Asphalt concrete pavement convenient for low-temperature construction and construction method thereof

Abstract

The present application relates to the technical field of pavement construction, and specifically discloses an asphalt concrete pavement that is easy to construct at low temperature and a construction method thereof. The asphalt concrete pavement includes a surface layer, a base layer, a subbase layer and a cushion layer from top to bottom, and the surface layer is paved with an asphalt mixture containing modified titanium gypsum; the construction method includes the following steps: S1, laying the cushion layer; S2, paving the subbase layer, the base layer and the base layer in the order of the three-layer continuous paving process, and forming a paved surface on the upper surface after rolling and curing; S3, preparing the paving surface, cleaning the paving surface, and keeping the paving surface dry; S4, preheating the paving surface; S5, a paver paving the asphalt mixture containing modified titanium gypsum to form a surface layer; S6, rolling; S7, curing. The present application has the effect of improving the water damage resistance of the asphalt concrete pavement.

Description

Technical Field

[0001] The present application relates to the field of pavement construction technology, and in particular to an asphalt concrete pavement that is easy to construct at low temperatures and a construction method thereof. Background Art

[0002] The maximum winter temperature in northern regions is usually below 10°C. In order to adapt to construction in low temperature environments, asphalt concrete pavements usually use warm-mix asphalt. Compared with hot-mix asphalt (mixing, paving and rolling temperatures are not less than 140°C), the mixing temperature of warm-mix asphalt is reduced by 20-30°C, which saves energy and reduces harmful gas emissions.

[0003] The production of warm mix asphalt mostly adopts surfactant warm mix technology. Its working principle is that the warm mix agent containing hydrophilic base and lipophilic agent forms a structural water film in the asphalt, which lubricates the asphalt, improves the fluidity of the asphalt and reduces the mixing temperature of the mixture.

[0004] However, the existence of structural water film makes the aggregate not completely dry after curing. The water in the structural water film on the aggregate surface causes water damage to the asphalt mixture, which leads to the reduction of the strength of the warm mix asphalt mixture at low temperature and the shortening of the service life of the asphalt concrete pavement. Summary of the invention

[0005] In order to improve the water damage resistance of asphalt concrete pavement, the present application provides an asphalt concrete pavement that is easy to construct at low temperatures and a construction method thereof.

[0006] In the first aspect, the present application provides an asphalt concrete pavement that is easy to construct at low temperatures and adopts the following technical scheme: an asphalt concrete pavement that is easy to construct at low temperatures comprises, from top to bottom, a surface layer, a base layer, a subbase layer and a cushion layer, wherein the surface layer is paved with an asphalt mixture containing modified titanium gypsum, and the asphalt mixture containing modified titanium gypsum comprises the following raw materials in parts by weight: 47-53 parts of warm mix asphalt; 178-200 parts of fine aggregate; 113-127 parts of mineral powder; 10-12 parts of water attracting agent; 560-720 parts of modified titanium gypsum-based coarse aggregate; the modified titanium gypsum-based coarse aggregate comprises modified titanium gypsum, slag, alkaline crushed stone and mixing water, and the weight ratio of the modified titanium gypsum, slag, alkaline crushed stone and mixing water is (5-6):1:(21-14):8.

[0007] By adopting the above technical scheme, modified titanium gypsum, slag, alkaline crushed stone, warm-mix asphalt and mineral powder are used in combination. During the preparation of the asphalt mixture containing modified titanium gypsum, the structural water film on the surface of the warm-mix asphalt improves the fluidity of the warm-mix asphalt, the modified titanium gypsum separates sulfate and calcium ions, the slag and mineral powder provide sufficient aluminum ions, and the alkaline crushed stone provides hydroxide, forming a layer of adhesive material on the surface of the alkaline crushed stone. During the maintenance and use of the asphalt mixture containing modified titanium gypsum, the water in the water film structure on the aggregate surface is blocked by the adhesive material, which facilitates the gradual evaporation of the water and reduces the probability of water damage to the asphalt mixture containing modified titanium gypsum.

