CN111458256A - An indoor simulation test method for the drying process of aggregates in pavement production - Google Patents

Abstract

The invention discloses an indoor simulation test method for an aggregate drying process in a pavement production link, belongs to the technical field of road engineering, and particularly relates to an indoor simulation test method for an aggregate drying process in a pavement production link. The invention aims to solve the problem that the change process of the moisture content of aggregate in the drying process cannot be accurately simulated due to the lack of an indoor simulation aggregate drying process test method at present. The method comprises the following steps of 1, determining a representative particle size; 2. testing the evaporation of water content in the aggregate heating process; 3. calculating the water evaporation in the field mixing process of the mixing station; 4. and (4) determining the laboratory test parameters. The invention is used for an indoor simulation test of the aggregate drying process in the road surface production link.

Description

An indoor simulation test method for the drying process of aggregates in pavement production

technical field

The invention belongs to the technical field of road engineering, and in particular relates to an indoor simulation test method for the drying process of aggregates in the pavement production link.

Background technique

Warm mix asphalt is a new type of asphalt mixture. Compared with traditional hot mix asphalt in the construction process of production, mixing and compaction, the temperature is lower, which can reduce harmful gas emissions, save energy and reduce asphalt aging. , extending the construction season and other advantages, so it is more and more widely used. Although warm mix asphalt has many of the above advantages, the mixing temperature of warm mix asphalt is 30°C to 40°C lower than that of hot mix asphalt, which will cause the stone to not be thoroughly dried during mixing, and the water will remain in the asphalt. Between the interface with the stone, the hidden danger of water damage performance and low temperature performance of asphalt pavement is formed, thereby increasing the sensitivity of moisture content and affecting the long-term performance of the pavement. At present, researchers have made different attempts on the temperature factors and moisture content factors that affect the water stability of warm mix asphalt mixtures, but there is a lack of indoor test methods to simulate the drying process of aggregates, and it is impossible to explore the temperature and moisture content from the interface properties. Influence on the performance of warm mix asphalt mixture.

SUMMARY OF THE INVENTION

The invention provides an indoor simulation test of the aggregate drying process in the pavement production link in order to solve the problem of lack of an indoor simulated aggregate drying process test method at present and cannot accurately simulate the change process of the aggregate moisture content in the drying process. method.

The indoor simulation test method of the aggregate drying process in the pavement production link of the present invention is carried out according to the following steps:

1. Obtain the aggregate inside the aggregate pile of the mixing station, sieve and batch according to the gradation, and obtain each grade of aggregate; measure the moisture content of each grade of aggregate to take the average value, repeat the measurement 3 to 5 times to take the average value, and determine is the initial moisture content ω ₀ of the aggregate inside the aggregate pile;

2. Carry out saturated water treatment for each grade of aggregate according to the standard saturated water test method to obtain each grade of aggregate after being completely saturated;

3. Dry the fully saturated aggregates in each grade under the conditions of oven temperature of 110°C, 130°C, 150°C and 170°C respectively, measure the moisture content every 30min, and select the specifications of the same grade aggregates in the test The same drying container;

4. Count the decreasing speed of moisture content of aggregates with different particle sizes at different temperatures, find out the aggregate grade that is greatly affected by temperature and has a fast moisture content drop, and determine the aggregate of this grade as a representative particle size set. material;

5. Weigh the mass m ₀ of the representative particle size aggregate, and preheat the oven to the actual mixing temperature required by the project;

6. Transfer the representative particle size aggregates to the oven, start the indoor simulation test, take out the aggregates every 30min and measure the quality m _i (i is 1, 2, 3...) until the quality does not change;

Denote m _i -m ₀ as Δm, denote max{m _i -m ₀ } as the mass of evaporable water m _w in the aggregate, and use formula 1 to calculate the moisture content ω _i of the aggregate at each time point;

Formula one:

7. According to the moisture content of the aggregate at each time point obtained in step 3, draw the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven;

