Modified emulsified asphalt and preparation method and application thereof
Technical Field
The invention relates to the technical field of road materials, in particular to modified emulsified asphalt and a preparation method and application thereof.
Background
The thin layer cover is an ultrathin asphalt concrete wearing layer technology, and is mainly used for preventive maintenance of high-grade asphalt or cement pavement and corrective maintenance of slight diseases. Generally, the service life of the highway pavement is at least more than 6 years, but the excellent thin-layer cover surface can effectively prolong the service life of the highway, and the service life can reach more than 8-10 years. Meanwhile, the roughness of the surface of the wearing layer can increase the skid resistance of the wheel, can effectively reduce noise, has better water permeability, can greatly reduce common water mist in rainy days, and improves visibility.
Because the thin-layer mat coat usually does not have great thickness (generally less than 2 cm), and increasingly serious adverse conditions such as high temperature, heavy load, overload and the like, new thin-layer mat coat asphalt pavements often have defects such as rutting, cracking, interlaminar pushing, hugging and the like after being put into use, interlaminar sliding damage is easy to occur, and especially in special road sections such as steep slopes, curves and the like, especially when the thin-layer mat coat is used in bridge deck pavement structures and tunnel composite pavements, the elastic modulus between asphalt mixtures and cement concrete is greatly different, the deformation coordination is poor, and if the interlaminar is not subjected to bonding treatment or is improper, interlaminar detachment is caused by being incapable of bearing strong shear stress in the horizontal direction, so that the interlaminar sliding problem is particularly remarkable. Thus, thin layer overcoating places high demands on the bonding material.
In the asphalt pavement construction specification, general regulations are made for the adhesive materials used for the adhesive layer, the penetrating layer and the lower sealing layer, but specific regulations are not made for the aspects of selection of emulsified asphalt used for controlling interlayer positions, selection of the optimal material dosage and the like. When a specific project is constructed, common emulsified asphalt or SBS modified emulsified asphalt is often used for a common adhesive layer, and the common adhesive layer is easily crushed by a construction vehicle in the construction process to cause damage, so that interlayer adhesion is easily caused to be not up to standard. The poor interlayer bonding state can seriously affect the service performance of various pavement structures, the interlayer treatment effect is poor during construction, sufficient shear strength and bonding strength cannot be provided, interlayer shearing damage is caused, and various diseases appear in the later stage of asphalt pavement. If the bonding strength is improved, the low-temperature performance is easily reduced, namely the ductility is poor in a low-temperature environment, and the construction is not easy. Meanwhile, the existing emulsified asphalt has long demulsification time, after spreading, a construction unit usually needs to wait for a plurality of hours before a paving vehicle can be allowed to enter for paving the mixture, so that the construction efficiency is reduced. That is, it is difficult to achieve the adhesion performance, the low temperature performance and the construction efficiency in the prior art.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention provides modified emulsified asphalt, and a preparation method and application thereof.
The invention provides modified emulsified asphalt, which comprises emulsified asphalt, a modifier and a stabilizer, wherein the modifier consists of natural latex, petroleum resin emulsion and third modified liquid, and the third modified liquid is at least one of neoprene latex, nitrile latex and terpene resin emulsion.
According to the invention, the natural latex, the petroleum resin emulsion and the third modifying liquid are selected for compounding, so that the bonding strength and the low-temperature performance of the emulsified asphalt can be better considered, other complicated modifying steps are not needed, the dosage ratio of the emulsified asphalt to other components is simply adjusted on the basis, and the demulsification speed can be increased, thereby obtaining the modified emulsified asphalt with high bonding strength, good low-temperature performance and high construction efficiency, and the modified emulsified asphalt is suitable for a thin-layer cover surface.
Further, the mass ratio of the natural latex to the petroleum resin emulsion to the third modified liquid is (30-80): 5-10): 1-10.
Further, the mass ratio of the emulsified asphalt to the modifier is 40:60-60:40.
Further, the stabilizer is used in an amount of 0.5% -1.2% of the modified emulsified asphalt. The stabilizer is preferably a sodium vinylsulfonate emulsion.
Further, the third modifying liquid is prepared from (0.5-1) and (0.5-2): (1.5-3) neoprene latex, nitrile latex and terpene resin emulsion.