[0008] The adhesive material on the surface of alkaline crushed stone improves the bonding strength between alkaline crushed stone and warm mix asphalt.

[0009] The mixing and construction temperature of warm mix asphalt is lower than that of hot mix asphalt, which reduces the probability of decomposition of modified titanium gypsum.

[0010] Optionally, the modified titanium gypsum includes titanium gypsum, slag powder and cement, and the weight ratio of the titanium gypsum, slag powder and cement is (28-30):9:6.

[0011] By adopting the above technical scheme, cement is used as an alkaline activator for the reaction between titanium gypsum and slag, and slag and cement act on titanium gypsum to improve the water resistance of titanium gypsum. During the maintenance of asphalt concrete pavement, the modified gypsum is not easily hydrolyzed and separated from the aggregate, which reduces the probability of moisture adhering to the aggregate surface and facilitates the modified gypsum to adhere to the aggregate surface.

[0012] Optionally, the preparation of the modified titanium gypsum includes the following steps: mixing titanium gypsum, slag and cement in proportion, aging, drying and calcining, and then granulating to obtain the modified titanium gypsum.

[0013] By adopting the above technical scheme, the slag is activated by adjusting the humidity, so that the slag, titanium gypsum and cement react to form a gel material; drying and calcining improve the efficiency of converting soluble compounds into insoluble compounds, reduce the activity of cement, and reduce the adverse effects of unreacted cement hydration on asphalt concrete pavement.

[0014] Optionally, the preparation of the modified titanium gypsum-based coarse aggregate includes the following steps: mixing the modified titanium gypsum, slag, alkaline crushed stone and mixing water in proportion, aging for 24 hours, sprinkling water and naturally curing for 90 days, then sieving and selecting particles with a particle size of 3 to 30 mm as modified titanium gypsum-based coarse aggregate.

[0015] By adopting the above technical solution, during the aging process, the modified titanium gypsum, slag powder, alkaline crushed stone and water fully react to form a stable modified titanium gypsum-based coarse aggregate during the watering and curing process.

[0016] Optionally, the stirring specifically includes the following steps: each stirring interval is 5 minutes, the stirring time is 20 minutes, and the continuous operation is 60 minutes to complete the stirring.

[0017] By adopting the above technical solution and intermittent stirring, the coating rate of the alkaline gravel by the reaction product of modified titanium gypsum, slag powder, alkaline gravel and water is improved.

[0018] Optionally, the water-attracting agent is fine-denier polypropylene.

[0019] By adopting the above technical solution, the fine denier polypropylene fiber guides the moisture on the aggregate surface into the pores of the asphalt concrete pavement, which facilitates the evaporation of moisture, reduces the probability of water molecule aggregation, and improves the water damage resistance of the asphalt concrete pavement.

[0020] In the second aspect, the present application provides a method for constructing an asphalt concrete pavement that is convenient for low-temperature construction, which adopts the following technical solution:

[0021] A construction method for an asphalt concrete pavement that is convenient for low-temperature construction comprises the following steps:

[0022] S1. Laying the cushion layer;

[0023] S2. Lay the base, base and base in the order of subbase, base and base using a three-layer continuous paving process, and form a paving surface on the upper surface after rolling and curing;

[0024] S3. Prepare the paving surface, clean the paving surface, and keep the paving surface dry;

[0025] S4. Preheat the paving surface. Use an ironing plate to heat the paving surface to 80-100°C.

[0026] S5, a paver spreads an asphalt mixture containing modified titanium gypsum to form a surface layer;

[0027] S6, rolling;

[0028] S7. Maintenance.