8. Substitute the drying temperature into formula 2 to calculate the actual loss of moisture content at the drying temperature, and combine the initial moisture content ω ₀ of the aggregate to obtain the moisture content ω ₁ of the aggregate after drying;

Formula 2: Q ₁ =210000×ω[2270+1.93×80]+176400×(1-ω)(T ₂ -20);

Wherein Q ₁ is the effective heat of the drying cylinder in the outdoor intermittent stirring equipment; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature;

9. The moisture content _ω1 of the aggregate after drying is compared with the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven, and the time point T corresponding to the moisture content of the aggregate before the mixing process is obtained; that is, the indoor The heating time of the oven in the simulation test is similar to the drying effect of the outdoor mixing station.

Advantages of the present invention:

The invention can simulate the change process of moisture content in the aggregate mixing process by heating in an indoor oven, draw a curve of the moisture content of the aggregate changing with time, and at the same time propose a water evaporation calculation method in the field mixing process of the mixing station. Comparing the test results, the laboratory test parameters are obtained; it lays a foundation for the in-depth study of the influence of the water content of the stone on the warm mix mixture.

Description of drawings

Fig. 1 is the variation curve of the moisture content of aggregate with drying time under the heating condition of the oven in the embodiment;

Figure 2 is the change curve of the moisture content of the aggregate under different heating temperatures in the embodiment; wherein 1 is 165°C, and 2 is 155°C;

Figure 3 is the variation curve of water content of 0.3mm basalt at different temperatures in the embodiment; wherein 1 is 110°C, 2 is 130°C, 3 is 150°C, and 4 is 110°C;

Figure 4 is the variation curve of water content of 0.6mm basalt at different temperatures in the embodiment; wherein 1 is 110°C, 2 is 130°C, 3 is 150°C, and 4 is 110°C;

Figure 5 is the variation curve of water content of 2.36mm basalt at different temperatures in the embodiment; wherein 1 is 110°C, 2 is 130°C, 3 is 150°C, and 4 is 110°C;

Figure 6 is the variation curve of water content of 4.75mm basalt at different temperatures in the embodiment; wherein 1 is 110°C, 2 is 130°C, 3 is 150°C, and 4 is 110°C;

Figure 7 is a graph showing the relationship between the water loss per unit mass of the aggregate in the embodiment as a function of time; wherein 1 is 110°C, 2 is 130°C, 3 is 150°C, and 4 is 110°C;

Detailed ways

Embodiment 1: In this embodiment, an indoor simulation test method for the drying process of aggregates in the pavement production process is carried out according to the following steps:

1. Obtain the aggregate inside the aggregate pile of the mixing station, sieve and batch according to the gradation, and obtain each grade of aggregate; measure the moisture content of each grade of aggregate to take the average value, repeat the measurement 3 to 5 times to take the average value, and determine is the initial moisture content ω ₀ of the aggregate inside the aggregate pile;

2. Carry out saturated water treatment for each grade of aggregate according to the standard saturated water test method to obtain each grade of aggregate after being completely saturated;

3. Dry the fully saturated aggregates in each grade under the conditions of oven temperature of 110°C, 130°C, 150°C and 170°C respectively, measure the moisture content every 30min, and select the specifications of the same grade aggregates in the test The same drying container;

4. Count the decreasing speed of moisture content of aggregates with different particle sizes at different temperatures, find out the aggregate grade that is greatly affected by temperature and has a fast moisture content drop, and determine the aggregate of this grade as a representative particle size set. material;

5. Weigh the mass m ₀ of the representative particle size aggregate, and preheat the oven to the actual mixing temperature required by the project;

6. Transfer the representative particle size aggregates to the oven, start the indoor simulation test, take out the aggregates every 30min and measure the quality m _i (i is 1, 2, 3...) until the quality does not change;