In a preferred embodiment of the present invention, the modified emulsified asphalt comprises the following components in parts by weight: 40-55 parts of emulsified asphalt, 30-50 parts of natural latex, 0.5-2.5 parts of neoprene latex, 0.5-1 part of nitrile latex, 5-10 parts of petroleum resin emulsion, 1.5-3 parts of terpene resin emulsion and 0.5-1 part of sodium vinylsulfonate emulsion.
Further, the emulsified asphalt is cationic emulsified asphalt. Specifically, the slow-cracking quick-setting cationic asphalt emulsion is prepared by using matrix asphalt, an emulsifying agent and a stabilizing agent (the stabilizing agent is different from the stabilizing agent in the modified emulsified asphalt formula and can be methyl cellulose) as raw materials through an emulsifying process.
Further, the natural latex is a viscous milky white liquid, wherein the solid content of the effective component is 55-65% (the solid content of the effective component is the percentage of the latex content in the emulsion to the total amount of the latex and water, the latex is a natural high molecular compound taking cis-1, 4-polyisoprene as a main component, and the content of rubber hydrocarbon in the component is 91-94%). To prevent natural coagulation, a certain amount of ammonia solution is added to natural latex as a protective agent. Commercially available natural latex is added with ammonia solution. The natural latex used in the examples of the present invention has an aqueous ammonia solution content of about 0.77%.
Further, the content of the cationic chloroprene rubber in the neoprene latex is more than 50 percent.
Further, the nitrile rubber content in the nitrile rubber latex is more than 50%.
Further, the petroleum resin emulsion has a solids content of greater than 60%.
Further, the terpene resin emulsion is a milky phenolic modified terpene resin having a solids content of greater than 60%.
The invention also provides a preparation method of the modified emulsified asphalt. The preparation method provided by the invention comprises the step of mixing the raw material components.
Preferably, in mixing, the emulsified asphalt is mixed with natural latex, then petroleum resin emulsion and neoprene latex, nitrile latex (when both components are included), then stabilizer, and finally terpene resin emulsion (when both components are included) are added.
The equipment used in the mixing may be emulsifying equipment, which may be usually a colloid mill, a homogenizer, a stirrer, or the like.
In a specific embodiment of the invention, the preparation method comprises the following steps:
stirring and mixing the emulsified asphalt and the natural latex at normal temperature, and stirring for 30-60min at the rotation speed of 500-1000rpm by using a stirrer, wherein the stirring temperature is 45-90 ℃;
adding neoprene latex and/or nitrile latex and/or petroleum resin emulsion into the mixed solution, and stirring for 30-60min at 500-1000 rpm;
adding stabilizer, adding terpene resin emulsion, and stirring at 500-1000rpm for 30-60min.
The invention also provides application of the modified emulsified asphalt in a thin-layer cover surface. Specifically, the modified emulsified asphalt is used as a bonding layer of a thin-layer cover surface and is applied in a sprinkling mode.
The invention provides modified emulsified asphalt, a preparation method and application thereof, wherein the adhesive strength and the low-temperature performance of the emulsified asphalt can be better considered by compounding natural latex, petroleum resin emulsion and third modified liquid, and other complicated modification steps are not needed. Meanwhile, the modified emulsified asphalt can accelerate demulsification speed, has the characteristic of no sticking to wheels, allows paving equipment to construct on a sticky layer material, does not influence the quality of the sticky layer due to adhesion of asphalt on a tire in the construction process, causes performance loss, has good bonding strength on the formed sticky layer surface, improves construction efficiency, reduces diseases such as road delamination, fatigue cracking and the like caused by bonding failure, and can keep the road around a construction site clean.
The modified emulsified asphalt can be applied to a thin-layer cover surface, avoids using special integrated construction equipment, breaks through cost limitation, promotes large-scale popularization and application of the technology, has very wide market prospect, can effectively solve the problem of adhering wheels of construction vehicles, improves the use efficiency, has important significance for improving a thin-layer maintenance technical system and the application prospect of the adhesive-layer emulsified asphalt, has certain significance for reducing various diseases and enhancing the usability of a pavement, reduces the generation and development of slippage and reflection cracks between pavement layers, greatly reduces the occurrence of water damage phenomena such as flushing, mud of a bottom of a river, holes of the pavement and the like, improves the service quality and the service life of the asphalt pavement, and saves maintenance cost.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The raw materials and auxiliary materials used in the following examples are commercially available unless otherwise specified. Wherein, each raw material index is as follows:
the emulsified asphalt is cationic emulsified asphalt.
