阅读说明：本技术 一种压敏早强型微胶囊冷拌沥青混合料及其制备方法 (Pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and preparation method thereof ) 是由 翟栋 杜俊涛 张敏鑫 熊桥梁 聂毅 郏慧娜 李添锦 刘泽涛 曹亦俊 于 2021-10-21 设计创作，主要内容包括：本发明公开了一种压敏早强型微胶囊冷拌沥青混合料及其制备方法,属于沥青技术领域,解决了现有的水性环氧乳化冷拌沥青混合料和溶剂型环氧冷拌沥青混合料由拌合至摊铺碾压的可操作容留时间较短且可控性差的问题。压敏早强型微胶囊冷拌沥青混合料的原料包括：溶剂型冷拌改性沥青、油溶性微胶囊和集料；其中,所述油溶性微胶囊包括芯材和包覆所述芯材的壁材；所述壁材的材料为硬酯酸甘油酯、石蜡、二氧化硅或硅酸盐水泥的一种或多种。本发明的压敏早强型微胶囊冷拌沥青混合料容留时间长,且容留时间可调控,适用性强。(The invention discloses a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method thereof, belongs to the technical field of asphalt, and solves the problems of short operable retention time and poor controllability of the existing water-based epoxy emulsified cold-mix asphalt mixture and solvent-based epoxy cold-mix asphalt mixture from mixing to paving and rolling. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture comprises the following raw materials: solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates; wherein the oil-soluble microcapsule comprises a core material and a wall material coating the core material; the wall material is made of one or more of glyceryl stearate, paraffin, silicon dioxide or portland cement. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture has long holding time, adjustable holding time and strong applicability.)

1. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is characterized by comprising the following raw materials: solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates; wherein the oil-soluble microcapsule comprises a core material and a wall material coating the core material; the wall material is made of one or more of glyceryl stearate, paraffin, silicon dioxide or portland cement.

2. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 1, wherein the raw material of the core material comprises one or more of an explicit curing agent or a latent curing agent.

3. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 1, wherein the raw materials of the core material comprise epoxy resin, an epoxy resin diluent and a curing agent; the curing agent comprises one or more of an explicit curing agent or a latent moisture curing agent.

4. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 1, wherein the mass ratio of the core material to the wall material is 1-4: 1.

5. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 1, wherein the preparation method of the oil-soluble microcapsule comprises the following steps:

step 1, dissolving a surfactant and a coating aid in water to obtain an aqueous solution;

step 2, heating, melting and mixing the coating agent and the core material to obtain a mixed solution, and dispersing the mixed solution into the aqueous solution to emulsify to obtain an emulsion;

and 3, cooling and drying the emulsion to obtain the oil-soluble microcapsule.

6. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 5, wherein in the step 1, the surfactant is one or more of sodium alkyl benzene sulfonate, fatty acid salt or sodium fatty alcohol sulfate; the coating aid is one or more of polyethylene glycol, polyvinyl alcohol, glyceryl monostearate or polyoxyethylene sorbitol.

7. The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture according to claim 1, wherein the raw materials of the solvent-based cold-mix modified asphalt comprise base asphalt, water-in-oil emulsion and additives; the additives include cyanate ester prepolymers, cure accelerators, compatibilizers and modifiers.

8. The pressure-sensitive early strength microcapsule cold mix asphalt mixture according to claim 7, wherein the additive further comprises an epoxy resin and an epoxy resin diluent.

9. The pressure-sensitive early strength microcapsule cold mix asphalt mixture according to claim 7, wherein the water-in-oil emulsion is prepared from a diluent, water and an emulsifier in a ratio of 100: 5-20: 0.1-3 by mass; wherein, the diluent is any one or the combination of solvent naphtha, diesel oil, aviation kerosene, naphtha or fatty ester; the emulsifier is one or combination of glyceryl monostearate, polyoxyethylene sorbitol, ethylene glycol fatty acid ester, propylene glycol fatty acid ester, diethanolamine or triethanolamine.

10. A preparation method of a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, which is used for preparing the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture of claims 1 to 9, and comprises the following steps:

s1, mixing the oil-soluble microcapsule and the solvent type cold-mix modified asphalt at 15-50 ℃ to form microcapsule cold-mix asphalt;

and S2, mixing the microcapsule cold-mixed asphalt with the aggregate at normal temperature to form a pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture, paving the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture on a pavement, atomizing and spraying a proper amount of water, and rolling and curing to open the traffic.

Technical Field

The invention belongs to the technical field of asphalt, and particularly relates to a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method thereof.

