CN102795813A - Dense-graded asphalt concrete with continuous skid-resistant and noise-reduction functions - Google Patents

Abstract

The invention relates to a densely graded asphalt concrete with durable anti-skid and noise reduction functions. It is prepared from coarse aggregate, fine aggregate, filler and asphalt according to the ratio requirements of densely graded asphalt concrete. It is characterized in that: the coarse aggregate is calculated by volume percentage from ordinary coarse aggregate and functional aggregate. : 0% to 50% of ordinary coarse aggregate, 50% to 100% of functional aggregate, wherein the functional aggregate is a core-shell structure consisting of a porous core matrix and an alkaline surface activated shell, and the porous core matrix is composed of Mullite forms a continuous phase as the main mineral phase, and pores are distributed in the continuous phase. The pores are multi-level distributed, and are mainly micron-sized pores; the mineral phase composition of the alkaline surface activation shell is mainly Dicalcium silicate, tricalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite. It has good bearing capacity, good water damage resistance, continuous anti-skid and noise reduction function, good durability, and has wide application prospects.

Description

A densely graded asphalt concrete with continuous anti-sliding and noise reduction functions

technical field

The invention belongs to the field of road building materials, in particular to a densely graded asphalt concrete with continuous anti-skid and noise reduction functions.

Background technique

Asphalt concrete pavement has the characteristics of smoothness, beauty, anti-glare, easy repair, etc., and it is widely used. However, the skid resistance of asphalt concrete pavement gradually decreases as the aggregate is polished, which seriously affects the safety of vehicles. In response to this problem, at present, hard and wear-resistant basalt aggregates are mainly used to replace limestone or granite aggregates to prepare asphalt concrete. However, basalt aggregates also have the problem of smooth surface after the aggregates are polished, and the distribution of basalts is regional. Material costs are higher. Although the open graded wear layer (OGFC) pavement plays a certain role in anti-skid, sound absorption, and noise reduction, the bearing capacity of the OGFC pavement is insufficient and the durability is poor. At the same time, high-viscosity asphalt must be used, which is expensive and unfavorable for promotion. However, there is also the problem that the anti-skid performance of aggregates cannot be maintained for a long time due to polishing. At the same time, the open pores on the surface are easily blocked by debris, and it is not easy to clean, and there is a problem that the noise reduction performance cannot be maintained for a long time.

Contents of the invention

The technical problem to be solved by the present invention is to provide a densely-graded road with continuous anti-slip and noise-reducing performance for the problem that the anti-slip and noise-reducing performance of asphalt concrete pavement gradually attenuates as the aggregate is polished and the pores are blocked. Asphalt concrete.

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

A densely graded asphalt concrete with continuous anti-sliding and noise reduction functions, which is prepared from coarse aggregate, fine aggregate, filler and asphalt according to the proportioning requirements of densely graded asphalt concrete, characterized in that: the coarse aggregate The material is composed of ordinary coarse aggregate and functional aggregate by volume percentage: 0-50% of ordinary coarse aggregate and 50-100% of functional aggregate, wherein the functional aggregate is a core-shell structure composed of a porous core Composed of a matrix and an alkaline surface activation shell, the porous core matrix uses mullite as the main mineral phase to form a continuous phase, and pores are distributed in the continuous phase. Mainly pores; the mineral phase composition of the alkaline surface activation shell is mainly dicalcium silicate, tricalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite.

According to the above scheme, the densely graded asphalt concrete is preferably proportioned according to AC-10, AC-13 or AC-16 densely graded asphalt concrete.

According to the above scheme, the mineral phase composition of the porous core matrix in the functional aggregate is mainly mullite, cordierite and α-quartz, and their mass percentages are: 55% to 70% of mullite, 10% of cordierite % to 15%, α-quartz 15% to 35%, and the balance is other; the mineral phase composition of the alkaline surface activation shell is mainly dicalcium silicate, tricalcium silicate, tricalcium aluminate, iron-aluminum Tetracalcium acid, its mass percentage is: dicalcium silicate 15% ~ 23%, tricalcium silicate 42% ~ 55%, tricalcium aluminate 6% ~ 15%, tetracalcium aluminoferrite 8% ~18%, the balance is other.

