CN108504118B

CN108504118B - RAP asphalt softening fusion regenerant and application thereof

Info

Publication number: CN108504118B
Application number: CN201810444289.4A
Authority: CN
Inventors: 吴超凡; 周艺; 韩庆奎; 张继森; 温广香; 李泉; 罗丽
Original assignee: Hunan Yunzhong Renewable Technology Co ltd
Current assignee: Hunan Yunzhong Renewable Technology Co ltd
Priority date: 2018-05-10
Filing date: 2018-05-10
Publication date: 2020-06-30
Anticipated expiration: 2038-05-10
Also published as: CN108504118A

Abstract

The invention discloses an RAP asphalt softening and fusing regenerant and application thereof, wherein the softening and fusing regenerant comprises, by weight, 40-60 parts of a softening agent, 40-60 parts of a medium fusing agent, 5-10 parts of a surfactant and 5-10 parts of a penetrating agent. By using the regenerant, the consumption of emulsified asphalt can be reduced, the comprehensive road performance such as strength, high-temperature stability, low-temperature crack resistance and the like of a cold-recycling mixture can be improved, and the production cost can be saved.

Description

RAP asphalt softening fusion regenerant and application thereof

Technical Field

The invention relates to the technical field of emulsified asphalt cold regeneration, in particular to an RAP asphalt softening fusion regenerant and application thereof.

Background

The traditional cold recycled asphalt mixture is prepared by taking RAP as 'black stone', the original asphalt content and the performance of the RAP in the material are not considered when a mix proportion test and construction are carried out, the RAP is mixed with emulsified asphalt, new aggregates, an additive and water during production, the actual oil-stone ratio of the obtained cold recycled asphalt mixture is higher, and the problems of insufficient fusion of the new asphalt and the old asphalt exist, so that the water stability, the strength and the high-temperature stability of the recycled mixture are insufficient.

Disclosure of Invention

The invention aims to develop an RAP asphalt softening and fusing regenerant, which can improve the bonding force among cold-recycling mixture particles and the strength of a cold-recycling mixture by softening and dissolving old asphalt on the surface of RAP, fusing the old asphalt in RAP and new asphalt in emulsified asphalt together, regenerating the old aged asphalt and forming a uniform and stable new asphalt interface on an ore aggregate interface.

The invention also aims to provide the application of the RAP asphalt softening and fusing regenerant, and the use of the regenerant can reduce the dosage of emulsified asphalt, improve the comprehensive road performance such as strength, high-temperature stability, low-temperature crack resistance and the like of a cold recycling mixture, and save the production cost.

In order to solve the problems, the invention adopts the technical scheme that:

the invention provides a RAP asphalt softening and fusing regenerant which mainly comprises, by weight, 40-60 parts of a softening agent, 40-60 parts of a medium fusing agent, 5-10 parts of a surfactant and 5-10 parts of a penetrating agent.

The invention further comprises the following preferred technical scheme:

in a preferred scheme, the softening agent is dichloromethane;

in a preferred scheme, the medium fluxing agent is absolute ethyl alcohol;

in a preferred scheme, the surfactant is at least one of hexadecyl trimethyl ammonium chloride or octadecyl trimethyl ammonium chloride;

in a preferred scheme, the penetrating agent is turpentine.

In the invention, the RAP is short for recycled asphalt pavement material.

The application of the regenerant is as follows: the RAP asphalt softening fusion regenerant is prepared from the components at normal temperature, and the components are added in no sequence in the preparation process.

When the additive is used, the additive is directly added into added water during production of cold-recycling mixture, and the additive is added according to 0.5-2% of the total amount of RAP.