Background

The traditional hot-mixed asphalt mixture has high energy consumption and high pollution, so the cold-mixed asphalt mixture is produced at the same time, and the existing cold-mixed asphalt mixture is operated at normal temperature in the mixing and paving process, and has the advantages of energy conservation, emission reduction, good construction workability and the like. At present, the cold-mix asphalt mixture engineering application has the technical problems of weak initial curing strength, poor aggregate wrapping property, short operable retention time from mixing to paving and rolling and the like.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a pressure-sensitive early-strength microcapsule cold mix asphalt mixture and a preparation method thereof, which can solve one of the following technical problems: (1) the operable retention time from mixing to paving and rolling of the existing water-based epoxy emulsified cold-mixed asphalt mixture and solvent-based epoxy cold-mixed asphalt mixture is short; (2) the prior water-based epoxy emulsified cold-mixed asphalt mixture and solvent-based epoxy cold-mixed asphalt mixture have poor controllability on the operable retention time from mixing to paving and rolling; (3) the prior emulsified and solvent-based cold-mix asphalt mixture has weak initial curing strength after being spread and rolled.

The purpose of the invention is mainly realized by the following technical scheme:

on one hand, the invention provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, which comprises the following raw materials: solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates; wherein the oil-soluble microcapsule comprises a core material and a wall material coating the core material; the wall material is made of one or more of glyceryl stearate, paraffin, silicon dioxide or portland cement.

Further, the raw material of the core material comprises one or more of an explicit curing agent or a moisture-sensitive latent curing agent.

Further, the raw materials of the core material comprise epoxy resin, an epoxy resin diluent and a curing agent; the curing agent comprises one or more of an explicit curing agent or a latent moisture curing agent.

Furthermore, the mass ratio of the core material to the wall material is 1-4: 1.

Further, the preparation method of the oil-soluble microcapsule comprises the following steps:

step 1, dissolving a surfactant and a coating aid in water to obtain an aqueous solution;

step 2, heating, melting and mixing the coating agent and the core material to obtain a mixed solution, and dispersing the mixed solution into the aqueous solution to emulsify to obtain an emulsion;

and 3, cooling and drying the emulsion to obtain the oil-soluble microcapsule.

Further, in the step 1, the surfactant is any one or more of sodium alkyl benzene sulfonate, fatty acid salt or sodium fatty alcohol sulfate; the coating aid is one or more of polyethylene glycol, polyvinyl alcohol, glyceryl monostearate or polyoxyethylene sorbitol.

Further, the raw materials of the solvent-based cold-mix modified asphalt comprise base asphalt, water-in-oil emulsion and additives; the additives include cyanate ester prepolymers, cure accelerators, compatibilizers and modifiers.

Further, the additive also comprises epoxy resin and epoxy resin diluent.

Further, when the raw material of the core material comprises one or more of an explicit curing agent or a moisture latent curing agent, the additives in the solvent type cold mix modified asphalt comprise epoxy resin, an epoxy resin diluent, a cyanate ester prepolymer, a curing accelerator, a compatilizer and a modifier; when the raw material of the core material comprises epoxy resin, epoxy resin diluent and curing agent, the additive in the solvent-type cold-mix modified asphalt comprises cyanate ester prepolymer, curing accelerator, compatilizer and modifier, or the additive comprises cyanate ester prepolymer, curing accelerator, compatilizer, modifier, epoxy resin and epoxy resin diluent.

Further, the water-in-oil emulsion is prepared by mixing a diluent, water and an emulsifier in a ratio of 100: 5-20: 0.1-3 by mass; wherein, the diluent is any one or the combination of solvent naphtha, diesel oil, aviation kerosene, naphtha or fatty ester; the emulsifier is one or combination of glyceryl monostearate, polyoxyethylene sorbitol, ethylene glycol fatty acid ester, propylene glycol fatty acid ester, diethanolamine or triethanolamine.

The invention also provides a preparation method of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, which is used for preparing the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, and the preparation method comprises the following steps:

s1, mixing the oil-soluble microcapsule and the solvent type cold-mix modified asphalt at 15-50 ℃ to form microcapsule cold-mix asphalt;

and S2, mixing the microcapsule cold-mixed asphalt with the aggregate at normal temperature to form a pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture, paving the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture on a pavement, atomizing and spraying a proper amount of water, and rolling and curing to open the traffic.

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

1) the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture adopts a new curing induction mechanism, comprises solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates, utilizes the characteristic that the solvent type cold-mix modified asphalt contains water, a diluent and an emulsifier, when the diluent or rolling compaction and the like cause or excite the oil-soluble microcapsules, a wall material can be dissolved and swelled or broken, so that the oil-soluble microcapsules release core material active substances, and the moisture of the solvent type cold-mix modified asphalt, humid air and the humid aggregates induces the moisture of the humid latent curing agent to act together, so that the epoxy resin and cyanate prepolymer are promoted to be cured and crosslinked to form an epoxy resin/polyurethane three-dimensional interconnected space network structure, thereby improving the early curing strength of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture.

2) The adoption of the oil-soluble microcapsule avoids the rapid curing of the epoxy resin, and prolongs the retention time from the mixing to the spreading and rolling. The oil-permeable dissolution rate or the rolling rupture strength is controlled by the thickness of the wall material of the oil-soluble microcapsule, two-layer coating and the like, so that the activation time of the solidification of the oil-soluble microcapsule is adjusted, and the controllability of the holding time is realized.

