CN114716833A

CN114716833A - Modified asphalt for ultrathin overlay, asphalt mixture and interlaminar treatment method

Info

Publication number: CN114716833A
Application number: CN202210299798.9A
Authority: CN
Inventors: 刘继法; 任继仓; 卢高书; 陈建斌; 赵全满; 张涛; 李科; 孟伟; 王潇; 底思祥; 王庶华; 井硕; 向童; 尹斐斐
Original assignee: Tai'an Highway Planning And Design Institute; Shandong Jianzhu University
Current assignee: Tai'an Highway Planning And Design Institute; Shandong Jianzhu University
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2022-07-08

Abstract

The invention relates to modified asphalt for an ultrathin overlay, an asphalt mixture and an interlaminar treatment method. The modified asphalt comprises, by weight, 100 parts of raw material matrix asphalt, 0.3-1.2 parts of micro carbon fiber, 3-8 parts of SBS modifier, 0.1-0.5 part of stabilizer, 1-5 parts of extract oil and 0.2-0.7 part of warm mixing agent. The asphalt mixture comprises 6-7 parts of modified asphalt, 92-94 parts of aggregate and 0.2-0.6 part of cellulose. The high-temperature deformation resistance of SBS modified asphalt is improved, and the viscosity and toughness index of the asphalt can be effectively improved; meets the pavement performance requirement of the ultrathin cover surface.

Description

Modified asphalt for ultrathin overlay, asphalt mixture and interlaminar treatment method

Technical Field

The invention belongs to the technical field of road engineering, and particularly relates to modified asphalt for an ultrathin overlay, an asphalt mixture and an interlayer treatment method.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The ultrathin overlay technology is an asphalt overlay paving technology with the thickness of 15-25mm, can effectively and rapidly repair cracks, loosening, polishing and other diseases, and has the characteristics of strong anti-sliding performance, good durability, high bonding strength, low driving noise, good water sealing effect and the like. Because the thickness of the ultrathin cover surface is reduced, the temperature is reduced too fast during construction, so that the mixture is not compacted sufficiently, and the problems of interlayer damage, water damage, poor durability and the like caused by insufficient interlayer shearing resistance are easily caused.

SBS (styrene-butadiene block copolymer) modified asphalt is in great demand at present, excellent high and low temperature performance of the SBS modified asphalt is widely accepted by the market, and the SBS modified asphalt becomes a mainstream ultrathin overlay paving material at present, but the SBS modified asphalt serving as ultrathin overlay asphalt still has the problems of insufficient viscosity and toughness.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide modified asphalt for an ultrathin overlay, an asphalt mixture and an interlaminar treatment method. The invention provides warm-mix modified asphalt, an asphalt mixture and an interlaminar treatment technology, wherein the dynamic viscosity of the warm-mix SBS/MCF modified asphalt at 60 ℃ can reach more than 20000 Pa.s; the asphalt mixture has good water stability, high temperature stability, high low temperature cracking resistance and high fatigue performance, and may be used as paving material for ultrathin covering to raise the road performance obviously. Meanwhile, the invention provides an interlayer treatment technology which can effectively improve the fatigue performance and the interlayer shear strength of the pavement under the external load.

In order to solve the technical problems, the technical scheme of the invention is as follows:

in a first aspect, the modified asphalt for the ultrathin overlay comprises, by weight, 100 parts of raw material matrix asphalt, 0.3-1.2 parts of Micro Carbon Fiber (MCF), 3-8 parts of SBS modifier, 0.1-0.5 part of stabilizer, 1-5 parts of extract oil and 0.2-0.7 part of warm mixing agent.

The modified asphalt provided by the invention, the SBS/MCF modified asphalt prepared by MCF and SBS composite modification, can improve the viscosity and toughness of the asphalt, optimize the interface structure of the SBS modified asphalt and improve the low temperature and fatigue properties of the asphalt and the asphalt mixture. The asphalt mixture prepared by SBS/MCF composite modification can effectively prevent the expansion of cracks in the asphalt mixture, reduce the rutting and fatigue damage of the ultrathin overlay, and obviously prolong the service life of the ultrathin overlay.

However, the thickness of the ultrathin cover surface is thinner, so that the temperature is reduced too fast during construction, the mixture is not compacted sufficiently, and the problem of construction compaction can be effectively solved by adding the warm mixing agent.