The invention has the advantages that:

1. the invention can soften the cold recycled RAP surface old asphalt, so that the old asphalt participates in the oil stone proportioning, the emulsified asphalt consumption is reduced, and the production cost is saved;

2. the invention can fuse new asphalt in emulsified asphalt, fully fuse the new asphalt and the old asphalt, form a uniform and stable new asphalt interface, improve the cohesive force of the cold-recycling asphalt mixture, further improve the comprehensive road performance such as the strength, the high-temperature stability, the low-temperature crack resistance and the like of the cold-recycling asphalt mixture, ensure that the splitting strength reaches more than 1Mpa and the standard dynamic stability reaches more than 3000 times/mm, and meet the technical requirements of asphalt pavement surface layers.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

1. The aged asphalt is recovered from cold recycled RAP according to a method for recovering asphalt from an asphalt mixture (an Abson method) in T0726-2011 of road engineering asphalt and asphalt mixture test procedures (JTG E20-2011), the content and technical indexes of the aged asphalt are determined, the recovered asphalt is prepared into a plurality of asphalt blocks with the size of 10g regular, the asphalt blocks are put into 20mL of softening fusion regenerant, and the volatilization conditions of the softening fusion regenerant and the dissolution state of the asphalt blocks are observed for 1h, 2h, 4h and 24h through volatilization solubility tests of examples 1-11, which are detailed in Table 1.

TABLE 1 softening fusion regenerant volatile solubility test

Wherein the percentages represent the degree of volatilization and dissolution, 0% represents: is not volatilized and dissolved; 100% represents: completely volatilize and dissolve.

The surfactant is at least one of hexadecyl trimethyl ammonium chloride or octadecyl trimethyl ammonium chloride; wherein A: 85-90% of absolute ethyl alcohol and 5-10% of surfactant;

b: 40 to 60 percent of carbon tetrachloride, 40 to 60 percent of absolute ethyl alcohol and 5 to 10 percent of surfactant;

c: 40 to 60 percent of epoxidized soybean oil, 40 to 60 percent of absolute ethyl alcohol and 5 to 10 percent of surfactant;

d: 40-60% of n-heptane, 40-60% of absolute ethyl alcohol and 5-10% of surfactant;

e: ethyl acetate 40-60% + absolute ethyl alcohol 40-60% + surfactant 5-10%;

f: 40-60% of petroleum ether, 40-60% of absolute ethyl alcohol and 5-10% of surfactant;

g: 40 to 60 percent of turpentine, 40 to 60 percent of absolute ethyl alcohol and 5 to 10 percent of surfactant;

h: 40-60% of dichloromethane, 40-60% of absolute ethyl alcohol and 5-10% of surfactant;

i: 40-60% of ammonia water, 40-60% of absolute ethyl alcohol and 5-10% of surfactant;

j: 40 to 60 percent of p-xylene, 40 to 60 percent of absolute ethyl alcohol and 5 to 10 percent of surfactant;

k: 40-60% of ethyl ether, 40-60% of absolute ethyl alcohol and 5-10% of surfactant;

according to the volatile solubility test, the permeability test is continued on B, D, E, F, G, H, I, J, K formula which has better softening and fusing effects and less solvent volatilization.

2. The penetration test mold is prepared from the cold recycled RAP recycled asphalt according to a method of T0604-2011 'asphalt penetration test' in road engineering asphalt and asphalt mixture test specification (JTGE20-2011), 1ml of softening fusion agent is added, and penetration values and penetration difference values of the softening fusion regenerant for 0h, 4h and 24h are measured through permeability tests of examples 1-9, and are detailed in Table 2.

TABLE 2 penetration test of softening and fusing regenerants

According to the penetration test, the softening fluxing agent B, D, G, H, J has a better penetration softening effect. The physical and chemical properties, social and economic properties of the softening fusion regenerant were continuously compared, and are detailed in table 3.