The natural latex is a viscous milky liquid, wherein the content of the latex accounts for 55-65% of the total amount of the latex and water, and the content of the ammonia water solution accounts for 0.77% of the natural latex.
The content of the cationic chloroprene rubber in the neoprene latex is more than 50 percent.
The content of the nitrile rubber in the nitrile rubber latex is more than 50 percent.
The solid content of the petroleum resin emulsion is more than 60 percent.
The terpene resin emulsion is a milky phenolic modified terpene resin with a solids content of greater than 60%.
Example 1
The embodiment provides modified emulsified asphalt, which consists of 45 parts of emulsified asphalt, 45 parts of natural latex, 2 parts of neoprene latex, 1 part of nitrile latex, 5 parts of petroleum resin emulsion, 1.5 parts of terpene resin emulsion and 0.5 part of sodium vinylsulfonate emulsion in parts by weight.
The embodiment also provides a preparation method of the modified emulsified asphalt, which comprises the following specific steps:
stirring and mixing the emulsified asphalt and the natural latex at normal temperature, and stirring for 30min at the rotation speed of 1000rpm by using a stirrer, wherein the stirring temperature is 45 ℃;
adding neoprene latex, nitrile latex and petroleum resin emulsion into the mixed solution, and stirring for 30min at a rotating speed of 1000rpm by using a stirrer;
the sodium vinylsulfonate emulsion was added, then the terpene resin emulsion was added again, and stirred with a stirrer at 1000rpm for 30 minutes.
Example 2
The embodiment provides modified emulsified asphalt, which consists of 40 parts of emulsified asphalt, 50 parts of natural latex, 0.5 part of neoprene latex, 0.5 part of nitrile latex, 6 parts of petroleum resin emulsion, 2 parts of terpene resin emulsion and 1 part of sodium vinylsulfonate emulsion in parts by weight.
The preparation method is the same as in example 1.
Example 3
The embodiment provides modified emulsified asphalt, which consists of 55 parts of emulsified asphalt, 30 parts of natural latex, 1 part of neoprene latex, 1 part of nitrile latex, 9 parts of petroleum resin emulsion, 3 parts of terpene resin emulsion and 1 part of sodium vinyl sulfonate emulsion in parts by weight.
The preparation method is the same as in example 1.
Comparative example 1
This comparative example provides a common commercial emulsified asphalt, i.e., emulsified asphalt before modification.
Comparative example 2
The present comparative example provides a modified emulsified asphalt obtained by mixing 50 parts of emulsified asphalt with 50 parts of natural latex.
Comparative example 3
The comparative example provides a modified emulsified asphalt, which consists of 55 parts of emulsified asphalt, 30 parts of natural latex, 14 parts of petroleum resin emulsion and 1 part of sodium vinyl sulfonate emulsion in parts by weight.
The preparation method is the same as in example 1.
Comparative example 4
The comparative example provides a modified emulsified asphalt, which consists of, by weight, 55 parts of emulsified asphalt, 30 parts of natural latex, 3 parts of neoprene latex, 3 parts of nitrile latex, 8 parts of terpene resin emulsion and 1 part of sodium vinylsulfonate emulsion.
The preparation method is the same as in example 1.
Performance testing
The modified emulsified asphalt provided in each example and comparative example was tested according to the asphalt cement test method specified in the industry standard, highway engineering asphalt and asphalt mixture test procedure, and the performance index results are shown in table 1. The strength of the modified emulsified asphalt was evaluated by a tensile strength test. And evaluating the workability of the modified emulsified asphalt by adopting the mixing time and the mixing state.
TABLE 1 modified emulsified asphalt Performance index
From the results, the softening point of the modified emulsified asphalt evaporation residue provided by the embodiment of the invention is more than 75 ℃, the low-temperature ductility of the emulsified asphalt evaporation residue at 15 ℃ is more than 30cm, the elastic recovery at 25 ℃ is more than 65%, the adhesive force pull strength at 25 ℃ is more than 1.4MPa when the modified emulsified asphalt evaporation residue is used for a pavement adhesive layer, and the modified emulsified asphalt is a modified emulsified asphalt which has high adhesive strength, high demulsification speed, good low-temperature performance and excellent storage stability, and can be used as an adhesive material for a thin-layer cover surface in newly-built or cured pavement.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.