[0029] By adopting the above technical scheme, the three-layer continuous paving process improves the construction efficiency. After the paving surface is preheated, the asphalt mixture containing modified titanium gypsum is paved to evaporate excess water, thereby reducing the probability of water damage to the asphalt mixture containing modified titanium gypsum and improving the water damage resistance of the asphalt concrete pavement.

[0030] Optionally, cement slurry is spread between the layers of S2.

[0031] By adopting the above technical solution, the bonding strength between layers is improved, the asphalt concrete pavement is not easy to delaminate, and the service life of the asphalt concrete pavement is extended.

[0032] Optionally, the parameters in S6 are set as follows: the initial pressure is static pressure for 1 time, the speed is 1.5-2km / h; the repeated pressure is vibration, the vibration frequency is 35-50Hz, the amplitude is 0.3-0.8mm, the speed is 3.5-4.5km / h, 1 time; the final pressure is static pressure, the speed is 2.5-3.5km / h, not less than 2 times.

[0033] By adopting the above technical solution, the settings of initial pressure, repeated pressure and final pressure improve the density and stability of the asphalt concrete pavement structure and improve the water damage resistance of the asphalt concrete pavement.

[0034] In summary, the present application includes at least one of the following beneficial technical effects:

[0035] 1. By modifying the coarse aggregate, a layer of gel material is formed on the surface of the coarse aggregate. During the maintenance and use of the asphalt mixture pavement, water molecules are not easy to gather on the surface of the coarse aggregate, reducing the probability of water damage to the asphalt concrete pavement;

[0036] 2. Modified titanium gypsum, slag, alkaline crushed stone, warm mix asphalt and mineral powder are used together. During the preparation of asphalt mixture containing modified titanium gypsum, the structural water film on the surface of warm mix asphalt improves the fluidity of warm mix asphalt, the modified titanium gypsum separates sulfate and calcium ions, the slag and mineral powder provide sufficient aluminum ions, and the alkaline crushed stone provides hydroxide, forming a layer of adhesive material on the surface of the alkaline crushed stone. During the maintenance and use of asphalt mixture containing modified titanium gypsum, the water in the water film structure on the aggregate surface is blocked by the adhesive material, which facilitates the gradual evaporation of water and reduces the probability of water damage to the asphalt mixture containing modified titanium gypsum;

[0037] 3. Cement is used as an alkaline activator for the reaction between titanium gypsum and slag. Slag and cement act on titanium gypsum, which improves the water resistance of titanium gypsum. During the maintenance of asphalt concrete pavement, the modified gypsum is not easily separated from the aggregate after hydrolysis, which reduces the probability of water adhering to the aggregate surface and facilitates the modified gypsum to adhere to the aggregate surface;

[0038] 4. Fine-denier polypropylene is added to the asphalt mixture containing modified titanium gypsum. The fine-denier polypropylene guides liquid water to flow in the direction of low humidity through wicking action, reducing the probability of water molecule aggregation and improving the water damage resistance of asphalt concrete pavement. DETAILED DESCRIPTION

[0039] The present application is further described in detail below in conjunction with embodiments and comparative examples.

[0040] In the following examples, if no specific conditions are specified, the reaction was carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0041] Warm mix asphalt is prepared from base asphalt and Evotherm-DAT warm mix agent, with Evotherm-DAT warm mix agent accounting for 0.6%; the particle size of alkaline crushed stone is 5-30mm; the chemical components in titanium gypsum are 44.85% sulfur trioxide, 36.54% calcium oxide, 12.4% ferric oxide, 3.32% titanium oxide, 1.53% silicon dioxide, 1.0% aluminum oxide, 0.14% manganese oxide, and 0.1% magnesium oxide; the slag powder is S95 grade; the slag particle size is 3-10mm, and the activity value is 90-115; the fine aggregate is natural sand with a particle size less than 2.36mm; the mineral powder fineness is 325 mesh; the fine denier polypropylene fiber fineness is 1.8dtex, and the length is 3cm; the cement is silicate cement.

