Light-color aggregate porous pavement paving structure

Abstract

The utility model provides a light aggregate porous pavement paving structure which comprises an isolating layer, a graded broken stone subbase layer, an open graded asphalt stabilized broken stone base layer, a porous asphalt concrete lower surface layer and a porous asphalt concrete upper surface layer from bottom to top, and the brightness of aggregate in the porous asphalt concrete upper surface layer is 50-100. According to the light-color aggregate porous pavement paving structure, the solar radiation absorption rate of the pavement can be reduced, so that the heat accumulation is reduced, and the temperature of a pavement structure layer is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of road paving, in particular to a light-colored aggregate porous road paving structure. Background Art

[0002] As a common type of pavement for urban roads and highways, dense-graded asphalt pavement has been widely used due to its significant advantages such as high flatness, low noise, strong wear resistance and strong bearing capacity. However, since the asphalt and aggregates used in dense-graded asphalt pavement are both black-colored materials, the pavement solar reflectivity is between 5% and 15%, which means that the pavement will absorb 85% to 95% of solar radiation; in addition, since this type of pavement belongs to a suspended dense structure, the proportion of fine aggregates is relatively large, with a small porosity, the contact between aggregates is more sufficient, the efficiency of heat conduction is higher, and the convective heat exchange effect of the air in the structural layer is greatly limited, so the heat inside the pavement will be difficult to dissipate, which leads to an increase in the temperature of the pavement structure layer, which in turn causes high-temperature rutting disease, further exacerbating the urban heat island effect. Utility Model Content

[0003] In order to solve the problems existing in the prior art, the utility model provides a light-colored aggregate porous road paving structure, which can reduce the road surface's absorption rate of solar radiation, thereby reducing heat accumulation and helping to reduce the temperature of the road surface structure layer.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a light-colored aggregate porous road pavement structure, which includes, from bottom to top, an isolation layer, a graded crushed stone subbase, an open-graded asphalt stabilized crushed stone base, a porous asphalt concrete lower layer and a porous asphalt concrete upper layer, wherein the lightness of the aggregate in the porous asphalt concrete upper layer is 50-100.

[0005] Furthermore, the porous asphalt concrete upper layer adopts a PAC-13 grading design, has a thickness of 2 cm-4 cm, and a void ratio of 18%-25%.

[0006] Furthermore, the aggregates are natural diabase and limestone.

[0007] Further, limestone is used for particle size of 0-3 mm, and diabase aggregate is used for other particle sizes.

[0008] Furthermore, the upper layer of porous asphalt concrete also includes high-viscosity modified asphalt.

[0009] Furthermore, the dynamic viscosity of the high-viscosity modified asphalt at 60°C is ≥20,000 Pa·s.

[0010] Furthermore, the porous asphalt concrete lower layer adopts a PAC-20 grading design, has a thickness of 4 cm-6 cm, and a void ratio between 18% and 25%.

[0011] Furthermore, the open-graded asphalt stabilized macadam base layer adopts an ATPB-25 gradation design, with a thickness of 30cm-36cm and a void ratio between 20% and 25%.

[0012] Furthermore, the thickness of the graded crushed stone base layer is 25 cm to 30 cm, and the void ratio is not less than 14%.

[0013] Furthermore, the isolation layer includes natural sand and permeable geotextile. The natural sand is laid on the roadbed structure with a thickness of 5 cm to 10 cm, and the permeable geotextile covers the natural sand.

[0014] Compared with the prior art, the utility model has at least the following beneficial effects:

[0015] The utility model proposes a light-colored aggregate porous pavement paving structure, which uses light-colored aggregate with a brightness greater than 50-100 and applies it to the porous asphalt concrete upper layer of the porous asphalt pavement, reducing the road's absorption rate of solar radiation, thereby reducing heat accumulation, helping to reduce the temperature of the pavement structure layer, and providing a powerful solution to the problem of urban heat island effect; in addition to the advantage of high reflectivity, the porous structure of the porous pavement paving structure of the utility model also plays a key role in heat transfer, and the gaps in the porous structure allow air to flow and exchange heat with the pavement material. This design greatly reduces the heat conduction from top to bottom of the pavement, further enhancing its heat dissipation performance. Under high temperature conditions in summer, the pavement temperature of the utility model is 6.7°C lower than that of ordinary asphalt pavement, and the cooling effect is significant.