Denote m _i -m ₀ as Δm, denote max{m _i -m ₀ } as the mass of evaporable water m _w in the aggregate, and use formula 1 to calculate the moisture content ω _i of the aggregate at each time point;

Formula one:

7. According to the moisture content of the aggregate at each time point obtained in step 3, draw the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven;

8. Substitute the drying temperature into formula 2 to calculate the actual loss of moisture content at the drying temperature, and combine the initial moisture content ω ₀ of the aggregate to obtain the moisture content ω ₁ of the aggregate after drying;

Formula 2: Q ₁ =210000×ω[2270+1.93×80]+176400×(1-ω)(T ₂ -20);

Wherein Q ₁ is the effective heat of the drying cylinder in the outdoor intermittent stirring equipment; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature;

9. The moisture content _ω1 of the aggregate after drying is compared with the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven, and the time point T corresponding to the moisture content of the aggregate before the mixing process is obtained; that is, the indoor The heating time of the oven in the simulation test is similar to the drying effect of the outdoor mixing station.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that each grade of aggregate described in step 1 is divided into coarse grade aggregate and fine grade aggregate. Others are the same as the first embodiment.

Embodiment 3: This embodiment differs from Embodiment 1 or 2 in that: as described in step 2, each grade of aggregate is subjected to saturated water treatment according to the standard saturated water test method; Saturated with water for 0.5h under vacuum conditions of 97.3-98.7kPa, dry the surface water for use; fine-grade aggregates (2.36-0.15) were saturated with water for 12h under normal temperature and pressure conditions, and passed through filter paper (pore size: 80-120μm) 0.5h filter dry for use. Others are the same as in the first or second embodiment.

Embodiment 4: This embodiment is different from one of Embodiments 1 to 3 in that: Formula 2 in Step 8 is obtained from Formula 3;

Formula 3: Q ₁ =Q _1-1 +Q _1-2 +Q _1-3 ; where Q _1-1 is the heat required in the preheating process of the aggregate, which is ignored; Q _1-2 is the heat required for water evaporation ; Q _1-3 is the heat required for aggregate drying;

The heat Q _1-2 required for the evaporation of the water is calculated according to formula four:

其中γ为汽化热，单位为kJ/kg，取2270；C₂为水蒸汽比热，单位为kJ/kg.℃，取1.94；

为水分经过预热过程、蒸发后的温度，取100℃；T₁为水分蒸发温度，取20℃；V为烘干筒的设计生产能力，取210t/h；Formula four:

Where γ is the heat of vaporization, the unit is kJ/kg, take 2270; C ₂ is the specific heat of water vapor, the unit is kJ/kg.℃, take 1.94;

is the temperature of moisture after preheating and evaporation, which is ₁₀₀ °C; T1 is the evaporation temperature of water, which is 20°C; V is the designed production capacity of the drying cylinder, which is 210t/h;

The heat Q _1-3 required for the drying of the aggregate is calculated according to formula five:

Formula 5: Q _1-3 =1000VC _g (1-ω)(T ₂ -T ₁ ); where V is the designed production capacity of the drying cylinder, taking 210t/h; C _g is the specific heat of stone, in kJ/ kg, take 0.84; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature; T ₁ is the water evaporation temperature, taking 20°C;

Combining formula 3, formula 4 and formula 5, we get:

Others are the same as one of Embodiments 1 to 3.