Meanwhile, the thickness of the ultrathin cover surface is reduced, so that the interlayer shear stress is obviously increased under the action of external vehicle load, and the interlayer bonding fails. The invention provides an interlayer treatment technology corresponding to an ultrathin cover surface technology, which can solve the problem of interlayer damage of the ultrathin cover surface.

In some embodiments of the invention, the asphalt comprises, by weight, 100 parts of raw material matrix asphalt, 0.6-1.0 part of micro carbon fiber, 5-8 parts of SBS modifier, 0.1-0.3 part of stabilizer, 1-3 parts of extract oil, and 0.4-0.6 part of warm mixing agent. According to the invention, the proper mixing amount of the SBS modifier, the micro-carbon fibers, the stabilizer, the extracted oil and the warm mixing agent is selected, and the mixing amount of the SBS modifier and the micro-carbon fibers can effectively improve the viscosity and toughness of the asphalt.

In some embodiments of the present invention, the micro carbon fiber has a specification type of 1400-1600 mesh and a density of 1.5-2g/cm³The tensile strength of the micro carbon fiber is 4.5-5GPa, and the elastic modulus of the micro carbon fiber is 220-240 GPa; preferably, the specification type of the micro-carbon fiber is 1500 meshes, and the density of the micro-carbon fiber is 1.8g/cm³The tensile strength of the micro carbon fiber is 4.9GPa, and the elastic modulus of the micro carbon fiber is 230 GPa.

The Micro Carbon Fiber (MCF) is black powder, has the carbon content of more than 95 percent, has high strength and high modulus, has the advantages of less defects, large specific surface area and large length-diameter ratio, and has the characteristics of low density, high modulus, high strength, strong electrical and thermal conductivity, compact structure and the like.

In some embodiments of the invention, the base asphalt is 70# base asphalt, 90# base asphalt; preferably Qinhuang island 70# base asphalt.

In some embodiments of the invention, the SBS modifier is a styrene-butadiene block polymer; further, the styrene-butadiene block polymer model is linear T6302 SBS, styrene: the butadiene block ratio is 3:7, the molecular mass is 100000, and the tensile strength is more than 18.0 MPa. The SBS modifier is a thermoplastic elastomer.

In some embodiments of the invention, the stabilizer is a WDJ4H type stabilizer.

In some embodiments of the invention, the extract oil is an iran extract oil.

In some embodiments of the invention, the warm-mix is an APTL warm-mix.

In a second aspect, the method for preparing modified asphalt according to the first aspect comprises:

heating the matrix asphalt, then adding the extract oil to obtain a mixture A, and heating the mixture A;

under the condition of heat preservation, adding an SBS modifier and micro-carbon fibers into the mixture A to obtain a mixture B;

and under the condition of heat preservation, adding a stabilizer and a warm mixing agent into the mixture B to obtain the modified asphalt.

In some embodiments of the invention, the base asphalt is heated to a temperature such that it is in a fluid state at 150-.

In some embodiments of the invention, the temperature of the heating after the addition of the extract oil is 170-190 ℃.

In a third aspect, the asphalt mixture comprises, by mass, 6-7 parts of the modified asphalt of the first aspect, 92-94 parts of aggregate, and 0.2-0.6 part of cellulose.

The asphalt mixture in the invention is also called modified asphalt mixture.

In some embodiments of the present invention, the modified asphalt comprises the following raw materials, by mass, 6.5 to 7 parts of the modified asphalt according to the first aspect, 92.5 to 93.2 parts of aggregate, and 0.3 to 0.5 part of cellulose.

In some embodiments of the invention, the aggregate comprises 15-20 parts by mass of raw fine aggregate, 60-70 parts by mass of coarse aggregate, and 3-10 parts by mass of mineral powder; further, the aggregates comprise 17-19 parts by mass of raw material fine aggregates, 63-68 parts by mass of coarse aggregates and 5-8 parts by mass of mineral powder; furthermore, the fine aggregate is sand and stone chips, and the coarse aggregate is basalt broken stone.

In some embodiments of the invention, the cellulose is one or more of lignin, polyester fiber, basalt fiber; the cellulose is a mixture of lignin, polyester fiber and basalt fiber, and the mass ratio of the lignin to the polyester fiber to the basalt fiber is 1:2: 2; further the cellulose is lignin.