According to the above scheme, the functional aggregates are spherical particles with a particle size of 5-20mm, wherein the diameter of the porous core matrix is 4-15mm, and the thickness of the outer alkaline surface activation shell is 1-5mm.

According to the above scheme, the preparation method of the functional aggregate is as follows: ball mill the matrix raw material, add water, mix evenly, seal and stale, and granulate; then evenly wrap the alkaline surface activation layer powder outside the granulated matrix , obtained by secondary molding to obtain a sample wrapped with an active layer on the surface, then dried to a constant weight, then heat-preserved and fired at 1150°C to 1250°C, and then rapidly cooled;

The base raw material is composed of 20-40 parts of fly ash, 20-40 parts of kaolin, 10-16 parts of shale, 8-12 parts of talcum powder and 6-16 parts of quartz powder in parts by weight, controlled by calculation The mass percent content of each component of the mixture based on oxides is: SiO ₂ 55%-65%, Al ₂ O ₃ 18%-25%, Fe ₂ O ₃ + FeO less than 10%, CaO + MgO 4% ～6%, K ₂ O+Na ₂ O is 1.5%～4.0%, the loss on ignition is 2%～6%;

The powder of the alkaline surface activation layer is Portland cement clinker, the rate value is KH=0.8-0.96, SM=1.9-2.4, IM=1.1-1.6.

According to the above scheme, the added amount of the water is 20-30wt% of the matrix raw meal; the mass ratio of the alkaline surface activation layer powder to the matrix raw meal is 15%-20%.

According to the above scheme, the ball milling time of the matrix raw meal is 2 to 6 hours, and the particle size of the matrix raw meal after ball milling is 300 to 400 mesh; the alkaline surface activation layer powder is ground for 2-6 hours until the particle size is 300-400 mesh is obtained.

According to the above scheme, the sealing stale time is 2-3 hours; the drying temperature is 105°C-110°C.

According to the above scheme, the heat preservation firing time is 15-30min.

According to the above scheme, the rapid cooling is carried out under reducing atmosphere.

According to the above scheme, the reducing atmosphere is obtained by spraying the mixture of water and pulverized coal in a mass ratio of 1.2 to 1.5:1 onto the functional aggregates that have not yet begun to cool.

According to the above scheme, the common coarse aggregate is one or a mixture of limestone, diabase and basalt.

According to the above scheme, the fine aggregate is one or a mixture of river sand, machine-made sand or stone chips.

According to the above scheme, the filler is one or a mixture of mineral powder, lime or cement.

According to the above scheme, the asphalt is A70 heavy traffic asphalt or A90 heavy traffic asphalt or SBS I-D type modified asphalt.

According to the above scheme, the grading ratio of the densely graded asphalt concrete is to convert the volume mix ratio P _Vi obtained according to the densely graded asphalt concrete standard into the mass mix ratio _Pmi according to the following conversion formula (1):

$P_{\mathrm{mi}}=\frac{P_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}{\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\Σ}}}{P}_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}$ Formula 1)

In the formula: P _mi - the mass ratio of a certain mineral material composition /%;

P _Vi - the volume ratio of a certain mineral material composition /%;

γ _i - the relative gross volume density of a certain mineral material.

The functional aggregate used in the densely graded asphalt concrete of the present invention is porous inside, has a high sound absorption coefficient and a low elastic modulus, and can reduce noise and vibration. In addition, the surface activation layer on the surface of the functional aggregate is alkaline, which can increase the adhesion between the functional aggregate and asphalt. Compared with ordinary coarse aggregates such as basalt or limestone, the densely graded asphalt concrete prepared by doping the functional aggregates in the present invention will gradually expose tiny Pores, always maintain a surface with a large number of rough textures, and will not be polished like asphalt concrete prepared with coarse aggregates such as basalt or limestone, so that the prepared densely graded asphalt concrete has a high sound absorption coefficient and good performance. Noise reduction effect, but also has good bearing capacity and durability.

The beneficial effects of the invention are: the dense asphalt concrete provided by the invention has good bearing capacity, good water damage resistance, continuous anti-skid and noise reduction function, good durability and wide application prospects.

