Assembly type step temperature control roadbed structure suitable for permafrost region

Abstract

The invention provides an assembly type step temperature control roadbed structure suitable for permafrost regions, and belongs to the technical field of roadbeds, the assembly type step temperature control roadbed structure comprises a heat insulation layer, a soil-rock mixture layer, a multi-layer phase change roadbed layer and a pavement structure layer which are sequentially arranged from bottom to top, and meanwhile, a phase change layer and a heat insulation layer are laid on a roadbed slope and part of slope toe horizontal sections. Wherein each phase change roadbed layer comprises a plurality of phase change blocks, and the adjacent phase change blocks are connected together in a splicing manner; the phase change block accommodating cavity is filled with the phase change material, so that the phase change material is prevented from leaking due to extrusion; the phase-change temperatures of the phase-change materials in the phase-change roadbed layers are different, and the corresponding phase-change materials are subjected to phase change at different environment temperatures so as to regulate and control the temperature, so that the aim of continuously controlling the temperature is fulfilled; meanwhile, the novel roadbed adopts an assembly type construction technology, most structures are prefabricated parts, the construction and later maintenance efficiency can be improved, and the novel roadbed is an important exploration for few-person construction in permafrost regions.

Description

Technical Field

[0001] The invention belongs to the technical field of roadbeds, and in particular relates to an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas. Background Art

[0002] When constructing highways in permafrost areas, wide roadbeds, thick pavement and black asphalt overlays are usually used. Compared with ordinary secondary roads, the above highway structures will increase the heat flux at the bottom of the roadbed, enhance the "heat blanket effect", seriously weaken the thermal stability of the frozen soil, and increase the risk of thawing settlement.

[0003] The reason for the thawing disease in permafrost areas is that the thermal stability of the permafrost is destroyed, and the heat released is less than the heat absorbed, resulting in the melting of the permafrost. The existing phase change temperature control technology usually mixes the phase change material with the road surface material such as asphalt and cement, acting as a medium for heat absorption and release to control the temperature. However, the above-mentioned technology mostly uses a phase change material with a fixed and single phase change point. When the temperature does not reach the phase change point, the phase change material does not work. When the temperature exceeds the phase change point, the phase change material cannot continue to control the temperature because all phase changes have been completed at the phase change point. At the same time, since the phase change material directly bears the traffic load, it is easy to leak due to extrusion, which leads to reduced service durability and poor temperature control effect. In addition, the permafrost area presents the environmental characteristics of long-term low temperature, high frequency freeze-thaw, and extreme hypoxia. Assembly, less manpower, and low time consumption are the engineering requirements and development trends for paving and maintaining roads in this area, but the existing technology is complex, the process is cumbersome, and it takes a long time, and its applicability in permafrost areas is low. Summary of the invention

[0004] The embodiment of the present invention provides an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas, aiming to solve the technical problems in the prior art that phase change materials cannot continuously control temperature in a permafrost environment, are easily squeezed and leak, and have complex construction processes and cumbersome procedures.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] Provided is an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas, comprising a heat-insulating layer, a soil-rock mixture layer, a multi-layer phase-change roadbed layer and a pavement structure layer arranged in sequence from bottom to top;

[0007] Among them, each layer of phase change road base includes a plurality of phase change blocks, and adjacent phase change blocks are connected together in a splicing manner; each phase change block has at least one accommodating cavity inside, and the accommodating cavity is filled with a composite shaped phase change material.

[0008] In a possible implementation, the phase change block is prefabricated with high thermal conductivity cement concrete, the length of the phase change block ranges from 200 cm to 300 cm, the width ranges from 40 cm to 60 cm, and the height ranges from 10 cm to 15 cm; wherein the length, width, and height ratio of the phase change block is 20:4:1.

[0009] In a possible implementation, the volume ratio of the accommodation cavity to the phase change block is greater than 65%.

[0010] In a possible implementation, when the phase change block is prefabricated, a semi-finished product with an open accommodating cavity is first prefabricated, and then the composite shaped phase change material is filled into the accommodating cavity, and finally the accommodating cavity is sealed.

[0011] In a possible implementation, the mass components of high thermal conductivity cement concrete are: 12 to 15 parts of cement, 1 to 2 parts of slag powder, 25 to 35 parts of sand, 45 to 55 parts of crushed stone, 4 to 5 parts of water, and 0.24 to 0.45 parts of graphene-thermal conductive fiber dispersion slurry.