3) Compared with the conventional curing random reaction of the epoxy asphalt mixture, the microcapsules in the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture release core material active substances, can perform the curing reaction at fixed points, and form a point-to-network crosslinking curing system with polyurethane, so that the curing speed is high, the curing rate is high and the effect is excellent after the microcapsules are excited; and the auxiliary agent on the surface of the aggregate has the function of demulsification on the one hand and can increase the adhesion of asphalt and the surface of the aggregate on the other hand, thereby assisting and improving the curing effect.

4) The strength and the elastic modulus of the asphalt pavement are regulated and controlled according to the proportion of the epoxy resin and polyurethane composite system, the pavement performance after maintenance shows excellent strength and elasticity, and the asphalt pavement is prevented from cracking.

5) The blending and construction temperature of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 15-50 ℃, the workability is good, the pavement can be rolled by vehicles, the microcapsules are further broken to release the core materials, the demulsification of the solvent type cold-mix modified asphalt is accelerated, the volatilization of water and a diluent is accelerated, the curing strength is gradually increased, and the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture can be applied to the field of cold-mix cold-spread pavement engineering.

6) According to the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, the epoxy resin and the epoxy resin diluent are added into the core material of the oil-soluble microcapsule, so that the epoxy resin and the epoxy resin diluent are better contacted with the curing agent, the dispersibility is better, the reaction is faster during curing, and the early-strength curing is higher.

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 practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

Fig. 1 is an SEM image of an oil-soluble microcapsule of example 1 of the present invention;

fig. 2 is a microscopic view of an emulsion in the process of preparing oil-soluble microcapsules of example 1 of the present invention.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.

The invention provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture, which comprises the following raw materials: solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates; the oil-soluble microcapsule comprises a core material and a wall material for coating the core material, wherein the wall material can be one or more layers; the wall material is one or more of glyceride stearate, paraffin, silicon dioxide or portland cement.

The oil-soluble microcapsule is a microcapsule in which the wall material of the microcapsule is dissolved, swollen or broken by a solvent to release the core material.

The oil-soluble microcapsule of the present invention needs a certain strength of the wall material to satisfy the mixing condition when mixed with the solvent-based cold mix modified asphalt and the aggregate, and the wall material may be caused or activated to dissolve, swell or break to release the core material active substance by the diluent or rolling during paving. Therefore, the material of the wall material (hereinafter also referred to as a coating agent) needs to have characteristics of encountering solvent dissolution or swelling and a certain rupture resistance threshold, and therefore, the material of the wall material is controlled to be stearin, paraffin, silica or portland cement.

Specifically, the paraffin wax is 52#, 54#, 56# or 58# paraffin wax.

Specifically, the silica is controlled to a nanoscale size in consideration that the particle size of the silica is too large to facilitate coating of the microcapsule core material.

Specifically, the raw material of the core material may include one or more of an explicit curing agent or a moisture-sensitive latent curing agent.

Specifically, the above-mentioned explicit curing agent is any one of aliphatic polyamine, alicyclic polyamine, modified aromatic amine, or a combination thereof; the moisture-sensitive latent curing agent is a ketimine compound or Schiff base.

Considering that the solvent type cold-mix modified asphalt contains water and the moisture in the humid air and the humid aggregate, the moisture-induced latent curing agent can be hydrolyzed when meeting water, and then the epoxy resin and the cyanate prepolymer are promoted to be cured and crosslinked to form an epoxy resin/polyurethane three-dimensional interconnected space network structure, so that the early curing strength of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is improved. Therefore, the raw material of the core material may preferably be a moisture-sensitive latent curing agent or a combination of an explicit curing agent and a moisture-sensitive latent curing agent.

Considering that too much core material is not conducive to forming a stable clad structure, and too little core material is not conducive to subsequent curing; therefore, the mass ratio of the core material to the wall material is controlled to be 1-4: 1.

Specifically, the preparation method of the oil-soluble microcapsule comprises the following steps:

step 1, dissolving a surfactant and a coating aid in water to obtain an aqueous solution;

step 2, heating, melting and mixing the coating agent and the core material to obtain a mixed solution, and dispersing the mixed solution into the aqueous solution to emulsify to obtain an emulsion;

and 3, cooling the emulsion, and drying to obtain the oil-soluble microcapsule.

It should be noted that, after step 2 and before step 3 of the above preparation method, the method may further include: and adding a coating agent into the emulsion, and continuously and uniformly stirring to obtain the multilayer wall material. The added coating agent is the same as or different from the coating agent added in step 2. Preferably, the additional coating agent is different from the coating agent added in step 2.

Specifically, in the step 1, the surfactant is any one or combination of sodium alkyl benzene sulfonate, fatty acid salt or sodium fatty alcohol sulfate; the coating aid is any one or the combination of polyethylene glycol, polyvinyl alcohol, glyceryl monostearate or polyoxyethylene sorbitol.

In order to avoid the introduction of impurities, in the above step 1, the water may be deionized water.

Specifically, in the step 1, the compatibility of the proper surfactant and the coating aid is favorable for improving the stability of the emulsion and promoting the coating of the microcapsule, so that the mass ratio of the surfactant to the coating aid to the core material is controlled to be 0.8-2: 0.3-1: 2-6.