Description of drawings

Fig. 1 is the preparation process flowchart of functional aggregate;

Fig. 2 is the SEM test picture of functional aggregate porous core matrix;

Fig. 3 is the XRD analysis figure of porous core matrix;

Fig. 4 is an XRD analysis diagram of the outer alkaline surface activation layer shell.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

The raw materials used in the following examples are as follows:

(1) Functional aggregate: see Examples 11-13 for the preparation of functional aggregate.

(2) Asphalt: A70 heavy traffic asphalt or A90 heavy traffic asphalt or SBS I-D type modified asphalt, the quality conforms to "Technical Specifications for Construction of Highway Asphalt Pavement (JTG F40-2004)".

Table 1 Main technical indicators of asphalt

^* The test temperature is 15°C, ^** The test temperature is 5°C.

(3) Ordinary coarse aggregate: limestone or diabase or basalt, the quality conforms to "Technical Specifications for Construction of Highway Asphalt Pavement (JTGF40-2004)".

Table 2 Technical indicators of ordinary coarse aggregate

(4) Fine aggregate: river sand or machine-made sand or stone chips, the quality of which conforms to the "Technical Specifications for Construction of Highway Asphalt Pavement (JTGF40-2004)".

Table 3 Fine aggregate technical indicators

(5) Filler: mineral powder or lime or cement, the quality conforms to "Technical Specifications for Construction of Highway Asphalt Pavement (JTGF40-2004)".

Table 4 packing technical indicators

Example 1

(1) Screening of mineral materials: According to the "Technical Specifications for Construction of Highway Asphalt Pavement (JTG F40-2004)", various mineral materials are screened. The asphalt is SBS I-D modified asphalt, the functional aggregate prepared in Example 11 is used as the coarse aggregate, the fine aggregate is machine-made sand and stone chips, and the filler is mineral powder.

(2) Determination of mineral material density: According to the "Technical Specifications for Highway Asphalt Pavement Construction (JTG F40-2004)", the apparent relative density and gross volume relative density of various mineral materials are measured.

(3) Carry out mineral material gradation design according to "Technical Specifications for Highway Asphalt Pavement Construction (JTG F40-2004)", and use the resulting gradation ratio as the volume mix ratio of various mineral materials, and then according to the following formula, each The volume mix ratio (P _vi ) of the mineral material is converted into the mass mix ratio (P _mi ).

$P_{\mathrm{mi}}=\frac{P_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}{\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\Σ}}}{P}_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}$ Formula (2)

In the formula: P _mi - the mass ratio of a certain mineral material composition /%;

P _Vi - the volume ratio of a certain mineral material composition /%;

γ _i - the relative gross volume density of a certain mineral material.

(4) Combined with densely graded asphalt concrete model AC-13, the asphalt ratio is estimated to be 6.0% according to engineering experience, and then 5 points are evenly selected within the range of ±1%, namely 5.0%, 5.5%, 6.0%, and 6.5%. , 7.0%, then carry out Marshall experiment and according to "Highway Asphalt Pavement Construction Technical Specifications (JTG F40-2004)" to calculate the best asphalt ratio OAC is 6.2%; The experimental methods in JTJ 052-2000 of Mixture Test Regulations were carried out respectively for rutting test, freeze-thaw splitting test and water immersion residual stability test. The freeze-thaw splitting strength ratio and water-immersion residual stability are shown in Table 7.

(5) Using the above mineral material grading mass ratio and optimal asphalt ratio according to the "Technical Specifications for Highway Asphalt Pavement Construction (JTGF40-2004)" mixing, paving and rolling to prepare AC-13 densely graded asphalt concrete .

The above-mentioned concrete specimens were subjected to a certain number of traffic volume simulation tests, and then durability tests were carried out, including the comparison of anti-skid performance and noise reduction performance before and after use (see Table 7).

Example 2

Using the functional aggregate prepared in Example 12, the mineral aggregates were graded according to the densely graded asphalt concrete AC-10, and the rest were the same as in Example 1. The mineral aggregate volume grading ratio and the optimum asphalt ratio are shown in Table 6.

Its freeze-thaw splitting strength ratio, water immersion residual stability and durability test (including the comparison of anti-skid performance and noise reduction performance before and after use) are listed in Table 7.

Example 3

Using the functional aggregate prepared in Example 13, the mineral aggregates were graded according to the densely graded asphalt concrete AC-16, and the rest were the same as in Example 1. The mineral aggregate volume grading ratio and the optimal asphalt ratio are shown in Table 6.