[0012] In a possible implementation, in the graphene-thermal conductive fiber dispersion slurry, by mass, the graphene suspension is 45-50%, the polycarboxylate water reducer is 45-50%, the viscosity regulator is 1-8%, and the thermal conductive fiber is 1-8%; the thermal conductivity of the high thermal conductivity cement concrete is greater than 15W / (m·K).

[0013] In a possible implementation, among the four side walls of the phase change block, two opposite side walls form a group of splicing parts, and each group of splicing parts includes grooves and convex strips; when splicing, the convex strips on the phase change block are plugged into the grooves on the adjacent phase change blocks; a splicing seam is formed between the convex strips and the grooves, and a flexible filling material is arranged in the splicing seam.

[0014] In a possible implementation, the multi-layer phase change road base layer includes, from bottom to top, a low-temperature phase change layer, a medium-temperature phase change layer, and a high-temperature phase change layer; the laying directions of the phase change blocks of adjacent layers are at a preset angle.

[0015] In a possible implementation, a phase change layer and a heat insulation layer are provided on the roadbed slope and part of the horizontal section at the foot of the slope, wherein the phase change layer is the inner layer and the heat insulation layer is the outer layer;

[0016] Among them, the top of the thermal insulation layer and the phase change layer are flush with the top surface of the pavement structure layer, and the bottom extends 1m outward from the foot of the roadbed slope and is anchored to the roadbed slope by anchor nails.

[0017] In a possible implementation, the composite shaped phase change material includes a matrix material, a nucleating agent and a temperature regulating agent, and the composite shaped phase change material is divided into a low-temperature phase change material, a medium-temperature phase change material and a high-temperature phase change material, which are respectively filled into the phase change blocks of the low-temperature, medium-temperature and high-temperature phase change layers;

[0018] Among them, the phase change temperature of low-temperature phase change material is 0℃~5℃, the phase change temperature of medium-temperature phase change material is 10℃~15℃, and the temperature of high-temperature phase change material is 20℃~25℃; the heat storage density of all phase change materials is greater than 160kJ / kg.

[0019] The present invention provides an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas. Compared with the prior art, the thermal insulation layer, soil-rock mixture layer, multi-layer phase change roadbed and pavement structure layer are arranged from bottom to top. In the warm season, the multi-layer phase change roadbed can undergo phase change and absorb heat in stages, so as to gradually reduce the heat transmitted from the roadbed to the underlying frozen soil; in the cold season, the multi-layer phase change roadbed can undergo phase change and release heat, increase the road surface temperature, and achieve ice and snow melting on the road surface. The composite shaped phase change material in the present application is filled into the accommodating cavity of the phase change block, so the phase change block bears the traffic load, and the composite shaped phase change material inside the phase change block does not bear the traffic load, avoiding leakage due to extrusion, and improving service durability; through the temperature control method of the above-mentioned multi-layer phase change roadbed, the heat can be absorbed or released layer by layer, thereby achieving the purpose of continuous temperature regulation; at the same time, the new roadbed adopts an assembled construction process, and most of the structures are prefabricated parts, which can improve the efficiency of construction and later maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas provided by an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a state in which a plurality of layers of phase change blocks are laid out in an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas provided by an embodiment of the present invention;

[0022] Figure 3 for Figure 2 The enlarged schematic diagram of the middle A part;

[0023] Figure 4 A cross-sectional schematic diagram of a multi-layer phase change block of an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas provided by an embodiment of the present invention;

[0024] Figure 5 for Figure 4 The enlarged schematic diagram of the middle B part;

[0025] Figure 6 A schematic diagram of a single phase change block portion of an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas provided in an embodiment of the present invention.

[0026] Explanation of the accompanying drawings: 1. Insulation layer; 2. Soil-rock mixture layer; 3. Multi-layer phase change road base layer; 31. Low-temperature phase change layer; 32. Medium-temperature phase change layer; 33. High-temperature phase change layer; 4. Pavement structure layer; 5. Phase change block; 51. Accommodating cavity; 52. Groove; 53. Raised strip; 6. Phase change layer; 7. Anchor nail. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] Please also read Figures 1 to 6 , now an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas provided by the present invention is described. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas comprises an insulation layer 1, a soil-rock mixture layer 2, a multi-layer phase change roadbed 3 and a pavement structure layer 4 arranged in sequence from bottom to top. Among them, each layer of the phase change roadbed comprises a plurality of phase change blocks 5, and adjacent phase change blocks 5 are connected together in a splicing manner; each phase change block 5 has at least one accommodating cavity 51 inside, and the accommodating cavity 51 is filled with a composite shaped phase change material.