[0042] Preparation Example

[0043] Preparation Example 1

[0044] S1. 61.6 kg titanium gypsum, 19.8 g slag powder and 13.2 kg cement were mixed, the water content was adjusted to 11%, and after aging for 24 hours, it was first dried at 50 ° C for 2 hours, and then calcined at 200 ° C for 1 hour. After calcination, the particle size was ball-milled to 0.2 mm, and the water content was adjusted to 11% again, and aged for 12 hours to obtain modified titanium gypsum;

[0045] S2. Take 94 kg of the above-mentioned modified titanium gypsum, 18.8 kg of slag, 394.8 kg of alkaline crushed stone and 150.4 kg of mixing water and mix them. The interval between each stirring is 5 minutes, the stirring time is 20 minutes, the continuous operation is 60 minutes, and the aging is 24 hours. After natural curing for 90 days by sprinkling water, sieve and select the modified titanium gypsum-based coarse aggregate with a particle size of 3 to 30 mm for retention.

[0046] Preparation Example 2-Preparation Example 13

[0047] The difference from Preparation Example 1 is that the amount of each material added is different, see Table 1 for details.

[0048] Preparation Example 14

[0049] The difference from Preparation Example 2 is that no slag is added to S2.

[0050] Preparation Example 15

[0051] Mix 20kg of slag, 335kg of alkaline crushed stone and 160kg of water, with an interval of 5 minutes between each stirring and a stirring time of 20 minutes. The operation is continuous for 60 minutes, and the mixture is aged for 24 hours. After natural curing for 90 days with watering, the mixture is sieved and the modified titanium gypsum-based coarse aggregate with a particle size of 3 to 30 mm is selected for retention.

[0052] Preparation Example 16

[0053] 110kg titanium gypsum, 20kg slag, 335kg alkaline crushed stone and 160kg water were mixed and stirred, with an interval of 5 minutes between each stirring and a stirring time of 20 minutes. The continuous operation was carried out for 60 minutes, and the mixture was aged for 24 hours. After natural curing for 90 days with watering, the mixture was sieved and the modified titanium gypsum-based coarse aggregate with a particle size of 3 to 30 mm was selected for retention.

[0054] Preparation Example 17

[0055] The difference from Preparation Example 2 is that S1, 72.5 kg of titanium gypsum and 37.5 g of slag powder are mixed, the water content is adjusted to 11%, and after aging for 24 hours, it is first dried in an environment of 60°C for 2 hours, and then calcined at 900°C for 1 hour. After calcination, it is ball-milled to a particle size of 0.2 mm, and the water content is adjusted to 11% again. It is aged for 12 hours to obtain modified titanium gypsum.

[0056] Preparation Example 18

[0057] The difference from Preparation Example 2 is that: S1, 72.5 kg of titanium gypsum and 37.5 g of cement are mixed, the water content is adjusted to 11%, and after aging for 24 hours, it is first dried in an environment of 60°C for 2 hours, and then calcined at 900°C for 1 hour. After calcination, it is ball-milled to a particle size of 0.2 mm, and the water content is adjusted to 11% again. It is aged for 12 hours to obtain modified titanium gypsum.

[0058] Table 1 Raw materials for preparation examples (kg)

[0059]

[0060] Example

[0061] Example 1

[0062] S1. Laying the cushion layer;

[0063] S2. Lay the base, base and base in the order of three layers using a three-layer continuous paving process, spread cement slurry between the layers, and form a paving surface on the upper surface after rolling and curing;

[0064] S3. Prepare the paving surface, clean the paving surface, and keep the paving surface dry;

[0065] S4. Preheat the paving surface. Use an ironing plate to heat the paving surface to 80-100°C.