Specifically, in the step 2, the heating and melting temperature is controlled to be 60 to 80 ℃, for example, 65 ℃, 70 ℃, 75 ℃ and 80 ℃.

Specifically, in the step 2, the emulsifying time is controlled to be 2-8 min.

Specifically, in the above-mentioned method for producing oil-soluble microcapsules, it is necessary to control the order of addition of the respective raw materials, that is, the order of addition in steps 1 to 3, in view of solubility.

Specifically, the raw materials of the solvent-based cold-mix modified asphalt comprise base asphalt, water-in-oil emulsion and additives.

Specifically, the base asphalt may be 70# asphalt or 90# asphalt.

Specifically, the water-in-oil emulsion is prepared by mixing a diluent, water and an emulsifier in a ratio of 100: 5-20: 0.1-3 by mass. Wherein, the diluent is any one or the combination of solvent naphtha, diesel oil, aviation kerosene, naphtha or fatty ester; the emulsifier is one or combination of glyceryl monostearate, polyoxyethylene sorbitol, ethylene glycol fatty acid ester, propylene glycol fatty acid ester, diethanolamine or triethanolamine.

Specifically, in the emulsification process of the water-in-oil emulsion, the stability of the emulsion is not facilitated due to the excessively high emulsification temperature; too low is not conducive to emulsification. Therefore, the emulsifying temperature is controlled to be 50-70 ℃, the shearing rate is 1000-3000 r/min, and the shearing time is 3-10 min.

Specifically, the additives include epoxy resin, epoxy resin diluent, cyanate ester prepolymer, curing accelerator, compatibilizer, and modifier.

Specifically, the epoxy resin is any one of liquid bisphenol a glycidyl ester epoxy resin or polyether epoxy or a combination thereof; the epoxy resin diluent is any one or combination of butyl glycidyl ether, propenyl glycidyl ether or aryl ester glycidyl ether; the cyanate ester prepolymer is any one or combination of a polydiisocyanate or a polymeric polyisocyanate; the curing accelerator is any one or combination of methyldiethanolamine, aminophenol, sodium dihydrogen phosphate, ferric chloride, 2,4, 6-tris (dimethylaminomethyl) phenol, benzyldimethylamine and benzyltriethylammonium chloride; the compatilizer is any one or the combination of sodium dodecyl benzene sulfonate, sodium stearate and fatty alcohol-polyoxyethylene ether sulfate; the modifier is any one or combination of rubber oil, styrene-butadiene-styrene block copolymer, styrene butadiene rubber and high polymer water-absorbing resin.

Considering that the excessive amount of the water-in-oil emulsion in the solvent type cold-mix modified asphalt is not beneficial to volatilization and solidification of the solvent after spreading, and the insufficient amount of the water-in-oil emulsion can not effectively reduce the viscosity of the cold-mix asphalt. Therefore, based on the total mass of the solvent type cold-mix modified asphalt, the mass percent of the oil-in-water emulsion in the solvent type cold-mix modified asphalt is controlled to be 5-20%, the mass percent of the epoxy resin is 3-25%, the mass percent of the epoxy resin diluent is 0.3-8%, the mass percent of the cyanate ester prepolymer is 5-12%, the mass percent of the curing accelerator is 1.5-5%, the mass percent of the compatilizer is 0.5-2.5%, the mass percent of the modifier is 1-7%, and the balance is the matrix asphalt.

Specifically, the preparation method of the solvent-based cold-mix modified asphalt comprises the following steps:

(1) heating the base asphalt to a molten liquid;

(2) and adding the water-in-oil emulsion and the additive into the liquid, and stirring and mixing uniformly at 70-85 ℃ to prepare the solvent type cold-mix modified asphalt.

In one possible design, the raw materials for the core material may include an epoxy resin, an epoxy resin diluent, and a curing agent. Wherein, the curing agent comprises one or the combination of the explicit curing agent or the moisture latent curing agent.

When the raw material of the core material includes an epoxy resin, an epoxy resin diluent, and a curing agent, the epoxy resin and the epoxy resin diluent may be added in small amounts or no amounts to the additives in the raw material of the solvent-based cold mix modified asphalt. That is to say, at this time, based on the total mass of the solvent-based cold mix modified asphalt, the mass percentage of the oil-in-water emulsion in the solvent-based cold mix modified asphalt is controlled to be 5% -20%, the mass percentage of the epoxy resin is 0-25%, the mass percentage of the epoxy resin diluent is 0-8%, the mass percentage of the cyanate ester prepolymer is 5% -12%, the mass percentage of the curing accelerator is 1.5% -5%, the mass percentage of the compatibilizer is 0.5% -2.5%, the mass percentage of the modifier is 1% -7%, and the balance is the matrix asphalt.

Specifically, in the raw materials of the core material, the mass ratio of the epoxy resin, the epoxy resin diluent and the curing agent may be: 2-15: 0.2-1: 0-2.

In the scheme, the oil-soluble microcapsule is coated with part or all of the epoxy resin and the epoxy resin diluent, and the epoxy resin diluent are used as a part of the core material, so that the epoxy resin and the epoxy resin diluent are better contacted with the curing agent, the dispersity is better, the reaction is faster during curing, and the early curing strength is higher.