[0029] The present invention provides an assembled stepped temperature-controlled roadbed structure suitable for permafrost areas. Compared with the prior art, the present invention has an insulation layer 1, a soil-rock mixture layer 2, a multi-layer phase change roadbed layer 3 and a pavement structure layer 4 arranged from bottom to top. In the warm season, the multi-layer phase change roadbed layer 3 can undergo phase change in stages and absorb heat to gradually reduce the amount of heat transferred from the roadbed to the underlying frozen soil; in the cold season, the multi-layer phase change roadbed layer 3 can undergo phase change and release heat to increase the road surface temperature to achieve ice and snow melting on the road surface. The composite shaped phase change material in the present application is filled into the accommodating cavity 51 of the phase change block 5, so the phase change block 5 bears the traffic load, and the composite shaped phase change material inside the phase change block 5 does not bear the traffic load, thereby avoiding leakage due to squeezing, and improving service durability; through the temperature control method of the above-mentioned multi-layer phase change roadbed 3, it is possible to achieve layer-by-layer absorption or release of heat, thereby achieving the purpose of continuous temperature regulation; the permafrost area presents environmental characteristics of long-term low temperature, high-frequency freezing and thawing, and extreme hypoxia. The new roadbed adopts an assembled construction process, and most of the structures are prefabricated parts, which can improve the efficiency of construction and later maintenance, and achieve the goal of less manpower and low time consumption.

[0030] In some embodiments, Figures 1 to 6As shown, the phase change block 5 is prefabricated with high thermal conductivity cement concrete, the length of the phase change block 5 ranges from 200cm to 300cm, the width ranges from 40cm to 60cm, and the height ranges from 10cm to 15cm; wherein, the length, width, and height ratio of the phase change block 5 is 20:4:1; and the volume ratio of the accommodating cavity 51 to the phase change block 5 is greater than 65%. The phase change block 5 is a long strip structure, which is convenient for prefabrication and splicing.

[0031] It should be noted that the phase change block 5 is prefabricated with high thermal conductivity cement concrete, which can improve the strength of the phase change block 5 and facilitate the phase change block 5 to bear the traffic load transmitted from the upper part; since the accommodating cavity 51 occupies more than 65% of the volume of the phase change block, the composite shaped phase change material in the accommodating cavity 51 can better play a temperature control role; the composite shaped phase change material is arranged in the accommodating cavity 51 of the phase change block 5, and the composite shaped phase change material does not need to bear the traffic load transmitted from the upper part, so the leakage of the composite shaped phase change material due to extrusion can be reduced.

[0032] In some embodiments, Figures 1 to 6 As shown, when the phase change block 5 is prefabricated, a semi-finished product with an open accommodating cavity 51 is first prefabricated, and then the composite shaped phase change material is filled into the accommodating cavity 51, and finally the accommodating cavity 51 is sealed.

[0033] In some embodiments, Figures 1 to 6 As shown, the mass components of high thermal conductivity cement concrete are: 12-15 parts of cement, 1-2 parts of slag powder, 25-35 parts of sand, 45-55 parts of crushed stone, 4-5 parts of water, and 0.24-0.45 parts of graphene-thermal conductive fiber dispersion slurry; in the graphene-thermal conductive fiber dispersion slurry, the mass components include 45-50% of graphene suspension, 45-50% of polycarboxylate water reducer, 1-8% of viscosity modifier, and 1-8% of thermal conductive fiber.

[0034] It should be noted that, through the above mass components, the thermal conductivity of the prefabricated phase change block 5 can be greater than 15 W / (m·K), so that the composite shaped phase change material inside the phase change block 5 can better play a role in temperature control.

[0035] In some embodiments, Figures 1 to 6 As shown, among the four side walls of the phase change block 5, the two opposite side walls form a group of splicing parts, and each group of splicing parts includes a groove 52 and a convex strip 53; when splicing, the convex strip 53 on the phase change block 5 is plugged into the groove 52 on the adjacent phase change block 5; a splicing seam is formed between the convex strip 53 and the groove 52, and a flexible filling material is arranged in the splicing seam.

[0036] It should be noted that by setting grooves 52 and convex strips 53 on the phase change block 5, the connection between adjacent phase change blocks 5 can be strengthened and the occurrence of breakage of the phase change block 5 at the connection position can be reduced; the flexible filling material includes acrylic adhesive, polyurethane adhesive or epoxy adhesive. By setting a flexible filling material in the joint seam, the adjacent phase change blocks 5 can be better fixed together.

