphalt.

3. The method for curing and constructing the asphalt pavement cementation wearing course according to claim 1, which is characterized in that: the emulsifier in the curing agent is 18331 type emulsifier; the modifier is SBR styrene-butadiene rubber.

4. The method for curing and constructing the asphalt pavement cementation wearing course according to claim 1, wherein: the spreading amount of the curing agent in the step 1) is 0.3-0.7kg per square meter.

5. The method for curing and constructing the asphalt pavement cementation wearing course according to claim 1, wherein: and 5) when the wearing layer is paved, the thickness of the modified asphalt wearing layer is 0.6-1.2 cm.

6. The method for curing and constructing the asphalt pavement cementation wearing course according to claim 1, wherein: the filler in the wearing layer is limestone mineral powder.