Embodiment 5: This embodiment differs from one of Embodiments 1 to 4 in that: the value of Q ₁ in the formula 2 in step 8 is calculated by Q=Q ₁ +Q ₂ ; wherein Q is the consumption of the drying cylinder Total heat; _Q2 is the total heat loss;

The total heat loss _Q2 is calculated according to formula VI:

Formula 6: Q ₂ =Q _2-1 +Q _2-2 ; wherein Q _2-1 is the heat dissipation of the drying cylinder wall; Q _2-2 is the heat loss of the exhaust gas;

The heat dissipation Q _2-1 of the drying cylinder wall is calculated according to formula seven:

Formula 7: Q _2-1 =3600πDL(t _δ -t ₀ )h; where t _δ is the temperature of the cylinder wall, which is 250°C; t ₀ is the air temperature, which is 20°C;

D is the diameter of the drum, the unit is m; L is the length of the drum, the unit is m; h is the thermal conductivity of the drum wall, the unit is kJ/m ² .℃;

where h is calculated according to formula 8:

Formula eight:

Taking the exhaust gas emission as 1500m ³ /min and the specific gravity as 1.29kg/m ³ , the exhaust gas heat loss Q _2-2 is calculated according to formula 9:

Formula 9: Q _2-2 =cm(t ₂ -t ₀ ); where c is the specific heat of air, taken as 0.709kJ/kg.℃; m is the air mass, in kg; t ₂ is the exhaust gas temperature, taken as 180℃ ; t ₀ is the air temperature, take 20°C;

Taking diesel oil as combustion raw material, the density is 0.84～0.86kg/L; the total heat consumption Q of the drying cylinder is calculated according to formula ten:

Formula 10: Q=qm; where q is the combustion value, which is 4.7×10 ⁴ kJ/kg; m is the mass of combustion raw materials, the unit is kg;

Q ₁ is calculated from the above formula. Others are the same as one of Embodiments 1 to 4.

The beneficial effects of the present invention are verified by the following examples:

Embodiment 1: An indoor simulation test method for the drying process of aggregates in the pavement production process is carried out according to the following steps:

1. Obtain the aggregate inside the aggregate pile of the mixing station, sieve and batch according to the gradation, and obtain each grade of aggregate; measure the moisture content of each grade of aggregate to take the average value, repeat the measurement 3 to 5 times to take the average value, and determine is the initial moisture content ω ₀ of the aggregate inside the aggregate pile; the initial moisture content ω ₀ of the aggregate inside the aggregate pile is 5% to 6%;

2. Carry out water-saturated treatment for each grade of aggregate according to the standard saturated water test method to obtain each grade of aggregate after complete water saturation; coarse grade aggregate (19.0～4.75) is saturated with water for 0.5h under the vacuum condition of 97.3～98.7kPa , dry the surface water for use; fine-grade aggregates (2.36-0.15) are saturated with water for 12h under normal temperature and pressure conditions, and are filtered through filter paper (pore size is 80-120μm) for 0.5h;

3. Dry the fully saturated aggregates in each grade under the conditions of oven temperature of 110°C, 130°C, 150°C and 170°C respectively, measure the moisture content every 30min, and select the specifications of the same grade aggregates in the test The same drying container;

4. Statistics on the decreasing rate of moisture content of aggregates with different particle sizes at different temperatures, see Table 2. The decreasing rate of moisture content of 0.3mm stone is relatively large, and it is most affected by drying temperature. The aggregate of 0.3mm specification is determined as the representative particle size aggregate;

5. Weigh the mass m ₀ of the representative particle size aggregate, and preheat the oven to the actual mixing temperature required by the project; in this embodiment, two warm mix asphalt mixtures, Sasobit and AM6505, are selected as the research objects, and the Sasobit warm mix mixture is determined. The aggregate mixing temperature is 155°C, and the AM6505 warm mix asphalt mixing temperature is 165°C;

6. Transfer the representative particle size aggregates to the oven, start the indoor simulation test, take out the aggregates every 30min and measure the quality m _i (i is 1, 2, 3...) until the quality does not change;

Denote m _i -m ₀ as Δm, denote max{m _i -m ₀ } as the mass of evaporable water m _w in the aggregate, and use formula 1 to calculate the moisture content ω _i of the aggregate at each time point;

Formula one:

7. According to the moisture content of the aggregate at each time point obtained in step 3, draw the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven; as shown in Figure 1;