Specifically, the aggregate is a wet aggregate, the surface of the aggregate (the aggregate can be AC-13 type) is wetted by spraying water or an auxiliary agent aqueous solution before mixing, and the mass percent of the water in the wet aggregate is controlled to be 0.5-2%. The assistant is any one or combination of dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, polyethyleneimine, alkyl polyamine condensate, polyisobutyl succinic anhydride or polyisobutylene succinic anhydride.

Specifically, the preparation method of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture comprises the following steps:

s1, mixing the oil-soluble microcapsule and the solvent type cold-mix modified asphalt at 15-50 ℃ to form microcapsule cold-mix asphalt;

s2, mixing the microcapsule cold-mixed asphalt with the aggregate at normal temperature to form a pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture, paving the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture on a pavement, atomizing and spraying a proper amount of water, and rolling and maintaining for 10-80 h to open the traffic.

Specifically, in S1, the oil-soluble microcapsules are too large in size to facilitate dispersion of the active material in the cold-mix asphalt and are easily broken, and too small in size to make them difficult to break. Therefore, the average particle size of the oil-soluble microcapsules is controlled to be 10 to 150 μm.

Specifically, in S1, the mass ratio of the oil-soluble microcapsule to the solvent-based cold-mix modified asphalt is controlled to be: 10-30: 70-90. Illustratively, the mass ratio of the oil-soluble microcapsule to the solvent-based cold-mix modified asphalt is as follows: 10-28: 75-90.

Specifically, in S2, the mass ratio of the microcapsule cold-mix asphalt to the aggregate is controlled as follows: 5-10: 90-95.

Specifically, in the above S2, the amount of water sprayed by atomization is too large to be favorable for the adhesion between the asphalt and the aggregate. Therefore, the mass percentage of the water for controlling the atomized spray in the aggregate is as follows: 0 to 2%, for example 0.5% to 2%.

Specifically, in S2, the rolling includes static pressing and vibration pressing.

The holding time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is more than 16 hours, such as 16-30 hours; marshall stability of more than 16 kN.

The pressure-sensitive early-strength microcapsule cold-mix asphalt mixture controls the oil-seeping dissolution rate or the rolling rupture strength by adjusting and controlling the thickness of the wall material of the oil-soluble microcapsule, the two-layer coating and other parameters, thereby adjusting the curing activation time of the oil-soluble microcapsule and realizing the adjustability of the holding time. For example, the wall thickness of the oil-soluble microcapsule can be increased to prolong the retention time.

Compared with the prior art, the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture adopts a new curing induction mechanism, comprises solvent type cold-mix modified asphalt, oil-soluble microcapsules and aggregates, utilizes the characteristic that the solvent type cold-mix modified asphalt contains water, a diluent and an emulsifier, when the oil-soluble microcapsules are caused or excited by a diluent or rolling, the wall materials can be dissolved or broken, so that the oil-soluble microcapsules release core active substances, the moisture of the solvent type cold-mix modified asphalt, the humid air and the humid aggregate together induce the moisture-induced latent curing agent to act, the epoxy resin and the cyanate prepolymer are promoted to be cured and crosslinked to form an epoxy resin/polyurethane three-dimensional interconnected space network structure, and the early curing strength of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is improved.

The adoption of the oil-soluble microcapsule avoids the rapid curing of the epoxy resin, and prolongs the retention time from the mixing to the spreading and rolling. The oil-permeable dissolution rate or the rolling rupture strength is controlled by the thickness of the wall material of the oil-soluble microcapsule, two-layer coating and the like, so that the activation time of the solidification of the oil-soluble microcapsule is adjusted, and the controllability of the holding time is realized.

Compared with the conventional curing random reaction of the epoxy asphalt mixture, the microcapsules in the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture release core material active substances, can perform the curing reaction at fixed points, and form a point-to-network crosslinking curing system with polyurethane, so that the curing speed is high, the curing rate is high and the effect is excellent after the microcapsules are excited; and the auxiliary agent on the surface of the aggregate has the function of demulsification on the one hand and can increase the adhesion of asphalt and the surface of the aggregate on the other hand, thereby assisting and improving the curing effect.

The invention regulates and controls the strength and the elastic modulus of the asphalt pavement according to the proportion of the epoxy resin and polyurethane composite system, and the pavement performance after maintenance shows excellent strength and elasticity, thereby preventing the asphalt pavement from cracking.

The blending and construction temperature of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 15-50 ℃, the workability is good, the pavement can be rolled by vehicles, the microcapsules are promoted to further break to release core materials, the cold-mix asphalt is demulsified to accelerate the volatilization of water and a diluent, the curing strength is gradually increased, and the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture can be applied to the field of cold-mix cold-spread pavement engineering.

