CN104762861A - Semi-flexible pavement based on cold-recycling base of bituminous pavement and construction method of semi-flexible pavement - Google Patents

Abstract

The invention discloses a semi-flexible pavement based on a cold recycled asphalt pavement matrix, which is mainly composed of a large-void matrix mixture and a cement-based slurry obtained by cold regeneration of an old asphalt pavement. The large-void matrix mixture is mainly composed of the following components. Composition: 1.5-3 parts of asphalt emulsion, 2-3 parts of filler, 68-93 parts of old asphalt mixture after crushing, 11-35 parts of coarse aggregate, 3-6 parts of water; cement-based slurry mainly consists of 100 parts of water, 50-60 parts of cement, 8-15 parts of polycarboxylate superplasticizer, 20-30 parts of fly ash, and 10-15 parts of SBR latex are evenly mixed. The invention also provides a construction method of the semi-flexible pavement based on the asphalt pavement cold regeneration matrix. The invention solves the problems of waste of resources and funds and environmental pollution during road surface renovation and reconstruction; it has the advantages of anti-rutting, anti-fatigue, waterproof, wear-resistant, etc., and has significant technical, economic, social and environmental benefits.

Description

A semi-flexible pavement based on asphalt pavement cold recycled matrix and its construction method

technical field

The invention belongs to the technical field of road construction and recycling. Specifically, it relates to a semi-flexible pavement based on a cold recycled asphalt pavement matrix and a construction method thereof.

Background technique

With the extension of the service life of roads, a large number of road surfaces have entered the maintenance and repair period one after another. How to recycle the excavated old pavement materials has become an important problem currently facing. The traditional method is to recycle the old asphalt mixture by cold or heat. However, the road surface built with recycled asphalt mixture is weakened due to the weakening of the bonding force between the mixtures, and the deformation resistance and strength of the road surface are low. , It is easy to cause rutting, wrapping and other diseases on the asphalt pavement. The semi-flexible pavement is a pavement formed by pouring special cement-based mortar into the large-void matrix asphalt mixture. Semi-flexible pavement has higher flexibility than cement concrete pavement and rigidity higher than asphalt concrete pavement. It has the advantages of both asphalt pavement and cement pavement, and is favored at home and abroad.

At present, most of the large-void matrix asphalt mixture of semi-flexible pavement is paved by hot-mixing process. During mixing, the asphalt and aggregate must be heated to 160°C-180°C, which consumes a lot of heat energy and causes environmental pollution. Physical health also causes a certain degree of damage; in addition, under high temperature conditions, the asphalt is prone to aging if the mixing time is too long, resulting in a decrease in the cohesion of the mixture and a decrease in life, thereby affecting the road performance and service life of the asphalt mixture. If the cold recycling of asphalt pavement is combined with semi-flexible pavement, it not only solves the problem of recycling old materials, but also improves the driving comfort and durability of the road surface, which has broad economic and social benefits.

Contents of the invention

The technical problem to be solved by the present invention is: in order to improve the effect of asphalt pavement recycling and prolong the service life of the road, the present invention provides a semi-flexible pavement based on the asphalt pavement cold regeneration matrix and its construction method. The semi-flexible pavement paved by the technical solution of the invention makes full use of the old pavement materials, and improves the pavement strength and driving comfort.

In order to solve the above problems, the technical solution adopted in the present invention is:

A semi-flexible pavement based on cold recycled asphalt pavement matrix, which is mainly composed of large void matrix mixture and cement-based slurry obtained from cold recycled asphalt pavement.

The large void matrix mixture is mainly composed of asphalt emulsion at normal temperature, filler, crushed old asphalt mixture, coarse aggregate and water in the following parts by weight:

Asphalt emulsion: 1.5~3 parts,

Filling: 2~3 parts,

Crushed old asphalt mixture: 68~93 parts,

Coarse aggregate: 11~35 parts,

Water: 3~6 parts;

The cement-based slurry is mainly composed of 100 parts of water, 50-60 parts of cement, 8-15 parts of polycarboxylate superplasticizer, 20-30 parts of fly ash, and 10-15 parts of SBR latex.

Further, the porosity of the cold recycled large-void matrix mixture for the pavement is 20% to 28%, the Marshall stability is not less than 2.5kN, the leakage loss is not more than 0.2%, and the Kentucky scattering loss is not more than 30%. The thickness is 5-12cm.

Further, the fluidity of the cement-based slurry is 10-14s, the compressive strength after 7 days of curing under standard conditions is 10-30 MPa, and the flexural strength after 7 days of curing under standard conditions is greater than 3 MPa.