Its freeze-thaw splitting strength ratio, water immersion residual stability and durability test (including the comparison of anti-skid performance and noise reduction performance before and after use) are listed in Table 7.

Table 6 AC-10, AC-13, AC-16 densely graded asphalt concrete volume ratio

^* The OGFC-13 asphalt mixture in Comparative Example 1 uses high-viscosity modified asphalt, and the AC-13 asphalt concrete in Comparative Example 2 uses SBS modified asphalt. ^** The data in brackets are the nominal particle size range of coarse aggregate.

Table 7 Performance comparison of asphalt concrete with different grades

^* Comparison of anti-skid coefficient performance with initial value after 5 years of pavement use, ^** Comparison of noise figure with initial value after 5 years of pavement use

Embodiment 4～6

Coarse aggregate is selected according to the respective volume ratios of functional aggregate and ordinary coarse aggregate in the mineral material in Table 8, and then converted according to the formula (1) in Example 1 to obtain the mineral material mass ratio, wherein: ordinary coarse aggregate The selection of aggregate and fine aggregate is carried out according to table 8, and all the other are identical with embodiment 3. Its freeze-thaw splitting strength ratio, water immersion residual stability and durability test (including the comparison of anti-slip performance and noise reduction performance before and after use) are listed in Table 9.

Table 8 Mixing ratio of AC-16 densely graded asphalt concrete with different coarse aggregate ratios

Table 9 Performance comparison of AC-16 densely graded asphalt concrete with different coarse aggregate ratios

^* Comparison of anti-skid coefficient performance with initial value after 5 years of pavement use, ^** Comparison of noise figure with initial value after 5 years of pavement use.

Combining Table 8 and Table 9, it can be obtained that the densely graded asphalt concrete prepared when the volume ratio of functional aggregate to coarse aggregate is greater than or equal to 50% can satisfy excellent water resistance and continuous anti-sliding and noise reduction performance.

Embodiment 7～8

Select asphalt according to the asphalt varieties in Table 10, and carry out aggregate gradation according to AC-16 densely graded asphalt concrete, and the rest are the same as in Example 4. Its freeze-thaw splitting strength ratio, water immersion residual stability and durability performance (including the comparison of anti-skid performance and noise reduction performance before and after use) are shown in Table 10.

Table 10 Performance comparison of AC-16 densely graded asphalt concrete with different asphalt types

^* Comparison of anti-skid coefficient performance with initial value after 5 years of pavement use, ^** Comparison of noise figure with initial value after 5 years of pavement use.

Embodiment 9～10

According to the types of fillers in Table 11, the fillers were specifically selected, and the mineral materials were graded according to the densely graded asphalt concrete AC-16, and the rest were the same as in Example 7. Its freeze-thaw splitting strength ratio, water immersion residual stability and durability performance (including the comparison of anti-skid performance and noise reduction performance before and after use) are shown in Table 11.

Table 11 Performance comparison of asphalt concrete with different fillers

^* Comparison of anti-skid coefficient performance with initial value after 5 years of pavement use, ^** Comparison of noise figure with initial value after 5 years of pavement use

Example 11-24: Preparation of functional aggregates:

Example 11

(1) Ingredients: According to Table 12, Table 13 and Table 14, the corresponding ingredients are carried out, and the chemical composition and loss on ignition LOI of the matrix raw meal thus prepared are shown in Table 15.

(2) Grinding: Put the prepared matrix raw material into a ball mill for grinding for 4 hours, control the particle size of the raw material at 325 mesh, add 22% water of the matrix raw material, mix well, seal with plastic film, and stale for 3 hours; The raw materials of the activation layer were pulverized by a ball mill for 4 hours, and the particle size was controlled at 325 mesh, and they were set aside.

(3) Molding: the stale matrix is manually molded (extrusion molding is also possible) to make a ball with a diameter of 5-15mm. Then the powder of the surface activation layer is wrapped as evenly as possible on the surface of the matrix pellet (rotary molding method can be used), and the secondary molding is carried out. The mass ratio of the powder of the surface activation layer to the matrix raw material is kept at 18%. Dry the sample after overmolding at 105°C to 110°C for 4h to constant weight.