8. Substitute the drying temperature into formula 2 to calculate the actual loss of moisture content at the drying temperature, and the drying capacity of the aggregate moisture content in the mixing building can be obtained (see Table 1). Combined with the initial moisture content of the aggregate of 5-6%, The moisture content _ω1 of the obtained aggregate after drying is 1-2%;

Formula 2: Q ₁ =210000×ω[2270+1.93×80]+176400×(1-ω)(T ₂ -20);

Wherein Q ₁ is the effective heat of the drying cylinder in the outdoor intermittent stirring equipment; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature;

9. The moisture content _ω1 of the aggregate after drying is compared with the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven. It can be seen that the moisture content of the aggregate after heating for 1h is about 1.4%, which is consistent with the above obtained It is close to the moisture content of the aggregate before the mixing process of 1.0% to 2.0%, so the heating time of the indoor test oven can be 1h; that is, the heating time of the oven is similar to the drying effect of the indoor simulation test and the outdoor mixing station;

The value of Q ₁ in the formula 2 of step 8 is calculated by Q=Q ₁ +Q ₂ ; wherein Q is the total heat consumption of the drying cylinder; Q ₂ is the total heat loss;

The total heat loss _Q2 is calculated according to formula VI:

Formula 6: Q ₂ =Q _2-1 +Q _2-2 ; wherein Q _2-1 is the heat dissipation of the drying cylinder wall; Q _2-2 is the heat loss of the exhaust gas;

The heat dissipation Q _2-1 of the drying cylinder wall is calculated according to formula seven:

Formula 7: Q _2-1 =3600πDL(t _δ -t ₀ )h; where t _δ is the temperature of the cylinder wall, which is 250°C; t ₀ is the air temperature, which is 20°C;

D is the diameter of the drum, the unit is m; L is the length of the drum, the unit is m; h is the thermal conductivity of the drum wall, the unit is kJ/m ² .℃;

where h is calculated according to formula 8:

Formula eight:

Taking the exhaust gas emission as 1500m ³ /min and the specific gravity as 1.29kg/m ³ , the exhaust gas heat loss Q _2-2 is calculated according to formula 9:

Formula 9: Q _2-2 =cm(t ₂ -t ₀ ); where c is the specific heat of air, taken as 0.709kJ/kg.℃; m is the air mass, in kg; t ₂ is the exhaust gas temperature, taken as 180℃ ; t ₀ is the air temperature, take 20°C;

Taking diesel oil as combustion raw material, the density is 0.84～0.86kg/L; the total heat consumption Q of the drying cylinder is calculated according to formula ten:

Formula 10: Q=qm; where q is the combustion value, which is 4.7×10 ⁴ kJ/kg; m is the mass of combustion raw materials, the unit is kg;

Q ₁ is calculated from the above formula.

Table 1 Drying capacity of aggregate moisture content of 1000 type mixing building

parameter Sasobit AM6505 Aggregate temperature 155 165 Aggregate moisture content drying capacity (%) 4.2 4.3

Table 2 The decreasing rate of moisture content of aggregates with different particle sizes at different temperatures

0.075mm 0.15mm 0.3mm 0.6mm 1.18mm 2.36mm 4.75mm 9.5mm 13.2mm 26.5mm 110℃ 0.093 0.081 0.072 0.057 0.030 0.004 0.001 0.00063 0.00052 0.00041 130℃ 0.091 0.083 0.084 0.062 0.035 0.005 0.002 0.0006 0.0006 0.0006 150℃ 0.112 0.133 0.108 0.098 0.066 0.008 0.003 0.0013 0.0012 0.0010 170℃ 0.139 0.130 0.151 0.096 0.053 0.009 0.003 0.0013 0.0014 0.0013