In a fourth aspect, the method for preparing the asphalt mixture according to the third aspect comprises:

and heating and mixing the aggregate and the cellulose, mixing the mixed mixture with the modified asphalt, and finally adding the mineral powder to obtain the asphalt mixture.

In a fifth aspect, the treatment structure between the ultrathin cover layers sequentially comprises a first modified asphalt layer, a gravel layer, a geogrid and a second modified asphalt layer from inside to outside, wherein the gravel layer is embedded into the first modified asphalt layer, and the first modified asphalt layer and the second modified asphalt layer are the modified asphalt of the first aspect.

The ultrathin overlay has the structural characteristics that the gravel layer and the geogrid are selectively added, so that the problem of interlayer bonding failure of the asphalt mixture can be solved.

In some embodiments of the invention, the crushed stone layer is limestone crushed stone; the geogrid is a single-layer bidirectional basalt fiber geogrid. The granularity of the limestone macadam is 5-10 mm. The material of rubble and the material of geogrid are favorable for improving the ability of interlaminar shear stress.

In a sixth aspect, a method for interlayer treatment of an ultrathin cover surface comprises:

firstly, spraying modified asphalt;

secondly, spreading broken stones on the basis of the first modified asphalt layer, and rolling the broken stones;

laying a single-layer bidirectional basalt fiber geogrid on a construction surface of the crushed stone;

and spraying modified asphalt on the construction surface of the single-layer bidirectional basalt fiber geogrid cloth.

The interlayer treatment technology provided by the invention can obviously improve the interlayer bonding performance and effectively improve the interlayer shear strength of the asphalt pavement. And after the interlayer treatment construction is finished, performing ultrathin cover construction. The ultrathin overlay construction is to pave a layer of the modified asphalt mixture with the thickness of 15-25mm after interlayer treatment is finished. The ultrathin overlay construction after the modified asphalt is spread is carried out according to technical Specification for road asphalt pavement construction (JTG F40-2004).

In some embodiments of the present invention, the modified asphalt previously sprinkled has a sprinkling density of 0.4L/m²～0.6L/m²。

In some embodiments of the present invention, the spreading density of the limestone macadam is 4-6 kg/m²。

In some embodiments of the invention, the modified asphalt layer sprinkled on the geogrid cloth has a distribution density of 0.4L/m²～0.6L/m²。

One or more technical schemes of the invention have the following beneficial effects:

the MCF plays a role in reinforcing the asphalt and the SBS, so that the high-temperature deformation resistance of the SBS modified asphalt can be improved, and the toughness index of the asphalt can be effectively improved;

the modified asphalt mixture prepared by MCF/SBS modified asphalt not only meets the standard requirements, but also has the best construction workability, and can reach the best compaction degree when the ultrathin overlay construction is carried out;

the warm-mixed MCF/SBS modified asphalt can effectively reduce the mixing temperature of the mixture, improve the workability of construction, improve the high and low temperature and fatigue performance of the asphalt mixture and well meet the pavement performance requirement of ultrathin overlay;

the interlayer treatment technology provided by the invention can effectively improve the interlayer bonding performance, so that the interlayer bonding shows excellent shearing resistance, and the pavement performance of the ultrathin cover surface can be obviously improved.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise. The invention will be further illustrated by the following examples

Example 1

A modified asphalt comprises Qinhuang island 70 as raw material^#100 parts of matrix asphalt, 6 parts of linear T6302 type SBS modifier, 0.2 part of WDJ4H type stabilizer, 2 parts of Iran extract oil, 0.8 part of Micro Carbon Fiber (MCF) and 0.5 part of APTL type warm mixing agent.

The specific steps for preparing the modified asphalt are as follows:

1. the matrix asphalt is placed in an oven and heated to 160 ℃ until the asphalt is in a flowing state, then the extract oil is added into the asphalt, and the asphalt is placed in a heat-insulating sleeve and heated to 180 ℃.

2. Keeping the temperature unchanged, slowly adding SBS and micro carbon fiber into the matrix asphalt by adopting a high-speed shearing machine under the condition of 4000rpm, and ensuring that the modifier is uniformly dispersed after shearing for 1 h.