[0037] For example, a flexible cushion is laid between the upper and lower adjacent layers of phase change roadbed, and the flexible cushion is made of fine sand, slag, fly ash or silty soil with good properties, and the thickness of the flexible cushion is within 5 cm. Due to the prefabrication process, the upper and lower surfaces of the phase change block are rarely completely smooth planes. By adding a flexible cushion, the protruding part of the upper phase change layer can be prevented from directly squeezing the lower phase change layer, causing stress concentration and then damaging the lower phase change layer.

[0038] In some embodiments, Figures 1 to 6 As shown, the multi-layer phase change road base layer 3 includes a low-temperature phase change layer 31, a medium-temperature phase change layer 32 and a high-temperature phase change layer 33 from bottom to top; the laying direction of the phase change blocks 5 of adjacent layers is a preset angle.

[0039] Exemplarily, in this embodiment, the laying angles of the phase change blocks 5 in adjacent layers are perpendicular to each other, so the phase change blocks 5 in adjacent layers are arranged in a crisscross pattern.

[0040] Exemplarily, each layer of phase change road base layer can be paved with a layer of phase change blocks 5, or can be paved with multiple layers of phase change blocks 5, and the low-temperature phase change layer 31 is taken as an example for explanation; the low-temperature phase change layer 31 can be paved with a layer of phase change blocks 5, or can be paved with two or more layers of phase change blocks 5; the phase change blocks 5 in the low-temperature phase change layer 31 are filled with the same composite shaped phase change material, so the overall phase change temperature of the low-temperature phase change layer 31 is consistent.

[0041] In some embodiments, Figures 1 to 6 As shown, the composite shaped phase change material includes a matrix material, a nucleating agent and a temperature regulating agent. The composite shaped phase change material is divided into a low-temperature phase change material, a medium-temperature phase change material and a high-temperature phase change material; wherein, the phase change temperature of the low-temperature phase change material is 0°C to 5°C, the phase change temperature of the medium-temperature phase change material is 10°C to 15°C, the temperature of the high-temperature phase change material is 20°C to 25°C, and the heat storage density of all phase change materials is greater than 160 kJ / kg.

[0042] It should be noted that the low-temperature phase change material is filled into the phase change block 5 of the low-temperature phase change layer 31 , the medium-temperature phase change material is filled into the phase change block 5 of the medium-temperature phase change layer 32 , and the high-temperature phase change material is filled into the phase change block 5 of the high-temperature phase change layer 33 .

[0043] Exemplarily, a plurality of phase change materials with different phase change temperatures are prepared, and the phase change materials are encapsulated in porous aggregates using interface encapsulation technology to obtain composite fixed phase change materials with various phase change temperatures; in the interface encapsulation technology, the encapsulation material forms a thin film on the surface of the porous aggregate to prevent leakage when the phase change material changes phase; the encapsulation material can be epoxy resin or styrene acrylic emulsion. The interface encapsulation technology is a prior art and will not be described in detail here.

[0044] Exemplarily, the base material of the low-temperature composite shaping phase change material can be selected as calcium chloride hexahydrate (CaCl2·6H2O), the nucleating agent can be selected as strontium chloride hexahydrate (SrCl2·6H2O), and the temperature regulator can be selected as carbonamide (CH4N2O); the base material of the medium-temperature composite shaping phase change material can be selected as calcium chloride hexahydrate (CaCl2·6H2O), the nucleating agent can be selected as strontium chloride hexahydrate (SrCl2·6H2O), and no temperature regulator is required; the base material of the high-temperature composite shaping phase change material can be selected as disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), the nucleating agent can be selected as sodium silicate nonahydrate (Na2SiO3·9H2O), and no temperature regulator is required.

[0045] Exemplarily, the porous aggregate may be selected from vermiculite, ceramsite, perlite and diatomaceous earth.

[0046] In some embodiments, Figures 1 to 6 As shown, a phase change layer 6 and a thermal insulation layer 1 are provided on the embankment slope and part of the horizontal section at the foot of the slope, wherein the phase change layer 6 is the inner layer and the thermal insulation layer 1 is the outer layer; wherein the tops of the thermal insulation layer 1 and the phase change layer 6 are flush with the top surface of the pavement structure layer 4, and the bottoms extend 1m outward from the foot of the embankment slope and are anchored to the embankment slope by anchor nails 7.