[0066] S5, the paver uses asphalt mixture containing modified titanium gypsum to form the surface layer, the paver discharge temperature is 120-130℃, the paving temperature is 100-110℃, the paving speed is 1-3m / min, and the screed temperature is greater than 130℃;

[0067] S6, rolling, oscillating roller follow-up rolling mode, the initial compaction is static compaction once, the speed is 1.5-2km / h; the secondary compaction is vibration, the vibration frequency is 35-50Hz, the amplitude is 0.3-0.8mm, the speed is 3.5-4.5km / h, and the compaction is once; the final compaction is static compaction, the speed is 2.5-3.5km / h, and the compaction is three times;

[0068] S7. Curing: Cover with sack or film for 7 days.

[0069] Example 2-Example 17

[0070] The difference from Example 1 is that the addition amount of each material is different, see Table 2 for details.

[0071] Embodiment 18

[0072] The difference between this embodiment and embodiment 2 is that cement slurry is not spread between layers.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] The difference between this embodiment and embodiment 2 is that: no modified titanium gypsum-based coarse aggregate is added, and 3-30 mm alkaline crushed stone is selected as the coarse aggregate.

[0076] Comparative Example 2-Comparative Example 6

[0077] The difference from Example 2 is that the modified titanium gypsum-based coarse aggregate prepared in Preparation Examples 14 to 18 are used in sequence.

[0078] Comparative Example 7

[0079] The difference between this embodiment and embodiment 2 is that no water-inducing agent is added.

[0080] Table 2 Raw materials of the embodiments and comparative examples (kg)

[0081]

[0082]

[0083] Performance testing

[0084] Test methods

[0085] 1. The water-residual stability (%) of asphalt mixture containing modified titanium gypsum was measured by the method in "T0709-2000 Marshall Stability Test for Asphalt Mixture". The test results are shown in Table 3.

[0086] 2. The freeze-thaw splitting strength ratio (%) of the asphalt mixture containing modified titanium gypsum was measured using the method in "T0729-2000 Freeze-thaw splitting strength of asphalt mixture". The test results are detailed in Table 3.

[0087] Table 3 Test results of various embodiments and comparative examples

[0088]

[0089]

[0090] In combination with Example 1, Example 2 and Example 3 and Table 2, the performance of asphalt concrete pavement against water damage is improved by adjusting the addition amount of warm mix asphalt, modified titanium gypsum-based coarse aggregate, fine aggregate, mineral powder and water attracting agent in the asphalt mixture.

[0091] Combining Example 2 and Comparative Example 1 with Table 3, it can be seen that the water immersion residual stability and freeze-thaw splitting strength ratio of the asphalt mixture are improved by modifying the coarse aggregate. The modified titanium gypsum improves the water repellency of the aggregate, and water molecules cannot gather on the surface of the aggregate, thereby improving the water damage resistance of the asphalt mixture.

[0092] In combination with Example 2, Example 4 and Example 5, the water damage resistance of the asphalt mixture is improved by adjusting the type of modified titanium gypsum-based coarse aggregate.

[0093] In combination with Example 4 to Example 7 and Table 3, the proportions of slag, crushed stone, mixing water and modified titanium gypsum in the modified titanium gypsum-based coarse aggregate are adjusted to improve the water damage resistance of the asphalt concrete pavement.

[0094] It can be seen from Example 2 and Comparative Example 2 and Table 3 that the addition of slag in the modified titanium gypsum-based coarse aggregate improves the water stability and freeze-thaw resistance of the asphalt mixture. Under the action of the ion concentration difference, the modified titanium gypsum adheres to the surface of the alkaline gravel. At this time, the slag reacts with the modified titanium gypsum under the stimulation of cement, and the generated adhesive material wraps the alkaline gravel, thereby increasing the adhesive strength between the aggregate and the warm-mix asphalt, thereby improving the water-soaked residual stability of the asphalt mixture. After water molecules enter the asphalt mixture, the modified titanium gypsum-based coarse aggregate is combined with the water-inducing agent to reduce the probability of water molecule aggregation, which facilitates water molecules to pass through the asphalt concrete pavement, reduce the moisture in the asphalt mixture, and improve the freeze-thaw splitting strength ratio.