3. Adding the stabilizer under the condition of stirring speed of 650rpm of a stirrer at 180 ℃, stirring for 3h, adding a certain mass of warm-mixing agent, and continuously stirring for 30min to obtain the warm-mixed SBS/MCF modified asphalt.

Example 2

0.4 parts of micro carbon fiber different from example 1, and other components and preparation methods are the same as example 1.

Example 3

1.2 parts of micro carbon fiber different from the embodiment 1, and other components and preparation method are the same as the embodiment 1.

Example 4

5 parts of a linear T6302 type SBS modifier different from that in example 1, and the other components and preparation method are the same as those in example 1.

Example 5

5 parts of a linear T6302 type SBS modifier different from that in example 2, and the other components and preparation method are the same as those in example 1.

Example 6

5 parts of a linear T6302 type SBS modifier different from that in example 3, and the other components and preparation method are the same as those in example 1.

Example 7

7 parts of a linear T6302 type SBS modifier different from that in example 1, and the other components and preparation method are the same as those in example 1.

Example 8

7 parts of a linear T6302 type SBS modifier different from that in example 2, and the other components and preparation method are the same as those in example 1.

Example 9

7 parts of a linear T6302 type SBS modifier different from that in example 3, and the other components and preparation method are the same as those in example 1.

Comparative example 1

In contrast to example 1, no micro-carbon fibers were added.

Comparative example 2

In contrast to example 4, no microcarbon fibers were added.

Comparative example 3

In contrast to example 7, no micro-carbon fibers were added.

The Qinhuang island 70 used in the above embodiment^#The main technical indexes of the matrix asphalt are shown in table 1.

TABLE 1 technical indices of Qinhuang island No. 70 asphalt

The specific test procedures refer to road engineering asphalt and asphalt mixture test procedures (JTGE20-2011), and the basic index test results of the modified asphalt of examples 1-9 and comparative examples 1-3 are shown in Table 2.

TABLE 2 basic index test results of modified asphalt

As can be seen from Table 2, the kinematic viscosity at 60 ℃ gradually increases as the amount of SBS increases, and the kinematic viscosity at 60 ℃ tends to increase and then decrease as the amount of MCF increases, and reaches the highest value at 0.8%. The viscocity and the toughness are gradually increased along with the gradual increase of the SBS mixing amount, and are gradually increased along with the increase of the MCF mixing amount, which shows that the viscocity of the asphalt can be effectively improved by adding the MCF.

Comparative example 2, example 4, example 1, example 7, comparative example 1, example 2, and example 3 were subjected to a multi-stress repeated creep analysis, and the multi-stress repeated creep recovery test was a continuity test performed at stress levels of 0.1kpa and 3.2kpa, respectively, and the high temperature performance of the asphalt material was evaluated well by the obtained test results at a test temperature of 64 ℃. The average strain recovery rate R and average irrecoverable creep compliance can be obtained by MSCR tests. At each stress level 10 cycles were tested, one cycle for 10s, with a 1s creep load phase and a 9s unload recovery phase. R represents the elastic response and stress dependence of the asphalt cement, and represents the unrecoverable strain to stress ratio of the MSCR test. The results are shown in Table 3.

TABLE 3 MSCR test results for modified bitumen

As can be seen from Table 3, the change laws of the accumulated strains with time at the two stress levels are basically the same, and the strains of 6% SBS + 0.8% MCF are significantly lower than those of other composite modified asphalt, which shows that the MCF can improve the high-temperature deformation resistance in the SBS modified asphalt, and the performance is best when the MCF is added into the SBS modified asphalt in an amount of 6% SBS + 0.8% MCF. Under the condition of a certain amount of SBS, a certain amount of MCF is added to effectively reduce the Jnr value of the asphalt cement, and the MCF reaches the lowest value at 0.8%; under the condition that the MCF mixing amount is not changed, Jnr under two stress levels is reduced and then increased along with the increase of the SBS mixing amount, which shows that the improvement of the SBS mixing amount can improve the track resistance of the asphalt, and the effect of 6% SBS + 0.8% MCF is optimal.

Observing and analyzing by Leica fluorescence microscope, analyzing at microscopic angle, and finding

The number of fluorescent spots of 6 percent SBS +0.8 percent MCF is increased, the dispersibility is best, the modification effect is best, no new functional group is generated along with the addition of the micro-carbon fiber for the change of the functional group, and the micro-carbon fiber is not chemically changed but is physically blended.