[0047] Exemplarily, the phase change layer 6 of the roadbed slope and part of the horizontal section of the slope foot is not limited to a single-layer phase change block 5, but can also be a multi-layer phase change block 5; the heat insulation layer 1 uses a heat insulation material, which can be a polystyrene foam board or a polystyrene extruded board; the thickness of the heat insulation layer 1 is 10 cm, and the thickness of the phase change layer 6 is 10 cm to 15 cm; the top of the heat insulation layer 1 and the phase change layer 6 are in the same horizontal plane, and the top of the heat insulation layer 1 and the top of the phase change layer 6 are flush with the pavement structure layer 4; the bottom of the heat insulation layer 1 and the phase change layer 6 extends outward from the roadbed slope foot by 1m, and the heat insulation layer 1 and the phase change layer 6 are anchored to the roadbed slope by anchor nails 7. When anchoring by anchor nails 7, the anchor nails 7 cannot pass through the accommodating cavity 51 of the phase change block 5.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An assembled stepped temperature-controlled roadbed structure suitable for permafrost areas, characterized in that: It includes a heat insulation layer, a soil-rock mixture layer, a multi-layer phase change road base layer and a pavement structure layer arranged in sequence from bottom to top; Among them, each layer of phase change road base includes a plurality of phase change blocks, and adjacent phase change blocks are connected together in a splicing manner; each phase change block has at least one accommodating cavity inside, and the accommodating cavity is filled with a composite shaped phase change material.

2. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 1, characterized in that: The phase change block is prefabricated with high thermal conductivity cement concrete. The length of the phase change block ranges from 200cm to 300cm, the width ranges from 40cm to 60cm, and the height ranges from 10cm to 15cm. Among them, the length, width and height ratio of the phase change block is 20:4:

1.

3. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 2, characterized in that: The volume ratio of the accommodating cavity to the phase change block is greater than 65%.

4. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 2, characterized in that: When the phase change block is prefabricated, a semi-finished product with an open accommodating cavity is first prefabricated, and then the composite shaped phase change material is filled into the accommodating cavity, and finally the accommodating cavity is sealed.

5. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 2, characterized in that: The mass components of high thermal conductivity cement concrete are: 12 to 15 parts of cement, 1 to 2 parts of slag powder, 25 to 35 parts of sand, 45 to 55 parts of crushed stone, 4 to 5 parts of water, and 0.24 to 0.45 parts of graphene-thermal conductive fiber dispersion slurry.

6. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 5, characterized in that: In the graphene-thermal conductive fiber dispersion slurry, by mass, the graphene suspension is 45-50%, the polycarboxylate water reducer is 45-50%, the viscosity regulator is 1-8%, and the thermal conductive fiber is 1-8%; The thermal conductivity of high thermal conductivity cement concrete is greater than 15W / (m·K).

7. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 1, characterized in that: Among the four side walls of the phase change block, two opposite side walls form a group of splicing parts, and each group of splicing parts includes grooves and convex strips; when splicing, the convex strips on the phase change block are plugged into the grooves on the adjacent phase change blocks; a splicing seam is formed between the convex strips and the grooves, and a flexible filling material is arranged in the splicing seam.

8. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 1, characterized in that: The multi-layer phase change road base layer includes a low-temperature phase change layer, a medium-temperature phase change layer and a high-temperature phase change layer from bottom to top; the laying directions of the phase change blocks of adjacent layers are at a preset angle.

9. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 1, characterized in that: Phase change layer and thermal insulation layer are set on the roadbed slope and part of the horizontal section at the foot of the slope, with the phase change layer as the inner layer and the thermal insulation layer as the outer layer; Among them, the top of the insulation layer and the phase change layer are flush with the top surface of the pavement structure layer, and the bottom extends 1m outward from the foot of the roadbed slope and is anchored to the roadbed slope by anchor nails.

10. The assembled stepped temperature-controlled roadbed structure suitable for permafrost areas according to claim 1, characterized in that: The composite shaped phase change material includes a matrix material, a nucleating agent and a temperature regulating agent. The composite shaped phase change material is divided into a low-temperature phase change material, a medium-temperature phase change material and a high-temperature phase change material, which are respectively filled into the phase change blocks of the low-temperature, medium-temperature and high-temperature phase change layers; Among them, the phase change temperature of low-temperature phase change material is 0℃~5℃, the phase change temperature of medium-temperature phase change material is 10℃~15℃, and the temperature of high-temperature phase change material is 20℃~25℃; the heat storage density of all phase change materials is greater than 160kJ / kg.

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