[0095] Combining Example 2, Example 8 and Example 9 with Table 3, it can be seen that with the increase of the amount of slag added in the modified titanium gypsum-based coarse aggregate, the water-residual stability of the asphalt concrete first increases and then decreases, and the freeze-thaw splitting strength ratio first increases and then decreases. With the increase of the amount of slag added, the gel material on the surface of the alkaline crushed stone increases, and the probability of aggregate contact with water molecules decreases, but the gel material hinders the movement of the aggregate, and the uniformity of the asphalt mixture decreases.

[0096] It can be seen from Example 2 and Comparative Example 3 and Table 3 that the addition of modified titanium gypsum improves the water stability and freeze-thaw resistance of asphalt mixture. The modified titanium gypsum includes titanium gypsum, slag powder and cement, which cooperate with each other to improve the water stability and strength of the modified titanium gypsum.

[0097] Combining Example 2, Example 10 and Example 11 and Table 3, it can be seen that with the increase in the amount of modified titanium gypsum added in the modified titanium gypsum-based coarse aggregate, the water-residual stability of the asphalt concrete first increases and then decreases, and the freeze-thaw splitting strength ratio first decreases and then increases. The titanium gypsum in the modified titanium gypsum and the slag powder react initially, and the adhesive material formed improves the bonding strength between the modified titanium gypsum and the alkaline gravel. After the modified titanium gypsum is bonded to the alkaline gravel, the modified titanium gypsum and the slag further react to form an adhesive material on the surface of the alkaline gravel, thereby improving the bonding strength between the alkaline gravel and the slag.

[0098] From Example 2 and Comparative Example 4 and Table 3, it can be seen that the modification of titanium gypsum by slag and cement improves the strength and water stability of the modified titanium gypsum, thereby improving the water repellency of the aggregate surface, and further improving the water immersion residual stability and freeze-thaw splitting strength ratio of the asphalt mixture.

[0099] Combining Example 2 and Comparative Example 5 with Table 3, it can be seen that the addition of cement to the modified titanium gypsum improves the water immersion residual stability and freeze-thaw splitting strength ratio of the asphalt mixture. Cement, as an alkaline activator, stimulates the activity of slag powder and improves the water stability of the modified titanium gypsum, thereby reducing the probability of separation of the modified titanium gypsum from the aggregate and improving the water stability and freeze-thaw resistance of the asphalt mixture.

[0100] Combining Example 2, Example 12 and Example 13 and Table 3, it can be seen that with the increase in the amount of cement added in the modified titanium gypsum, the water-residual stability of the asphalt concrete first increases and then decreases, and the freeze-thaw splitting strength ratio first increases and then decreases. Part of the cement does not participate in the reaction of slag. During the curing period of the asphalt mixture, this part of the cement is hydrated and stabilized, causing the volume of the asphalt mixture to change, increasing the porosity in the asphalt mixture, and reducing the water-residual stability of the asphalt concrete.

[0101] Combining Example 2 and Comparative Example 6 with Table 3, it can be seen that the addition of slag powder in the modified titanium gypsum improves the water-residual stability and freeze-thaw splitting strength ratio of the asphalt mixture. When the modified titanium gypsum without slag powder comes into contact with slag, it can also react to form a viscose material, but the modified titanium gypsum itself has low water stability and low strength, and is easily separated from the aggregate when the asphalt mixture is rolled.

[0102] Combining Example 2, Example 14 and Example 15 with Table 3, it can be seen that with the increase in the amount of slag powder added in the modified titanium gypsum, the water-residual stability of the asphalt concrete first increases and then decreases, and the freeze-thaw splitting strength ratio first increases and then decreases. The continuous increase in the amount of slag powder added increases the consumption of titanium gypsum, reduces the amount of reaction between the modified titanium gypsum and the slag, and reduces the water stability of the asphalt mixture.