Example 1

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) dissolving 2 mass percent of fatty acid salt and 0.5 mass percent of polyoxyethylene sorbitol in deionized water; heating, melting and mixing 1% paraffin 58# and 4% alicyclic polyamine as an emerging curing agent at 60 deg.C, dispersing in the above water solution, emulsifying at 500rpm for 3min to obtain emulsion, cooling, centrifuging, and air drying to obtain oil-soluble microcapsule. The mass ratio of the core material to the wall material of the obvious curing agent is 4: 1. The average particle size of the oil-soluble microcapsules was 60 μm.

(2) Emulsifying diesel oil, water and propylene glycol fatty acid ester in a mass ratio of 100:10:1 to form a water-in-oil emulsion, wherein the emulsifying temperature is 65 ℃, the shearing rate is 1000r/min, and the shearing time is 6 min; heating 90# asphalt to a molten liquid state, adding 8% of water-in-oil emulsion, and additive: 6% of styrene-butadiene rubber, 20% of bisphenol A epoxy resin, 4% of butyl glycidyl ether, 10% of poly diphenylmethane diisocyanate, 2% of 2,4, 6-tri (dimethylaminomethyl) phenol and 2% of sodium stearate are added into the liquid, and the mixture is uniformly mixed at 80 ℃ to prepare the solvent type cold-mixing modified asphalt.

(3) 10 percent of oil-soluble microcapsule and 90 percent of solvent type cold-mixed modified asphalt are mixed at the temperature of 45 ℃ to form the microcapsule cold-mixed asphalt.

(4) Tetradecyl trimethyl ammonium chloride is prepared into an aqueous solution with the mass concentration of 3%, and the aqueous solution is taken to atomize, spray and wet the AC-13 type aggregate, wherein the mass of the aqueous solution is 0.5% of that of the aggregate.

(5) Mixing the wet aggregate and the microcapsule cold-mixed asphalt (the microcapsule cold-mixed asphalt accounts for 7 percent of the total mass of the wet aggregate and the microcapsule cold-mixed asphalt) at normal temperature to uniformly wrap the aggregate with the microcapsule cold-mixed asphalt, thereby obtaining the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture.

(6) After the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is paved on a pavement, both the primary pressure and the secondary pressure are alternately used in a static pressure and vibration pressure mode, and the traffic is opened after the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is rolled and maintained for 12 hours.

As illustrated in fig. 1, is an SEM image of oil-soluble microcapsules; fig. 2 is a microscope image showing an emulsion during the preparation of oil-soluble microcapsules.

In the embodiment, the retention time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 16h, and the Marshall stability is 19 KN.

Example 2

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) dissolving 1 mass percent of fatty acid salt and 0.6 mass percent of polyethylene glycol in deionized water; heating, melting and mixing 1% of glyceryl stearate and 3% of aliphatic ketimine at 70 ℃, dispersing in the aqueous solution, emulsifying for 3min at 300rpm while the aqueous solution is hot to obtain emulsion, adding 0.8% of nano-silicon dioxide, continuously stirring uniformly, cooling, performing centrifugal separation, and air-drying to obtain the ketimine microcapsule serving as the core material. The average size of the oil-soluble microcapsules was 10 μm.

(2) Emulsifying aviation kerosene, water and glycol fatty acid ester in a mass ratio of 100:5:0.1 to form a water-in-oil emulsion, wherein the emulsifying temperature is 50 ℃, the shearing rate is 3000r/min, and the shearing time is 4 min; heating No. 70 asphalt to a molten liquid state, adding 20% of water-in-oil emulsion, and additive: 20% of bisphenol A epoxy resin, 6% of propenyl glycidyl ether, 2% of high-molecular water-absorbing resin, 8% of polyhexamethylene diisocyanate, 3% of sodium dihydrogen phosphate and 1% of sodium dodecyl benzene sulfonate are added into the liquid, and the solvent type cold-mixing modified asphalt is prepared by uniformly stirring and mixing.

(3) And uniformly stirring and mixing 12% of the oil-soluble microcapsules and 88% of solvent type cold-mixed modified asphalt at the temperature of 40 ℃ to obtain the microcapsule cold-mixed asphalt.

(4) Preparing polyisobutylene succinic anhydride into an aqueous solution with the mass concentration of 1%, and atomizing, spraying and wetting the aqueous solution to the AC-13 type aggregate, wherein the mass of the aqueous solution is 2% of that of the aggregate.

(5) Mixing the wet aggregate and the microcapsule cold-mixed asphalt (the microcapsule cold-mixed asphalt accounts for 8 percent of the total mass of the wet aggregate and the microcapsule cold-mixed asphalt) at normal temperature to uniformly wrap the aggregate with the microcapsule cold-mixed asphalt, thereby obtaining the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture.

(6) After the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is spread on a pavement, 2% of water is sprayed in an atomizing mode, the primary pressure and the secondary pressure in a rolling mode are both static pressure and vibration pressure which are alternately used, and the traffic is opened after 3d of rolling maintenance.

In the embodiment, the retention time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 16h, and the Marshall stability is 24 KN.