Example 10

The modified asphalt prepared in the example 1 is used as a cementing material, the asphalt mastic macadam mixture SMA-10 is used as an ultrathin overlay pavement mixture type according to the technical Specification for road asphalt pavement construction F40-2004 in China, and the grading composition and the asphalt dosage of the asphalt mixture are designed by adopting a Marshall design method required by the Specification F40-2004.

A modified asphalt mixture comprises 6.8 parts of modified asphalt prepared in example 1, 0.4 part of cellulose, 18.56 parts of machine-made sand-stone chips with the particle size of 0-3 mm of fine aggregate, 66.82 parts of basalt macadam with the particle size of 5-10mm of coarse aggregate and 7.42 parts of mineral powder. The cellulose is composite fiber (lignin fiber, polyester fiber, basalt fiber are mixed according to the ratio of 1:2: 2).

The preparation method of the modified asphalt mixture comprises the following steps:

1. mixing the screened aggregate and the composite fiber, heating to 160 ℃, putting into a mixing pot, and mixing for 90 s;

2. heating the modified asphalt of example 1 to 150 ℃ and placing the heated modified asphalt in a mixing pot for mixing for 90 s;

3. adding mineral powder, mixing for 90s for 270s totally, and obtaining the modified asphalt mixture.

Comparative example 4

The modified asphalt was the modified asphalt obtained in comparative example 2, compared to example 10.

The modified asphalt mixture prepared in example 10 was subjected to various index tests of the mixture. A dynamic modulus test piece is prepared according to road engineering asphalt and asphalt mixture test procedures, and the data collection of the dynamic modulus is automatically recorded by a basic performance tester SPT in the test process.

The fatigue performance of the modified asphalt mixture is researched by adopting a four-point bending fatigue test under a strain control mode according to road engineering asphalt and asphalt mixture test regulations.

The performance indexes of the modified asphalt mixture are shown in tables 4, 5 and 6.

TABLE 4 example 10 modified asphalt mixture Performance index

TABLE 5 example 10 Effect of dynamic modulus of modified asphalt mixtures with temperature

TABLE 6 example 10 four-point bending test of modified asphalt mixture

1. From table 4, it can be seen that the asphalt mixture has better thermal stability and plastic deformation resistance; the rutting stability is 6774 times/min, which is higher than that of the general SBS modified asphalt mixture, and shows that MCF can improve the high-temperature rutting resistance of the asphalt mixture; the low-temperature bending failure strain (-10 ℃, 5cm/min) reaches 3578 mu epsilon, which is far greater than the specification requirement, so the modified asphalt mixture has good low-temperature performance.

2. Table 5 shows the dynamic modulus data under the action of different temperatures and different frequencies, and the dynamic modulus of 10Hz and 20 ℃ reaches 6352MPa, which shows that the modified asphalt mixture has good mechanical properties.

3. Table 6 shows the fatigue life at different stress levels, which is better for the 6% SBS + 0.8% MCF modified asphalt mixture compared to the conventional 5% SBS modified asphalt mixture.

Therefore, the technical indexes of the modified asphalt and the modified asphalt mixture for the ultrathin overlay can meet the national relevant specifications, the performance is excellent, and the paving requirement of the ultrathin overlay can be met.

Example 11

A treatment technology between ultrathin cover surfaces, wherein the used bonding layer material comprises the following raw materials: single-layer bidirectional basalt fiber geogrid, limestone macadam, and the modified asphalt prepared in example 1.

The single-layer basalt fiber geogrid is manufactured by Shandong Lude manufacturers by taking acid and alkali resistant basalt continuous filaments (RCF) as raw materials, the specification is BCF80-80, the size is 25.4 multiplied by 25.4mm, the heat resistance is-100-280 ℃, and the width is less than or equal to 6 m.

The limestone macadam is produced by tragus stone industry and has the particle size of 5-10mm, the compressive strength of 300Mpa and the firmness index of 1400.

The dosage of the material is 0.8L/m²～1.2L/m²The modified asphalt prepared in example 1 (spread in two times) has a spread amount of limestone macadam of 5-10mm of 4-6 kg/m²And the single-layer basalt fiber geogrid is laid to be 100% of the full cloth area.