(4) Sintering: The sintering temperature is selected at 1200°C, the holding time is 20min, and the heating rate is controlled at 5°C/min.

(5) Cooling: rapid cooling is performed under a reducing atmosphere. The reducing atmosphere is obtained by spraying the mixture of water and pulverized coal in a mass ratio of 1.2:1 onto the functional aggregates that have not yet begun to cool.

The specific preparation process is shown in Figure 1.

The prepared functional aggregate core matrix was tested by SEM, as shown in Figure 2. It can be seen from Figure 2 that the pore size of the core stomata is distributed in multiple levels, and the micron-sized pores are the main ones;

The mineral phase composition analysis of the prepared functional aggregate particles was carried out separately, and the XRD test results of the inner core matrix and the outer alkaline surface activation layer are shown in Figure 3 and Figure 4, respectively. It can be seen from Figure 3 that the core matrix of the functional aggregate is mainly composed of mullite, cordierite and α-quartz. Combined with the XRD test results, the specific mineral composition of the core matrix is: mullite 64.3%, Cordierite 13.24%, α-quartz 22.13%, and the rest are others. It can be seen from Figure 4 that the mineral phases of the outer alkaline surface activation layer of the functional aggregate are mainly dicalcium silicate, tricalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. Combined with the XRD test results, the specific mineral phase composition of the alkaline surface activation layer is: 17.34% dicalcium silicate, 47.14% tricalcium silicate, 9.17% tricalcium aluminate, 15.39% tetracalcium aluminoferrite, and The amount is other.

The linear scanning analysis of the microhardness of the matrix and shell was carried out on the prepared functional aggregates, and the thickness of the surface activation layer was measured to be 2.45mm.

See Table 14 for the particle compressive strength of the functional aggregate core matrix pellets and the specific properties of the functional aggregate.

Example 12

(1) Ingredients: According to Table 12, Table 13 and Table 14, the corresponding ingredients are carried out, and the chemical composition and loss on ignition LOI of the matrix raw meal thus prepared are shown in Table 15.

(2) Grinding: Put the prepared matrix raw material into a ball mill for grinding for 4 hours, control the particle size of the raw material at 325 mesh, add 30% water of the matrix raw material, mix well, seal with a plastic film, and stale for 2 hours; The raw materials of the first layer were pulverized by a ball mill for 4 hours, and the particle size was controlled at 325 meshes, and they were set aside.

(3) Molding: the stale matrix is manually molded (extrusion molding is also possible) to make a ball with a diameter of 5-15mm. Then the powder of the surface active layer is wrapped on the surface of the matrix pellet as evenly as possible (rotation molding can be used), and the secondary molding is carried out. The mass ratio of the powder of the surface active layer to the raw material of the matrix is kept at 15%. The sample after secondary molding was dried at 105°C to 110°C until constant weight.

(4) Sintering: The sintering temperature is selected at 1200°C, the holding time is 20min, and the heating rate is controlled at 5°C/min.

(5) Cooling: rapid cooling is performed under a reducing atmosphere. The SEM test of the prepared functional aggregate core matrix can be obtained: the pore diameter of the core is multi-level distribution, and the micron-sized pores are the main ones;

The prepared functional aggregate particles were peeled off to analyze the mineral phase composition. The XRD test results of the inner core matrix and the outer alkaline surface activation layer can be obtained: the inner core matrix of the functional aggregate is mainly composed of mullite, cordierite and α-quartz, combined with the XRD test results, it can be calculated that the specific mineral composition of the inner core matrix is: mullite 63.54%, cordierite 13.91%, α-quartz 20.16%, and the balance is other; the outer alkaline surface activation layer The mineral phases are mainly composed of dicalcium silicate, tricalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Combined with the XRD test results, the specific mineral phase composition of the alkaline surface activation layer is: 15.84% dicalcium silicate, 53.63% tricalcium silicate, 7.56% tricalcium aluminate, 14.36% tetracalcium aluminoferrite, and the remaining The amount is other. The linear scanning analysis of the microhardness of the matrix and shell was carried out on the prepared functional aggregate, and the thickness of the surface activation layer was measured to be 2.97mm.

See Table 14 for the particle compressive strength of the functional aggregate core matrix pellets and the specific properties of the functional aggregate.