Example 3

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) dissolving 0.8 mass percent of sodium dodecyl benzene sulfonate and 0.5 mass percent of polyvinyl alcohol in deionized water; heating, melting and mixing 1% of glyceryl stearate, 2% of aliphatic ketimine and 1% of apparent curing agent alicyclic polyamine at 70 ℃, dispersing in the aqueous solution, emulsifying for 3min at 500rpm while the aqueous solution is hot to obtain an emulsion, cooling, centrifuging, and air drying to obtain the core material ketimine and alicyclic polyamine microcapsule. The mass ratio of the core material to the wall material of the oil-soluble microcapsule is 3:1, and the average size of the oil-soluble microcapsule is 20 mu m.

(2) Mixing diesel oil, water and propylene glycol fatty acid ester in a ratio of 100:10:1 to form a water-in-oil emulsion, wherein the emulsifying temperature is 65 ℃, the shearing rate is 1000r/min, and the shearing time is 6 min; heating No. 90 asphalt to a molten liquid state, and mixing 8% of water-in-oil emulsion, additive: 6% of styrene-butadiene rubber, 20% of bisphenol A epoxy resin, 4% of butyl glycidyl ether, 10% of poly diphenylmethane diisocyanate, 2% of 2,4, 6-tri (dimethylaminomethyl) phenol and 2% of sodium stearate are uniformly mixed at the temperature of 80 ℃ to prepare the solvent type cold-mixing modified asphalt.

(3) And (3) uniformly stirring and mixing 16% of the oil-soluble microcapsules and 84% of solvent type cold-mixed modified asphalt at the temperature of 50 ℃ to obtain the microcapsule cold-mixed asphalt.

(4) Tetradecyl trimethyl ammonium chloride is prepared into an aqueous solution with the mass concentration of 2%, and the aqueous solution is taken to atomize, spray and wet the AC-13 type aggregate, wherein the mass of the aqueous solution is 1% of that of the aggregate.

(5) Mixing the wet aggregate and the microcapsule cold-mixed asphalt (the microcapsule cold-mixed asphalt accounts for 7 percent of the total mass of the wet aggregate and the microcapsule cold-mixed asphalt) at normal temperature to uniformly wrap the aggregate with the microcapsule cold-mixed asphalt, thereby obtaining the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture.

(6) After the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is spread on a pavement, 1% of water is sprayed in an atomizing mode, the primary pressure and the secondary pressure in a rolling mode are both static pressure and vibration pressure which are alternately used, and the traffic is opened after 3d of rolling maintenance.

In the embodiment, the retention time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 18h, and the Marshall stability is 28 KN.

Example 4

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) dissolving sodium dodecyl benzene sulfonate with the mass fraction of 1% and polyethylene glycol with the mass fraction of 0.6% in deionized water; heating, melting and mixing 2% of glyceryl stearate, 3% of bisphenol A epoxy resin, 0.6% of propenyl glycidyl ether and 1% of aliphatic ketimine at 70 ℃, dispersing the mixture into the aqueous solution, emulsifying the mixture for 2min at 500rpm while the mixture is hot to prepare an emulsion, adding 0.5% of nano-silicon dioxide, continuing stirring the mixture uniformly, cooling the mixture, performing centrifugal separation, and performing air drying to obtain the epoxy and ketimine composite microcapsule with the core material of epoxy and ketimine. The average microcapsule particle size was 22 μm.

(2) Emulsifying 200 # solvent oil, water and glyceryl monostearate in a mass ratio of 100:15:2 to form a diluent water-in-oil emulsion, wherein the emulsifying temperature is 50 ℃, the shearing rate is 3000r/min, and the shearing time is 5 min; heating No. 70 asphalt to a molten liquid state, and mixing 15% of diluent water-in-oil emulsion, additive: 2% of styrene-butadiene-styrene block copolymer, 5% of polyhexamethylene diisocyanate, 2% of benzyltriethylammonium chloride and 2% of fatty alcohol polyoxyethylene ether sulfate, and uniformly stirring and mixing to prepare the solvent type cold-mix modified asphalt.

(3) The microcapsule cold-mix asphalt is prepared by uniformly stirring and mixing 20% of epoxy and ketimine composite microcapsule and 80% of solvent type cold-mix modified asphalt at the temperature of 50 ℃.

(4) Preparing polyisobutylene succinic anhydride into an aqueous solution with the mass concentration of 1%, and atomizing, spraying and wetting the aqueous solution to the AC-13 type aggregate, wherein the mass of the aqueous solution is 2% of that of the aggregate.

(5) Mixing the wet aggregate and 8% of microcapsule cold-mixed asphalt at normal temperature to enable the aggregate to be uniformly coated with the microcapsule cold-mixed asphalt, and obtaining the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture.

(6) After the mixture is paved on a pavement, 1% of water is sprayed in an atomizing mode, both the primary pressure and the secondary pressure in a rolling mode are alternately used in a static pressure mode and a vibration pressure mode, and the traffic is opened after 1d of rolling maintenance.

In the example, the cold-mix cold-laid asphalt mixture had a retention time of 24 hours and a marshall stability of 25 kN.