[0103] Combining Example 2 and Comparative Example 7 with Table 3, it can be seen that the addition of the water attracting agent improves the water immersion residual stability and freeze-thaw splitting strength ratio of the asphalt mixture. The water attracting agent reduces the probability of water accumulation in the asphalt mixture, thereby improving the water stability of the asphalt mixture.

[0104] Combining Example 2, Example 16 and Example 17 and Table 3, it can be seen that with the increase in the amount of water-inducing agent added, the water-residual stability of the asphalt concrete first increases and then decreases, and the freeze-thaw splitting strength ratio first increases and then decreases.

[0105] It can be seen from Example 2 and Example 18 and Table 3 that spreading cement slurry between layers improves the water immersion residual stability and freeze-thaw splitting strength ratio of the asphalt mixture.

[0106] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An asphalt concrete pavement that is easy to construct at low temperatures, characterized in that: The invention relates to a method for preparing a titanium gypsum composite material. The method comprises a surface layer, a base layer, a subbase layer and a cushion layer, wherein the surface layer is paved with an asphalt mixture containing modified titanium gypsum, and the asphalt mixture containing modified titanium gypsum comprises the following raw materials in parts by weight: 47-53 parts of warm-mix asphalt; 178-200 parts of fine aggregate; 113-127 parts of mineral powder; 10-12 parts of water attracting agent; 560-720 parts of modified titanium gypsum-based coarse aggregate; the water attracting agent is fine denier polypropylene; the modified titanium gypsum-based coarse aggregate comprises modified titanium gypsum, slag, alkaline crushed stone and mixing water, and the weight ratio of the modified titanium gypsum, slag, alkaline crushed stone and mixing water is (5-6):1:(21-14):8; the preparation of the modified titanium gypsum comprises the following steps: mixing titanium gypsum, slag powder and cement in a weight ratio of (28-30):9:6, aging, drying and calcining, and then granulating to obtain the modified titanium gypsum.

2. The asphalt concrete pavement that is convenient for low temperature construction according to claim 1 is characterized in that: The preparation of the modified titanium gypsum-based coarse aggregate includes the following steps: mixing the modified titanium gypsum, slag, alkaline crushed stone and mixing water in proportion, aging for 24 hours, sprinkling water for natural curing for 90 days, and then sieving to select particles with a particle size of 3 to 30 mm as the modified titanium gypsum-based coarse aggregate.

3. The asphalt concrete pavement that is convenient for low temperature construction according to claim 2 is characterized in that: The stirring specifically includes the following steps: each stirring interval is 5 minutes, the stirring time is 20 minutes, and the stirring is completed by continuous operation for 60 minutes.

4. A method for constructing an asphalt concrete pavement that is convenient for low-temperature construction according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Laying the cushion layer; S2. Lay the base, base and base in the order of subbase, base and base using a three-layer continuous paving process, and form a paving surface on the upper surface after rolling and curing; S3. Prepare the paving surface, clean the paving surface, and keep the paving surface dry; S4. Preheat the paving surface. Use an ironing plate to heat the paving surface to 80-100°C. S5. The paver spreads the asphalt mixture containing modified titanium gypsum to form a surface layer; S6, rolling; S7. Maintenance.

5. The method for constructing an asphalt concrete pavement that is convenient for low-temperature construction according to claim 4, characterized in that: Sprinkle cement slurry between the layers of S2.

6. According to the construction method of asphalt concrete pavement that is convenient for low-temperature construction as described in claim 4, the parameters in S6 are set as follows: the initial pressure is static pressure 1 time, the speed is 1.5-2km / h; the repeated pressure is vibration, the vibration frequency is 35-50Hz, the amplitude is 0.3-0.8mm, the speed is 3.5-4.5km / h, 1 time; the final pressure is static pressure, the speed is 2.5-3.5km / h, not less than 2 times.

Images