[0016] The aggregates of the upper layer of porous asphalt concrete of the utility model are natural diabase and limestone with a lightness of 50-100, and limestone is used for the particle size of 0-3mm, and diabase aggregate is used for other particle sizes. This setting can not only extend the service life of the road, reduce the road maintenance work caused by high temperature rutting disease, but also reduce the carbon emissions generated by road maintenance. This design concept is consistent with the low-carbon and environmental protection concept currently advocated by the world, and is expected to become a new trend in future urban road construction.

[0017] In summary, the light-colored aggregate porous pavement exhibits an excellent cooling effect due to its unique reflective properties and porous structure. It significantly reduces the radiant heat absorbed by the pavement and effectively blocks the heat conduction from top to bottom. This not only helps reduce the occurrence of high-temperature pavement diseases, but also helps alleviate the urban heat island effect, making a positive contribution to the improvement of the urban environment and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of the pavement structure of the utility model.

[0019] Figure 2 It is a schematic cross-sectional diagram of the pavement structure of the utility model.

[0020] In the figure: 1—porous asphalt concrete upper layer; 2—porous asphalt concrete lower layer; 3—open-graded asphalt stabilized gravel base layer; 4—graded gravel subbase layer; 5—isolation layer. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings, but the following embodiments are only used to help understand the principle and core idea of ​​the present invention, and are not intended to limit the scope of protection of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, improvements made to the present invention also fall within the scope of protection of the claims of the present invention.

[0022] See also Figure 1 , Figure 2 The utility model provides a light-colored aggregate porous road paving structure. This structure utilizes natural light-colored aggregate and applies it to porous asphalt pavement, which reduces the road's absorption rate of solar radiation, thereby reducing heat accumulation and helping to reduce the temperature of the pavement structure layer. Specifically, from bottom to top, it includes an isolation layer 5, a graded crushed stone subbase 4, an open-graded asphalt stabilized crushed stone base 3, a porous asphalt concrete lower layer 2 and a porous asphalt concrete upper layer 1.

[0023] Preferably, the porous asphalt concrete top layer 1 adopts a PAC-13 grading design with a thickness of 2cm-4cm; the material uses light-colored aggregate, using natural diabase and limestone with low lightness value and white chroma, and its lightness L value is 50-100.

[0024] Preferably, the porous asphalt concrete lower layer 2 adopts a PAC-20 grading design with a thickness of 4 cm-6 cm;

[0025] Preferably, the porosity of the porous asphalt concrete upper layer 1 and the porous asphalt concrete lower layer 2 is between 18% and 25%.

[0026] Preferably, the open-graded asphalt-stabilized macadam base layer 3 adopts an ATPB-25 grading design, has a thickness of 30 cm-36 cm, and a void ratio of 20%-25%.

[0027] Preferably, the graded crushed stone base layer 4 has a thickness of 25 cm to 30 cm and a porosity of not less than 14%.

[0028] Preferably, the isolation layer 5 is located at the bottom of the pavement structure, with the roadbed structure below it. The layer is composed of natural sand and permeable geotextile. The thickness of the natural sand is 5 cm to 10 cm, and the top surface of the natural sand is covered with permeable geotextile. Its function is to improve the bearing capacity of the foundation, reduce the settlement, and play the role of isolation, filtration, drainage, and reinforcement.

[0029] Compared with common porous permeable pavements, the light-colored aggregate porous pavement paving structure of the utility model shows more outstanding performance. First of all, because it uses natural light-colored aggregates, this pavement has a higher solar reflectivity. This means that it can effectively reduce the absorption of solar radiation and reduce the heat accumulation of the pavement. This feature makes the light-colored aggregate porous pavement effective in reducing heat sources, providing a powerful solution to the problem of urban heat island effect. In addition to the advantage of high reflectivity, this porous structure also plays a key role in heat transfer. The gaps in the porous structure allow air to flow and exchange heat with the pavement material. This design greatly reduces the heat conduction from top to bottom of the pavement, further enhancing its heat dissipation performance. Under high temperature conditions in summer, the temperature of the pavement of the utility model is 6.7°C lower than that of ordinary asphalt pavement, and the cooling effect is significant.