TABLE 3 physicochemical properties, social and economic properties of softening-fusing regenerants

	Flash point/. degree.C	Limit of explosion	Water solubility	Environmental pollution property	Price per ten thousand per ton
						Carbon tetrachloride	-19	Fire extinguishing agent	Slightly soluble	Is provided with	0.35-0.38
N-heptane	1	1-7％	Insoluble matter	Is provided with	1-1.4
						Turpentine oil	30	0.8％	Insoluble matter	Is free of	1.3-1.5
Methylene dichloride	40	Fire extinguishing agent	Insoluble matter	Micro-meter	0.45-0.50
						Para-xylene	25	1-7％	Insoluble matter	Is provided with	0.9-1.2
Surface active agent	100	Is free of	Mutual solubility	Is free of	1.5-2.0
						Ethanol	13	3.5-18.0％	Mutual solubility	Is free of	0.55-0.80

According to the analysis of physical and chemical properties, society and economy, the softening fusion regenerant B, D, J can not meet the requirements of social environment, and the cold-recycling asphalt mixture test is carried out on G, H, G + H three groups of softening fusion regenerants.

Dividing the cold recycled RAP recovered by crushing and screening into three grades of 0-8 mm, 8-15 mm and 15-25 mm, drying the three grades in a 60 ℃ oven for 24 hours, screening, selecting medium-grain grading to determine the blending proportion of 9.5-19 mm of new aggregates according to' engineering design grading range of emulsified asphalt cold recycled mixture in technical Specification for road asphalt pavement regeneration (JTG F41-2008), preparing Marshall emulsified asphalt by using 1.5% of Portland cement with strength grade of 42.5, 4% -6% of drinkable water, 0.5-2% of RAP asphalt softening and fusing regenerant and 2% -4% of independently developed cation cold recycled emulsified asphalt in mass percentage of cold recycled mixture, performing a double-layer multi-step mixing process independently developed by regeneration GmbH (J) in Hunan cloud, and preparing Marshall according to a T9-2011 method in experimental regulation of road engineering asphalt and asphalt mixture (JTG E20-070), the front and back sides are compacted 50 times respectively, after the baking oven curing at 60 ℃ is not less than 40 hours, the front and back sides are compacted 25 times respectively, and demoulding is carried out after the cooling at room temperature is not less than 12 hours, and according to T0711-2011 'asphalt mixture theoretical maximum relative density test', T0708-2011 'compacted asphalt mixture density test (volume method)', and T0716-2011 'asphalt mixture splitting test', asphalt mixture indexes such as theoretical maximum relative density, bulk density, void ratio, splitting tensile strength and the like are measured, which are detailed in tables 4, 5 and 6.

TABLE 4 blending ratio table of softening and fusing regenerants

Softening fusion regenerant	Amount of emulsified asphalt (%)	Softening fusion regenerant (%)
			Blank space	4	0
G	2-3	0.5-2
			H	2-3	0.5-2
G+H	2-3	(0.25-1):(0.25-1)

TABLE 5 softening and fusing regenerant Cold recycled asphalt mixture test

TABLE 6 Cold-recycled asphalt mixture index of softening-fusing-recycling agent of the present invention

As can be seen from tables 4, 5 and 6, the cold-recycling RAP softening and fusing regenerant (G + H) can improve the pavement performance of the cold-recycling asphalt mixture to a greater extent, reduce the consumption of cold-recycling emulsified asphalt and enable the pavement performance of the cold-recycling asphalt mixture to meet the technical requirements of an asphalt pavement surface layer.

Claims

The RAP asphalt softening and fusing regenerant is characterized by comprising, by weight, 40-60 parts of a softening agent, 40-60 parts of a medium fusing agent, 5-10 parts of a surfactant and 5-10 parts of a penetrating agent;

the softener is dichloromethane;

the medium fluxing agent is absolute ethyl alcohol;

the surfactant is at least one of hexadecyl trimethyl ammonium chloride or octadecyl trimethyl ammonium chloride;

the penetrant is turpentine.
2. The use of an asphalt RAP softening fusion regenerant according to claim 1, wherein said regenerant is added to RAP in an amount of 0.5% to 2% of the total RAP mass.
3. The use according to claim 2, wherein the RAP asphalt softening fusion regenerant is added to the added water in the production of cold-mix.