Example 13

(1) Ingredients: According to Table 12, Table 13 and Table 14, the corresponding ingredients are carried out, and the chemical composition and loss on ignition LOI of the matrix raw meal thus prepared are shown in Table 15.

(2) Grinding: Put the prepared matrix raw material into a ball mill for grinding for 4 hours, control the particle size of the raw material at 325 mesh, add water and mix evenly, seal it with a plastic film, and put it stale; grind the raw material of the surface active layer with a ball mill for 4 hours , control particle size at 325 mesh, spare.

(3) Molding: the stale matrix is manually molded (extrusion molding is also possible) to make small balls. Then wrap the powder of the surface active layer on the surface of the matrix pellet as evenly as possible (rotation molding can be used), and perform secondary molding. The overmolded samples were dried to constant weight.

(4) Sintering: The sintering temperature is selected at 1200°C, and the holding time is 20min.

(5) Cooling: The cooling system is rapid cooling under reducing atmosphere. The reducing atmosphere is prepared by uniformly spraying water and pulverized coal on the uncooled functional aggregate at a mass ratio of 1.5:1.

The SEM test of the prepared functional aggregate core matrix can be obtained: the pore diameter of the core is multi-level distribution, and the micron-sized pores are the main ones;

The prepared functional aggregate particles were peeled off to analyze the mineral phase composition. The XRD test results of the inner core matrix and the outer alkaline surface activation layer can be obtained: the inner core matrix of the functional aggregate is mainly composed of mullite, cordierite and α-quartz, combined with the XRD test results, it can be calculated that the specific mineral composition of the inner core matrix is: mullite 62.68%, cordierite 12.17%, α-quartz 24.61%, and the balance is other; the outer alkaline surface activation layer The mineral phases are mainly composed of dicalcium silicate, tricalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Combined with the XRD test results, the specific mineral phase composition of the alkaline surface activation layer is: 20.57% dicalcium silicate, 44.92% tricalcium silicate, 9.17% tricalcium aluminate, 15.39% tetracalcium aluminoferrite, and the rest The amount is other. The linear scanning analysis of the microhardness of the matrix and shell was carried out on the prepared functional aggregate, and the thickness of the surface activation layer was measured to be 3.54mm.

See Table 14 for the particle compressive strength of the functional aggregate core matrix pellets and the specific properties of the functional aggregate.

Examples 14-17

Referring to the preparation method of Example 11, the corresponding ingredients were prepared according to Table 12, Table 13 and Table 14. The chemical composition and loss on ignition LOI of the matrix raw meal thus prepared are shown in Table 15. The rest of the preparation conditions were the same as in Example 11. The specific performance is shown in Table 14.

Examples 18-19

With reference to the preparation method of Example 11, set the corresponding firing temperature according to Table 16, and the rest are the same as in Example 11. The specific performance is shown in Table 16.

Example 20-21

With reference to the preparation method of Example 11, the heat preservation and firing time is set according to Table 17, and the rest are the same as in Example 11. The specific performance is shown in Table 17.

Examples 22-24

With reference to the preparation method of Example 11, set the ball milling time of the matrix raw material and the surface activation layer according to Table 8, and the rest are the same as in Example 11.

Table 12 Raw material composition of matrix and surface activation layer

The rate value of table 13 surface activation layer raw material

Table 14 Effects of changes in matrix raw meal and surface active layer components on the performance of functional aggregates

Table 15 Chemical Composition/wt.% of Base Raw Meal

Table 16 Effect of firing temperature on performance of functional aggregates

Table 17 Influence of heat preservation and firing time on the performance of functional aggregates

Table 18 The effect of the grinding time (particle size) of the base raw meal and the surface activation layer on the performance of functional aggregates

Note: The tests of apparent density, porosity, 1h water absorption and cylinder compressive strength in Table 14, 16-18 are carried out according to "Light Aggregate and Its Test Methods" GBT17431.1-2010; the adhesion with ordinary asphalt is according to "Highway Engineering asphalt and asphalt mixture test procedures JTJ 052-2000 "standard determination.

The functional aggregates prepared in Examples 14-24 can also be applied to the preparation of dense asphalt concrete of the present invention with reference to the above examples, and will not be listed here.

In addition, each specific raw material enumerated in the present invention, and the upper and lower limits and interval values of each raw material, and the upper and lower limits and interval values of process parameters (such as temperature, time, etc.) can all realize the present invention, and are no longer repeated here. A list of examples.

