Patent ID: 12252851

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The invention will be described in more detail below with reference to specific embodiments. However, the embodiments described below are merely illustrative and should not be construed as limiting the scope of the foregoing subject matter of the invention, and all technologies implemented according to the contents of the invention fall within the scope of the invention.

Unless otherwise indicated, in the descriptions of specific embodiments of the invention, terms such as “upper”, “lower”, “left”, “right”, “center”, “inner”, “outer”, etc., which indicate orientation or positional relationship, are all expressions based on the orientation or positional relationship shown in the accompanying drawings or the orientation or positional relationship with which the product/equipment/device of the invention is commonly used. These terms of orientation or positional relationship are used only for the purpose of facilitating the description of the technical solutions of the invention or simplifying the description of the specific embodiments to facilitate a quick understanding of the technical solutions of the invention by those skilled in the art. Accordingly, they do not indicate or imply that a particular device/component/element must have a particular orientation or be constructed and operated in a particular positional relationship and should therefore not be construed as a limitation of the invention.

Furthermore, whenever the terms “horizontal”, “vertical”, “overhanging”, “parallel”, etc. are used, they do not imply that the corresponding device/component/element must be absolutely horizontal, vertical, overhanging or parallel, but may be slightly inclined or deviated. For example, “horizontal” merely implies that its orientation is more horizontal than “vertical” and does not mean that the structure must be completely horizontal, but may be slightly inclined. Alternatively, it can simply be understood that when the corresponding device/component/element is set in a direction such as “horizontal”, “vertical”, “overhanging”, “parallel”, etc., it can be set with an error/deviation of +10%, preferably within +8%, more preferably within +6%, even more preferably within +5%, and most preferably within +4% with respect to the corresponding directional setting. As long as the corresponding device/component/element is still able to perform its function in the solutions of the invention within these error/deviation ranges.

Furthermore, whenever expressions such as “first”, “second”, “third,” etc. are used in the terms, they are merely descriptions used to distinguish the same or similar components and should not be construed as emphasizing or implying the relative importance of any particular element.

Furthermore, in the descriptions of embodiments of the invention, “several”, “a plurality of” or “many” means at least 2. This can be any of 2, 3, 4, 5, 6, 7, 8, 9, or even more than 9.

Furthermore, in the description of technical solutions of the invention, unless otherwise expressly indicated/defined/restricted, wherever the terms “provide”, “install”, “interconnect”, “connect”, “mix”, “lay” and “arrange” are used, they should be interpreted in a broad sense, e.g., they may be a fixed connection, a removable connection, or an integral connection. It may also include welding, riveting, bolting, threading, and other means of connection commonly used in the field. This connection may be a mechanical connection, an electrical connection, or a telecommunications connection. It may also be a direct connection, an indirect connection through an intermediate medium, or an internal connection of two elements.

In the related art, phase change material has been added to the pavement, and the phase transition of the phase change material has been used to store a large amount of heat, thereby preventing heat transfer downwards and reducing the warming rate of the pavement. However, the phase change material is usually provided in the surface layer of the pavement, which is susceptible to abrasion and damage during long-term use, resulting in a reduction in the energy storage performance of the phase change material. In addition, the dosage accuracy cannot be guaranteed because the dosage of the phase change material is usually controlled by experience. Therefore, the technical solutions of the present application have been developed to solve such problems, which are described below with reference to the figure.

One aspect of the invention provides a method of calculating the dosage of phase change coarse aggregate30in a thermoregulating cement-stabilized layer, wherein a thermoregulating pavement typically comprises a surface layer10, a thermoregulating cement-stabilized layer20, and a subbase layer50provided in sequence, and the calculation method may comprise the following steps.

Firstly, a regulatory temperature difference4T of the thermoregulating cement-stabilized layer20in the thermoregulating pavement is set, wherein the regulatory temperature difference ΔT is the difference between the peak temperature T2of the thermoregulating cement-stabilized layer20and the peak temperature Ty of the conventional cement-stabilized layer, in which the thermoregulating cement-stabilized layer20is mixed with a phase change coarse aggregate30and the conventional cement-stabilized layer is not mixed with a phase change coarse aggregate30. That is, the thermoregulating cement-stabilized layer20can be formed by mixing a phase change coarse aggregate30into the conventional cement-stabilized layer, wherein the phase change coarse aggregate30contains a phase change material. As a result, the phase transition of the phase change material stores a large amount of heat, thereby allowing the peak temperature of the cement-stabilized layer to be reduced from T1to T2.

Then, a regulatory heat ΔQ is calculated based on the regulatory temperature difference, wherein when the temperature of the conventional cement-stabilized layer is elevated by the regulatory temperature difference ΔT, then the heat absorbed by the conventional cement-stabilized layer is the regulatory heat ΔQ, i.e., the heat that can be absorbed by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20when the temperature of the thermoregulating cement-stabilized layer20is elevated by the regulatory temperature difference ΔT.

Finally, a volume V3occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20is calculated based on the regulatory heat ΔQ.

In the present invention, the phase change coarse aggregate30is mixed for the purpose of reducing the peak temperature of the cement-stabilized layer, such as reducing the peak temperature of the cement-stabilized layer from T1to T2, where T1can be construed as the peak temperature of the conventional cement-stabilized layer and T2can be construed as the peak temperature of thermoregulating cement-stabilized layer20. Based on this, first the regulatory temperature difference ΔT=T2−T1is calculated, then the regulatory heat ΔQ is calculated, and finally, the volume V3occupied by the phase change coarse aggregate30in the regulated temperature stabilizing layer20is calculated.