Fig. 1 is the variation curve of aggregate moisture content with drying time under oven heating conditions in the embodiment; Fig. 2 is the variation curve of aggregate moisture content under different heating temperatures in the embodiment; Fig. 3 is the variation curve of 0.3mm basalt in the embodiment The change curve of water content under temperature; Fig. 4 is the change curve of water content under different temperatures of 0.6mm basalt in the embodiment; Fig. 5 is the change curve of water content under different temperature of 2.36mm basalt in the embodiment; Fig. 6 is in the embodiment Variation curve of moisture content of 4.75mm basalt at different temperatures; Fig. 7 is the relationship diagram of the water loss per unit mass of aggregate at different temperatures in the embodiment as a function of time. Analysis of the moisture content of 0.3mm aggregate at different temperatures with drying The law of time change, the water loss per unit mass of aggregate (/0.5h) is defined as the ratio of the mass of water lost by the aggregate to the mass of the aggregate per half hour, and the water loss per unit mass of the aggregate at different temperatures is plotted. The relationship diagram of time change; it can be seen from the figure that with the increase of drying temperature, the stable time area gradually shortens. During drying at 110℃ for 1-4h, the water loss per unit mass of the stone remains basically stable, while at 170℃, there is no stable time zone. For the stone with lower drying temperature, the water loss per unit mass of the stone has a longer stable time area, indicating that at this drying temperature, the drying time is particularly important for this kind of stone, which directly affects the moisture content of the stone.

Claims (5)

1. the indoor simulation test method of a pavement production link aggregate drying process, it is characterized in that the indoor simulation test method of the pavement production link aggregate drying process is to carry out according to the following steps: 1. Obtain the aggregate inside the aggregate pile of the mixing station, sieve and batch according to the gradation, and obtain each grade of aggregate; measure the moisture content of each grade of aggregate to take the average value, repeat the measurement 3 to 5 times to take the average value, and determine is the initial moisture content ω ₀ of the aggregate inside the aggregate pile; 2. Carry out saturated water treatment for each grade of aggregate according to the standard saturated water test method to obtain each grade of aggregate after being completely saturated; 3. Dry the fully saturated aggregates in each grade under the conditions of oven temperature of 110°C, 130°C, 150°C and 170°C respectively, measure the moisture content every 30min, and select the specifications of the same grade aggregates in the test The same drying container; 4. Count the decreasing speed of moisture content of aggregates with different particle sizes at different temperatures, find out the aggregate grade that is greatly affected by temperature and has a fast moisture content drop, and determine the aggregate of this grade as a representative particle size set. material; 5. Weigh the mass m ₀ of the representative particle size aggregate, and preheat the oven to the actual mixing temperature required by the project; 6. Transfer the representative particle size aggregates to the oven, start the indoor simulation test, take out the aggregates every 30min and measure the quality m _i (i is 1, 2, 3...) until the quality does not change; Denote m _i -m ₀ as Δm, denote max{m _i -m ₀ } as the mass of evaporable water m _w in the aggregate, and use formula 1 to calculate the moisture content ω _i of the aggregate at each time point; Formula one:

7. According to the moisture content of the aggregate at each time point obtained in step 3, draw the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven; 8. Substitute the drying temperature into formula 2 to calculate the actual loss of moisture content at the drying temperature, and combine the initial moisture content ω ₀ of the aggregate to obtain the moisture content ω ₁ of the aggregate after drying; Formula 2: Q ₁ =210000×ω[2270+1.93×80]+176400×(1-ω)(T ₂ -20); Wherein Q ₁ is the effective heat of the drying cylinder in the outdoor intermittent stirring equipment; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature; 9. The moisture content _ω1 of the aggregate after drying is compared with the change curve of the moisture content of the aggregate with the drying time under the heating condition of the oven, and the time point T corresponding to the moisture content of the aggregate before the mixing process is obtained; that is, the indoor The heating time of the oven in the simulation test is similar to the drying effect of the outdoor mixing station. 2 . The indoor simulation test method for the drying process of aggregates in a pavement production link according to claim 1 , wherein the aggregates described in step 1 are divided into coarse aggregates and fine aggregates. 3 . 3. the indoor simulation test method of a kind of pavement production link aggregate drying process according to claim 2, is characterized in that according to the standard saturated water test method described in step 2, carries out saturated water treatment to each grade of aggregate; wherein Coarse aggregates (19.0-4.75) were saturated with water for 0.5h under vacuum conditions of 97.3-98.7kPa, and the surface water was wiped dry for use; fine aggregates (2.36-0.15) were saturated with water for 12h under normal temperature and pressure, and passed Filter paper (with a pore size of 80-120 μm) was filtered and dried for 0.5 h for later use. 4. the indoor simulation test method of a kind of pavement production link aggregate drying process according to claim 1, is characterized in that in step 8, formula two is obtained by formula three; Formula 3: Q ₁ =Q _1-1 +Q _1-2 +Q _1-3 ; where Q _1-1 is the heat required in the preheating process of the aggregate, which is ignored; Q _1-2 is the heat required for water evaporation ; Q _1-3 is the heat required for aggregate drying; The heat Q _1-2 required for the evaporation of the water is calculated according to formula four: Formula four:

Wherein γ is the heat of vaporization, the unit is kJ/kg, take 2270; C ₂ is the specific heat of water vapor, the unit is kJ/kg.℃, take 1.94;

is the temperature of moisture after preheating and evaporation, which is ₁₀₀ °C; T1 is the evaporation temperature of water, which is 20°C; V is the designed production capacity of the drying cylinder, which is 210t/h; The heat Q _1-3 required for the drying of the aggregate is calculated according to formula five: Formula 5: Q _1-3 =1000VC _g (1-ω)(T ₂ -T ₁ ); where V is the designed production capacity of the drying cylinder, taking 210t/h; C _g is the specific heat of stone, in kJ/ kg, take 0.84; T ₂ is the drying temperature; ω is the actual loss of moisture content at the drying temperature; T ₁ is the water evaporation temperature, taking 20°C; Combining formula 3, formula 4 and formula 5, we get:

5. the indoor simulation test method of a kind of pavement production link aggregate drying process according to claim 1, is characterized in that the value of Q ₁ in the formula two described in step 8 is calculated by Q=Q ₁ +Q ₂ ; Wherein Q is the total heat consumption of the drying cylinder; _Q2 is the total heat loss; The total heat loss _Q2 is calculated according to formula VI: Formula 6: Q ₂ =Q _2-1 +Q _2-2 ; wherein Q _2-1 is the heat dissipation of the drying cylinder wall; Q _2-2 is the heat loss of the exhaust gas; The heat dissipation Q _2-1 of the drying cylinder wall is calculated according to formula seven: Formula 7: Q _2-1 =3600πDL(t _δ -t ₀ )h; where t _δ is the temperature of the cylinder wall, which is 250°C; t ₀ is the air temperature, which is 20°C; D is the diameter of the drum, the unit is m; L is the length of the drum, the unit is m; h is the thermal conductivity of the drum wall, the unit is kJ/m ² .℃; where h is calculated according to formula 8: Formula eight:

Taking the exhaust gas emission as 1500m ³ /min and the specific gravity as 1.29kg/m ³ , the exhaust gas heat loss Q _2-2 is calculated according to formula 9: Formula 9: Q _2-2 =cm(t ₂ -t ₀ ); where c is the specific heat of air, taken as 0.709kJ/kg.℃; m is the air mass, in kg; t ₂ is the exhaust gas temperature, taken as 180℃ ; t ₀ is the air temperature, take 20°C; Taking diesel oil as combustion raw material, the density is 0.84～0.86kg/L; the total heat consumption Q of the drying cylinder is calculated according to formula ten: Formula 10: Q=qm; where q is the combustion value, which is 4.7×10 ⁴ kJ/kg; m is the mass of combustion raw materials, the unit is kg; Q ₁ is calculated from the above formula.

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