Claims (10)

1. dense-graded asphalt concrete with lasting antiskid decrease of noise functions, it is formulated to be selected materials according to the dense-graded asphalt concrete ratio requirement by coarse aggregate, fine aggregate, filler and pitch, it is characterized in that: described coarse aggregate by common coarse aggregate and functional aggregate by volume per-cent count: common coarse aggregate 0～50%; Functional aggregate 50～100% is formed; Wherein, described functional aggregate is a nucleocapsid structure, is made up of porous kernel matrix and basic surface activation shell; Described porous kernel matrix is that main mine forms external phase mutually with the mullite; Be distributed with pore in the external phase, described air vent aperture is multistage distribution, and is main with the micron order aperture; The ore deposit phase composite of described basic surface activation shell is mainly Dicalcium Phosphate (Feed Grade), tricalcium silicate, tricalcium aluminate, celite.

2. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 is characterized in that: said dense-graded asphalt concrete is according to AC-10, and AC-13 or AC-16 dense-graded asphalt concrete carry out proportioning.

3. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2; It is characterized in that: the ore deposit phase composite of porous kernel matrix is mainly mullite, trichroite and alpha-quartz in the said functional aggregate; Its shared mass percent is respectively: mullite 55%～70%; Trichroite 10%～15%, alpha-quartz 15%～35%, surplus is other; The ore deposit phase composite of said basic surface activation shell is mainly Dicalcium Phosphate (Feed Grade), tricalcium silicate, tricalcium aluminate, celite; Its shared mass percent is respectively: Dicalcium Phosphate (Feed Grade) 15%～23%; Tricalcium silicate 42%～55%; Tricalcium aluminate 6%～15%, celite are 8%～18%, and surplus is other.

4. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2; It is characterized in that: said functional aggregate is a spherical particle; Particle diameter is 5-20mm, and wherein the diameter of porous kernel matrix is 4～15mm, and the thickness of outside basic surface activation shell is 1～5mm.

5. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: described common coarse aggregate is one or more the mixing in ls, diabase, the Irish touchstone.

6. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: described fine aggregate is one or more the mixing in river sand, machine-processed sand or the aggregate chips.

7. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: described filler is one or more the mixing in breeze, lime or the cement.

8. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: described pitch is A70 heavy traffic paving asphalt or A90 heavy traffic paving asphalt or SBS I-D type modifying asphalt.

9. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: the level proportioning of described dense-graded asphalt concrete is the nominal mix proportion P that obtains according to the dense-graded asphalt concrete standard _ViConvert quality mixture ratio P into according to following conversion formula (1) _MiCarry out proportioning:

$P_{\mathrm{Mi}}=\frac{P_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{P}_{\mathrm{Vi}}\×{\mathrm{\γ}}_i}$ Formula (1)

In the formula: P _MiQuality mixture ratio/the % of-certain mineral aggregate composition;

P _ViNominal mix proportion/the % of-certain mineral aggregate composition;

γ _iThe corresponding gross volume specific density of-certain mineral aggregate.

10. the dense-graded asphalt concrete with lasting antiskid decrease of noise functions according to claim 1 and 2 is characterized in that: the preparation method of said functional aggregate is: with matrix raw material ball milling, add water, mix, seal old, pelletizing forming; Then basic surface active layer powder is evenly wrapped up in outside the matrix of pelletizing forming, post forming obtains wrapping up the sample of surface active layer, be dried to constant weight then after, 1150 ℃～1250 ℃ insulations are burnt till cooling fast again and are got;

Described matrix raw material are by weight by 20-40 part flyash, 20-40 part kaolin, 10-16 part shale, 8-12 part talcum powder and 6-16 part silica powder, make its mixture by the mass percentage content of each component of oxide compound be through calculation control: SiO ₂55%～65%, Al ₂O ₃18%～25%, Fe ₂O ₃+ FeO is less than 10%, and CaO+MgO is 4%～6%, K ₂O+Na ₂O is 1.5%～4.0%, and loss on ignition is 2%～6% to get;

Described basic surface active layer powder is a Portland clinker, and the rate value is KH=0.8～0.96, SM=1.9～2.4, IM=1.1～1.6.

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