Further, the asphalt emulsion is one of modified emulsified asphalt, epoxy emulsified asphalt or foamed asphalt.

Further, the percentage of the crushed old asphalt mixture passing through the 2.36mm square hole sieve should not exceed 15% of the total mass.

Further, the filler is ordinary Portland cement.

The present invention also provides a construction method of a semi-flexible pavement based on the asphalt pavement cold regeneration matrix, comprising the steps of:

a. According to the relevant requirements of highway asphalt pavement construction technical specification JTG F40-2004, prepare the base layer and spread the penetration layer oil on it, and then pave the large void matrix mixture pavement formed by cold regeneration of the old asphalt pavement;

b. Pour cement-based grout on the large-void matrix mixture pavement, so that the large voids in the large-void matrix mixture pavement are fully filled with cement grout;

c. Remove excess cement-based grout on the road surface, and open to traffic after sufficient curing.

Compared with the prior art, the present invention has the following positive beneficial effects:

1. The semi-flexible pavement based on the asphalt pavement cold regeneration matrix paved by the present invention solves the problems of waste of resources and funds and environmental pollution during pavement renovation and reconstruction.

2. The semi-flexible pavement paved by the present invention has the advantages of anti-rutting, anti-fatigue, waterproof, wear-resistant, etc. The test results show that the semi-flexible pavement paved using the raw materials, weight ratio and construction method of the present invention meets the requirements of the Ministry of Transport. Promulgate the standard road performance requirements, which can be popularized and applied in the overhaul and reconstruction of highways of all grades.

3. Compared with the existing asphalt pavement cold regeneration or semi-flexible pavement technology, the present invention has the advantages of both, and has the following advantages and excellent results:

(a) The semi-flexible pavement paved by the present invention utilizes the waste materials of the original pavement, and the large-void matrix structure and cement-based grout pouring are all constructed at room temperature, which saves energy and avoids a large amount of greenhouse and poisonous gas emissions, and realizes energy saving and reduction Row.

(b) The pavement cold regeneration matrix paved by the present invention can increase the utilization rate of the old asphalt mixture from 20% to more than 95%, and save asphalt by 20% to 40% compared with paving the hot asphalt mixture matrix with large voids, It saves 80%~95% of stone materials, and can save 30%~50% of funds after comprehensive calculation.

(c) The semi-flexible pavement based on the asphalt pavement cold regeneration matrix paved by the present invention, compared with the traditional cold regeneration, has greatly improved high temperature performance, low temperature performance, water stability, and durability, and meets the needs of high-grade road surface materials Using the technical index requirements, the scope of application of cold regeneration has been expanded.

Detailed ways

The purpose of the present invention will be described in further detail below in conjunction with specific examples, and the examples cannot be repeated here one by one, but the implementation of the present invention is not therefore limited to the following examples.

Example 1

The semi-flexible pavement based on cold recycled asphalt pavement matrix is mainly composed of large void matrix mixture and cement-based slurry obtained from cold recycled asphalt pavement.

Preparation of large void matrix mixture: 82.7 parts of the old asphalt mixture to be pulverized are added to the asphalt pavement cold recycling mixing equipment. Add 8.2 parts of coarse aggregate, add 1.8 parts of cement, stir for 30 seconds and mix well; add 5.5 parts of water, stir for 60 seconds, mix well, add 1.8 parts of modified emulsified asphalt with a concentration of 62%, and mix for 90 seconds to obtain emulsified asphalt cold For the recycled matrix mixture, the Marshall stability is not less than 2.5kN, the leakage loss is not more than 0.2%, and the scattering loss of Kentaburg is not more than 30%.

Preparation of cement-based slurry: add 52.1 parts of water, 5.2 parts of polycarboxylate superplasticizer, 6.3 parts of SBR latex to the mixing equipment, stir quickly for 120s to mix evenly, add 26 parts of cement and 10.4 parts of fly ash while stirring , and stirred for 180s to mix well to prepare a cement-based slurry. The fluidity of the cement-based slurry is 10-14s, the compressive strength after 7 days of curing under standard conditions is 10-30 MPa, and the flexural strength after 7 days of curing under standard conditions is greater than 3 MPa.