An interlayer treatment technique comprising the steps of:

1. uniformly spread 0.4L/m²～0.6L/m²The modified asphalt prepared in example 1;

2. spreading 4-6 kg/m²5-10mm limestone macadam, light in weightRolling for 1-2 times by using the road roller until part (preferably about 1/2) of the broken stone is embedded into the underlying structure and part of the broken stone is exposed above the grating;

3. arranging single-layer bidirectional basalt fiber geogrid cloth on a construction surface;

4. spreading for 0.4L/m²～0.6L/m²The interlayer treatment can be completed by using the modified asphalt prepared in example 1.

And (3) carrying out interlayer damage evaluation on the interlayer treatment technology by using an oblique shear test:

the interlayer evaluation test procedure included:

1. simulating original road surface with SMA-10, making 30cm × 30cm × 5cm rut plate (as lower layer) during test, and coating 0.5L/m²Modified asphalt prepared in example 1, ordinary emulsified asphalt (as a comparative sample) as an interlayer adhesive, 5kg/m of a powder was scattered²Limestone macadam, laying single-layer basalt fiber geogrid, and smearing 0.5L/m²The modified asphalt prepared in example 1 or the ordinary emulsified modified asphalt; the common emulsified asphalt is normal-temperature liquid asphalt produced by a specific process from No. 70 or No. 90 road petroleum asphalt, can be divided into three types of fast cracking, medium cracking and slow cracking according to the demulsification speed, and can be used as adhesive layer oil, permeable layer oil, seal coat oil and the like to be widely applied to the new construction, upgrading and maintenance of roads of national and provincial trunk lines, municipal administration and the like.

2. Paving an ultrathin overlay of 30cm multiplied by 5cm as an upper layer structure according to the method in the step 1, and manufacturing a composite type rut plate test piece of 30cm multiplied by 10 cm;

3. and (3) cutting the composite type track plate obtained in the step (2) into interlayer shear test pieces with the length, width and height of 10cm, 10cm and 10cm respectively.

4. And (3) clamping the test piece by using a clamp under different temperature conditions, and applying vertical pressure on the top surface of the test piece through the UTM until the test piece layers are damaged to obtain the shear strength of the test piece.

The interlaminar shear strength indices are shown in tables 7 and 8. The conventional interlaminar treatment technique in table 8 is an interlaminar treatment method in the technical specification of highway asphalt pavement construction.

TABLE 7 interlaminar shear Strength test results

TABLE 8 results of the shear strength verification test at different temperatures

Table 7 shows that the interlayer treatment technology provided by the present invention greatly improves the interlayer shear strength compared to the conventional treatment technology, and at different temperatures, the modified asphalt prepared in example 1 as a bonding layer material has higher shear strength compared to the common emulsified asphalt, and the modified asphalt prepared in example 1 having high viscosity can provide a larger viscous force to the bonding layer, so that the interlayer shear strength is significantly improved by the interlayer treatment technology and the bonding layer material provided by the present invention.

Table 8 adopts the basic principle and steps of the method for verifying the shear strength of asphalt mixture in the urban road design code to perform interlayer shear verification, and it can be seen that the maximum shear stress in the bonding layer of the composite test piece is always smaller than the allowable shear stress in the oblique shear test at any temperature between the standard load and the overload of 150%, so that the interlayer shear performance meets the requirements.

Example 12

The raw materials of the modified asphalt mixture comprise 6.8 parts of the prepared modified asphalt, 0.4 part of lignin fiber, 18.56 parts of machine-made sand-stone chips with the grain diameter of 0-3 mm of fine aggregate, 66.82 parts of basalt macadam with the grain diameter of 5-10mm of coarse aggregate and 7.42 parts of mineral powder.

The specific steps for preparing the modified asphalt mixture are as follows:

heating the aggregate and the lignin fiber to 160 ℃, putting into a mixing pot, and mixing for 90 s.

Heating the asphalt to 150 ℃, adding the asphalt into a mixing pot, and continuously mixing for 90 s;

adding mineral powder and mixing for 90s to obtain the modified asphalt mixture.

The prepared modified asphalt mixture meets the performance specification for ultrathin finish roads, has superior performance and is completely suitable for paving ultrathin finish roads.