[0030] Example:

[0031] The utility model discloses a light-colored aggregate porous road pavement structure, wherein:

[0032] 1. The porous asphalt concrete upper layer 1 adopts PAC-13 grading design, with a thickness of 4 cm and a void ratio of 20.4%;

[0033] The porous asphalt concrete upper layer 1 uses materials including high-viscosity modified asphalt, light-colored aggregate, lignin fiber, mineral powder, etc., and its performance indicators meet the requirements of relevant specifications; according to the "Technical Specifications for Highway Asphalt Pavement Construction", the PAC-13 light-colored aggregate ratio of the porous asphalt concrete upper layer 1 is determined: the sieve pass rate of each level is 16mm is 100%; 13.2mm is 90.5% (90%~100%); 9.5mm is 59.7% (40% to 71%); 4.75mm is 14.7% (10% to 30%); 2.36mm is 10.8% (9% to 20%); 1.18mm is 9.4% (7% to 17%); 0.6mm is 7.3% (6% to 14%); 0.3mm is 5.7% (5% to 12%); 0.15mm is 5.4% (4% to 9%); 0.075mm is 5.0% (3% to 6%). The brackets are the range of passing rates for each grade required by the specification. In addition, mineral powder 4%; optimal asphalt dosage 5.2%; fiber dosage 0.3%.

[0034] Light-colored aggregates include light-colored limestone aggregates and light-colored diabase aggregates. The lightness L value of 0-3mm light-colored limestone aggregates is 59.02, and the color difference △ELab with conventional aggregates can reach 7.95, with high solar reflectivity. Other particle sizes use light-colored diabase aggregates, whose lightness L value is 62.75, and the color difference △ELab with conventional aggregates is as high as 13.98.

[0035] Preferably, the dynamic viscosity of the high-viscosity modified asphalt at 60°C is ≥ 20,000 Pa·s.

[0036] 2. The porous asphalt concrete lower layer 2 adopts a PAC-20 gradation design with a thickness of 6 cm and a void ratio of 20.8%.

[0037] 3. The open-graded asphalt stabilized macadam base 3 adopts an ATPB-25 gradation design with a thickness of 36 cm and a void ratio of 21.3%.

[0038] 4. The graded crushed stone base layer 4 has a thickness of 30 cm and a void ratio of 17.8%.

[0039] 5. The thickness of natural sand in the isolation layer 5 is 5 cm, and a permeable geotextile is laid on top.

[0040] When the light-colored aggregate porous pavement paving structure of the utility model is used, the porous asphalt concrete upper layer 1 is paved with light-colored aggregate. Under the action of vehicle wear, the light-colored aggregate is exposed, and its high solar reflectivity greatly reduces the radiant heat absorbed by the road surface. In addition, when the surface layer porosity is about 20%, the heat dissipation capacity of the road surface is greatly improved. Under the action of the wheel suction pump, the air flow capacity in the gap is stronger, which accelerates the heat exchange between the road surface and the air, and effectively reduces the road surface temperature. On the porous road surface, rainwater infiltrates into the base material (including the open-graded asphalt stabilized macadam base 3 and the graded macadam subbase 4), and the base material discharges the rainwater into the roadbed. Through the filtering and purification of the large-particle-size macadam material, the rainwater is effectively stored and utilized, and heat exchange is achieved in this process. In addition, the surface layer structure using PAC-13 and PAC-20 can effectively prevent the infiltration of large-particle-size impurities, which affects the water permeability and cooling effect. The surface layer asphalt material uses high-viscosity modified asphalt to prevent the light-colored aggregate from falling off and improve the overall strength of the road surface.

[0041] In summary, the light-colored aggregate porous pavement structure not only achieves the cooling function in actual use, but also has the functions of water permeability and environmental protection. This pavement structure provides new possibilities for urban construction and sustainable development.

Claims

1. A light-colored aggregate porous road pavement structure, characterized in that: From bottom to top, it includes an isolation layer (5), a graded crushed stone base layer (4), an open-graded asphalt stabilized crushed stone base layer (3), a porous asphalt concrete lower layer (2) and a porous asphalt concrete upper layer (1), wherein the lightness of the aggregate in the porous asphalt concrete upper layer (1) is 50-100; The porous asphalt concrete top layer (1) is designed with PAC-13 grading, with a thickness of 2 cm-4 cm and a void ratio of 18%-25%; The porous asphalt concrete lower layer (2) is designed with a PAC-20 gradation, with a thickness of 4 cm to 6 cm and a void ratio of 18% to 25%; The open-graded asphalt stabilized macadam base (3) adopts the ATPB-25 grading design, with a thickness of 30cm-36cm and a void ratio between 20% and 25%; The graded crushed stone subbase (4) has a thickness of 25 cm to 30 cm and a void ratio of not less than 14%.

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