Example 5

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) dissolving 1.5 mass percent of fatty alcohol sodium sulfate and 0.4 mass percent of polyvinyl alcohol in deionized water; heating, melting and mixing 2.5% of glyceryl stearate, 5% of bisphenol A epoxy resin and 1% of aryl ester glycidyl ether or 6% of aliphatic polyamine diethylenetriamine at 72 ℃, dispersing into the aqueous solution, emulsifying for 3min at 1000rpm while the solution is hot to prepare an emulsion, adding 0.5% of cement, continuously stirring uniformly, cooling, carrying out centrifugal separation, and carrying out air drying to obtain the epoxy microcapsule and the curing agent microcapsule. The average particle size of the epoxy microcapsules was 40 μm. The average particle size of the curing agent microcapsules was 30 μm.

(2) Emulsifying No. 120 solvent oil, water and triethanolamine according to a mass ratio of 100:20:1.5 to obtain a diluent water-in-oil emulsion, wherein the emulsifying temperature is 60 ℃, the shearing rate is 2000r/min, and the shearing time is 3 min; heating No. 70 asphalt to a molten liquid state, and mixing diluent water-in-oil emulsion 5%, additive: 3% of rubber oil, 10% of poly (toluene diisocyanate), 2% of 2,4, 6-tri (dimethylamino methyl) phenol and 2% of sodium stearate are uniformly mixed at the temperature of 60 ℃ to prepare the solvent type cold-mixing modified asphalt.

(3) Mixing 20% of epoxy microcapsule, 8% of curing agent microcapsule and solvent type cold-mix modified asphalt at the temperature of 15 ℃ to obtain the microcapsule cold-mix asphalt.

(4) Preparing hexadecyl trimethyl ammonium bromide into an aqueous solution with the mass concentration of 2%, and atomizing, spraying and wetting the aqueous solution to the AC-13 type aggregate, wherein the mass of the aqueous solution is 0.5% of that of the aggregate.

(5) Mixing the wet aggregate and the microcapsule cold-mix asphalt (the microcapsule cold-mix asphalt accounts for 6 percent of the total mass of the wet aggregate and the microcapsule cold-mix asphalt) at normal temperature to uniformly wrap the aggregate, thereby obtaining the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture.

(6) After the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is paved on a pavement, both the primary pressure and the secondary pressure are alternately used in a static pressure and vibration pressure mode, and the traffic is opened after 10 hours of rolling maintenance.

In the embodiment, the holding time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 20h, and the Marshall stability is 22 KN.

Example 6

The embodiment provides a pressure-sensitive early-strength microcapsule cold-mix asphalt mixture and a preparation method and application thereof. The percentages hereinafter all refer to mass percentages. The preparation method comprises the following steps:

(1) sodium dodecyl benzene sulfonate 1.2 wt% and polyvinyl alcohol 0.8 wt% are dissolved in deionized water. Heating, melting and mixing 2% of paraffin 56#, 3% of bisphenol A epoxy resin, 0.4% of butyl glycidyl ether and 1% of Schiff base at 70 ℃, dispersing in the aqueous solution, emulsifying at 2000rpm for 4min to obtain an emulsion, adding 1% of cement, continuously stirring uniformly, cooling, performing centrifugal separation, and air-drying to obtain the core material epoxy and Schiff base microcapsule. The average size of the particles of the microcapsules was 150 μm.

(2) Emulsifying aviation kerosene, water and an emulsifier glyceryl monostearate into water-in-oil emulsion according to a mass ratio of 100:20:3, wherein the emulsifying temperature is 50 ℃, the shearing rate is 3000r/min, and the shearing time is 5 min; heating No. 70 asphalt to a molten liquid state, and mixing 12% of water-in-oil emulsion, additive: 2% of styrene-butadiene-styrene block copolymer, 5% of poly (toluene diisocyanate), 1% of aminophenol and 2% of fatty alcohol-polyoxyethylene ether sulfate, and uniformly stirring and mixing to prepare the solvent type cold-mix modified asphalt.

(3) The microcapsule cold-mix asphalt is prepared by uniformly stirring and mixing 25 percent of epoxy and Schiff base microcapsules and solvent type cold-mix modified asphalt at the temperature of 50 ℃.

(4) Preparing polyisobutylene succinic anhydride into an aqueous solution with the mass concentration of 1%, and atomizing, spraying and wetting the aqueous solution to the AC-13 type aggregate, wherein the mass of the aqueous solution is 1.5% of that of the aggregate.

(5) Mixing the wet aggregate and the microcapsule cold-mixed asphalt (the microcapsule cold-mixed asphalt accounts for 5 percent of the total mass of the wet aggregate and the microcapsule cold-mixed asphalt) at normal temperature to uniformly wrap the aggregate with the microcapsule cold-mixed asphalt, thereby obtaining the pressure-sensitive early-strength microcapsule cold-mixed asphalt mixture.

(6) After the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is spread on a pavement, 1.5% of water is sprayed in an atomizing mode, the primary pressure and the secondary pressure in a rolling mode are both static pressure and vibration pressure which are alternately used, and the traffic is opened after 2d of rolling maintenance.

In the embodiment, the retention time of the pressure-sensitive early-strength microcapsule cold-mix asphalt mixture is 28h, and the Marshall stability is 24 KN.

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 can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.