The interlayer treatment technology comprises the following specific steps:

cleaning the pavement before spraying the penetrating layer oil, and uniformly spraying 0.4L/m by adopting an asphalt spraying vehicle for one-time spraying²～0.6L/m²The modified asphalt is uniformly distributed into a thin layer in the whole width of the pavement;

spreading 4-6 kg/m²5-10mm limestone macadam;

laying a single-layer basalt fiber geogrid on a construction surface;

spreading for 0.4L/m²～0.6L/m²The interlayer treatment can be completed by the modified asphalt.

The interlayer treatment technology in the embodiment 12 meets the requirements specified in technical Specifications for construction of asphalt road surfaces of roads, the interlayer shearing resistance is greatly improved, and the interlayer treatment technology is suitable for interlayer treatment of road surfaces.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The modified asphalt for the ultrathin cover surface is characterized in that: the asphalt comprises, by weight, 100 parts of raw material matrix asphalt, 0.3-1.2 parts of micro carbon fiber, 3-8 parts of SBS modifier, 0.1-0.5 part of stabilizer, 1-5 parts of extract oil and 0.2-0.7 part of warm mixing agent.

2. The ultra-thin overlay modified asphalt of claim 1 wherein: the asphalt comprises, by weight, 100 parts of raw material matrix asphalt, 0.6-1.0 part of micro carbon fiber, 5-8 parts of SBS modifier, 0.1-0.3 part of stabilizer, 1-3 parts of extract oil and 0.4-0.6 part of warm mixing agent.

3. As in claimThe modified asphalt for ultrathin finishing coat, according to claim 1, is characterized in that: the specification type of the micro carbon fiber is 1400-1600 meshes, and the density of the micro carbon fiber is 1.5-2g/cm³The tensile strength of the micro carbon fiber is 4.5-5GPa, and the elastic modulus of the micro carbon fiber is 220-240 GPa.

4. The ultra-thin overlay modified asphalt of claim 1 wherein: the matrix asphalt is 70# matrix asphalt and 90# matrix asphalt;

or, the SBS modifier is a styrene-butadiene block polymer.

5. The ultra-thin overlay modified asphalt of claim 1 wherein: the stabilizer is WDJ4H type stabilizer;

or the extract oil is Iran extract oil;

or the warm mixing agent is APTL warm mixing agent.

6. The process for producing modified asphalt according to any one of claims 1 to 5, characterized in that: the method comprises the following steps:

heating the substrate asphalt, then adding extract oil to obtain a mixture A, and heating the mixture A;

under the condition of heat preservation, adding a stabilizer and a warm mixing agent into the mixture B to obtain modified asphalt;

further, the substrate asphalt is heated to be in a flowing state, and the temperature is 150-170 ℃;

further, the temperature of heating after adding the extract oil is 170-190 ℃.

7. An asphalt mixture, which is characterized in that: the composite material comprises the following raw materials in parts by mass: 6-7 parts of modified asphalt as claimed in any one of claims 1-6, 92-94 parts of aggregate, 0.2-0.6 part of cellulose;

further, the aggregate comprises 15-20 parts of raw material fine aggregate, 60-70 parts of coarse aggregate and 3-10 parts of mineral powder by mass;

further, the cellulose is one or more of lignin, polyester fiber and basalt fiber.

8. The method for preparing an asphalt mixture according to claim 7, wherein: the method comprises the following steps:

9. The utility model provides a punishment between ultra-thin top facing layer structure which characterized in that: the modified asphalt comprises a first modified asphalt layer, a gravel layer, a geogrid and a second modified asphalt layer from inside to outside in sequence, wherein the gravel layer is embedded into the first modified asphalt layer, and the first modified asphalt mixture layer and the second modified asphalt mixture layer are the modified asphalt in any one of claims 1-6.

10. A treatment method between ultrathin cover surface layers is characterized in that: the method comprises the following steps:

spraying the modified asphalt of any one of claims 1 to 6;

then spreading broken stones on the basis of the modified asphalt layer, and rolling the broken stones;

sprinkling the modified asphalt of any one of claims 1 to 6 on the construction surface of the single-layer bidirectional basalt fiber geogrid cloth;

further, the distribution density of the modified asphalt to be distributed first is 0.4L/m²～0.6L/m²；

Further, the spreading density of the limestone macadam is 4-6 kg/m²。