The detailed steps of the semi-flexible pavement construction method based on the asphalt pavement cold regeneration matrix of the present embodiment are as follows:

a. According to the relevant requirements of highway asphalt pavement construction technical specification JTG F40-2004, prepare the base layer and spread the penetration layer oil on it, and then transport the prepared old asphalt pavement cold recycled mixture to the construction site, and use special paving equipment Pave into a large void matrix mixture pavement with a void rate of 20%~28%, and the paving thickness is 5-12cm;

b. Pour the prepared cement-based grout on the large void matrix mixture road surface, so that the large voids in the pavement can be fully filled with the grout; the cement grouting truck produced by Henan Gaoyuan Highway Maintenance Equipment Co., Ltd. is recommended for cement grouting, in order to fully pour Vibration equipment may be used to vibrate the pavement to aid in grouting.

c. Remove the excess cement slurry on the road surface, and open the traffic after sufficient curing.

Example 2

The difference between this embodiment and embodiment 1 is:

Preparation of large void matrix mixture: 82.7 parts of the old asphalt mixture to be pulverized are added to the asphalt pavement cold recycling mixing equipment. Add 8.2 parts of coarse aggregate, add 1.8 parts of cement, stir for 30s and mix evenly; add 5.5 parts of water, stir for 60s, mix evenly, add 2.0 parts of foamed asphalt with a concentration of 60%, mix for 60s to make cold recycled matrix mixture , The porosity of the cold recycled matrix mixture is 20%~28%, the Marshall stability is not less than 2.5kN, the leakage loss is not more than 0.2%, and the Kentucky scattering loss is not more than 30%.

Example 3

The difference between this embodiment and embodiment 1 is:

Preparation of large void matrix mixture: 82.7 parts of the old asphalt mixture to be pulverized are added to the asphalt pavement cold recycling mixing equipment. Add 8.2 parts of coarse aggregate, add 1.8 parts of cement, stir for 30s and mix evenly; add 5.5 parts of water, stir for 60s, mix evenly, add 3.0 parts of epoxy emulsified asphalt with a concentration of 50%, and mix for 90s to make a cold recycled matrix Mixture, the porosity of the cold recycled matrix mixture is 20%~28%, the Marshall stability is not less than 2.5kN, the leakage loss is not more than 0.2%, and the Kentaburg scattering loss is not more than 30%.

The above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (7)

1., based on a half-flexible pavement for Bituminous Pavement Cold Regeneration matrix, it is characterized in that, primarily of large interstitial matrix compound and the cement-based grout composition of old asphalt pavement cold renewal,

Described large interstitial matrix compound mixes by following weight portion primarily of the old asphalt mixture after the asphalt emulsion under normal temperature state, filler, pulverizing and coarse aggregate and water:

Asphalt emulsion: 1.5 ~ 3 parts,

Filler: 2 ~ 3 parts,

Old asphalt mixture after pulverizing: 68 ~ 93 parts,

Coarse aggregate: 11 ~ 35 parts,

Water: 3 ~ 6 parts;

Described cement-based grout is primarily of 100 parts, water, and cement 50 ~ 60 parts, polycarboxylate high-efficiency water reducing agent 8-15 part, 20 ~ 30 parts, flyash, SBR latex 10 ~ 15 parts mixes and forms.

2. the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to claim 1 and construction method thereof, it is characterized in that: the void content of the large interstitial matrix compound of described road surface cold renewal is 20% ~ 28%, Marshall stability is not less than 2.5kN, leakage analysis losing is not more than 0.2%, Superpave mix-design loss is not more than 30%, and road surface thickness is 5-12cm.

3. the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to claim 1 and construction method thereof, it is characterized in that: the degree of mobilization of described cement-based grout is 10 ~ 14s, compressive strength after standard conditions maintenance 7d is 10 ~ 30MPa, and the rupture strength after standard conditions maintenance 7d is greater than 3MPa.

4. the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to claim 1 and construction method thereof, is characterized in that: described asphalt emulsion is the one in modified emulsifying asphalt, epoxy mulseal or foamed asphalt.

5. the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to claim 1 and construction method thereof, is characterized in that: the percentage that the old asphalt mixture after described pulverizing accounts for gross mass by the powder fines of 2.36mm square hole screen should be not more than 15%.

6. the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to claim 1 and construction method thereof, is characterized in that: described filler is Portland cement.

7. the construction method of the half-flexible pavement based on Bituminous Pavement Cold Regeneration matrix according to any one of claim 1 to 6, is characterized in that, comprise step:

A, to get out basic unit by the related request of standard specification for construction and acceptance of highway asphalt pavement JTG F40-2004 and spread priming oil thereon, then making is by the large interstitial matrix mixture pavement of old asphalt pavement cold renewal;

B, on large interstitial matrix mixture pavement cement injection based slurries, make the large space in large interstitial matrix mixture pavement fully fill up cement grout;

C, the unnecessary cement-based grout of removing road surfaces, open to traffic after abundant health.