As a result, since the phase change coarse aggregate30is mixed into the thermoregulating cement-stabilized layer20instead of the surface layer10, the phase change coarse aggregate30can be protected from abrasion and damage, which in turn ensures the energy storage capability of the phase change coarse aggregate30. On the other hand, if the phase change coarse aggregate30is mixed in too small of an amount, the expected regulatory temperature difference will not be achieved, and the peak temperature of the cement-stabilized layer will not be reduced to the expected value, thus failing to provide sufficient protection to the pavement. Especially for the permafrost subgrade, the pavement will experience subgrade damage such as thermal thawing and settlement if the cement-stabilized layer fails to achieve the expected regulatory temperature difference. In contrast, if the phase change coarse aggregate30is mixed in an excessive amount, the investment cost of the pavement will be increased and will result in wasted phase change material. Therefore, the dosage of phase change coarse aggregate30can be accurately controlled while effectively reducing the peak temperature by the above calculation. Especially for the permafrost subgrade, the material cost of phase change coarse aggregate30can be reduced while effectively reducing the peak temperature. Furthermore, in the process of pavement construction, the expected protection effect can be achieved while reducing the investment cost of the pavement, which is economically beneficial. Furthermore, the application scenario of the thermoregulating pavement according to the present invention is usually in permafrost areas, where the metal shell of the phase change coarse aggregate has good thermal conductivity, which enables the phase change coarse aggregate30to perform the function of phase change energy storage quickly and fully, thus preventing the heat from being transferred downward and protecting the permafrost.

In a preferred embodiment of the invention, before setting the regulatory temperature difference of thermoregulating cement-stabilized layer20, the method further comprises a step of calculating the peak temperature T2of thermoregulating cement-stabilized layer20based on the peak temperature Ty of the conventional cement-stabilized layer, wherein the peak temperature Ty of the conventional cement-stabilized layer can be obtained from an actual measurement.

In a preferred embodiment of the invention, the peak temperature of thermoregulating cement-stabilized layer20is calculated by using Equation

T2=t2-t1t2′-t1′·T1;
where T2is the peak temperature of thermoregulating cement-stabilized layer20, T, is the peak temperature of the conventional cement-stabilized layer, t1is the exothermic onset time of the conventional cement-stabilized layer, t2is the exothermic termination time of the conventional cement-stabilized layer, t1′ is the exothermic onset time of thermoregulating cement-stabilized layer20, and t2′ is the exothermic termination time of thermoregulating cement-stabilized layer20. The exothermic onset time can be construed as the timing at which the phase change material starts performing its function when the external temperature is higher than the phase transition temperature of the phase change material. The exothermic termination time can be construed as the timing at which the phase change material stops performing its function when the external temperature is lower than the phase transition temperature of the phase change material. In the specific calculation process, T1, t1, t2, t1′ and t2′ are determined by a specific measurement. Among them, tr′=t1can be set in order to facilitate the calculation.

In a preferred embodiment of the invention, after calculating the volume V3occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20, the method further comprises a step of calculating the mixing ratio n of the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20based on the volume V3occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20.

In a preferred embodiment of the invention, the mixing ratio n of the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20is calculated by using Equation

n=V3V0′+V2+V3,
where n is the mixing ratio of phase change coarse aggregate30in the thermoregulating cement-stabilized layer20, V2is the volume occupied by the conventional coarse aggregate40in the thermoregulating cement-stabilized layer20and V2≥0, wherein V2=0 means that only phase change coarse aggregate30is provided in the thermoregulating cement-stabilized layer20, V2>0 means that both the phase change coarse aggregate30and the conventional coarse aggregate40are provided in the thermoregulating cement-stabilized layer20, V0is the volume occupied by substances other than the conventional coarse aggregate40and the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20, and V3is the volume occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20.

Furthermore, the mixing ratio n is usually a percentage, so the above equation is also denoted as

n=V3V0′+V2+V3×100⁢%.

In a preferred embodiment of the invention, the regulatory heat is calculated by using Equation ΔQ=C0ρ0V0ΔT+c1β1ΔT, where ΔT=T2−T1, ΔT is the regulatory temperature difference, T2is the peak temperature of thermoregulating cement-stabilized layer20, T1is the peak temperature of the conventional cement-stabilized layer, ΔQ is the regulatory heat, c0is the specific heat capacity of substances other than the conventional coarse aggregate40in the conventional cement-stabilized layer, ρ0is the density of substances other than the conventional coarse aggregate40in the conventional cement-stabilized layer, V0is the volume of substances other than the conventional coarse aggregate40in the conventional cement-stabilized layer, c/is the specific heat capacity of the conventional coarse aggregate40in the conventional cement-stabilized layer, ρ1is the density of the conventional coarse aggregate40in the conventional cement-stabilized layer, and V1is the volume of the conventional coarse aggregate40in the conventional cement-stabilized layer.

Furthermore, the conventional cement-stabilized layer and the thermoregulating cement-stabilized layer20satisfy Equations V0′=V0and V1=V2+V3. That is, the mixing of the phase change coarse aggregate30is conducted by an equal volume replacement method. Specifically, the volume of the conventional coarse aggregate40in the conventional cement-stabilized layer is V1, and the thermoregulating cement-stabilized layer20is formed by replacing the conventional coarse aggregate40in the conventional cement-stabilized layer with an equal volume of the phase change coarse aggregate30having a volume of V3, so that the volume of the conventional coarse aggregate in the thermoregulating cement-stabilized layer20is reduced to V2, i.e., V1=V2+V3, while the volume of the remaining material is unchanged, i.e., V0′=V0.

In a preferred embodiment of the invention, the volume occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20is calculated by using Equation

V3=Δ⁢QΔ⁢H·ρ3,
where V3is the volume occupied by the phase change coarse aggregate30in the thermoregulating cement-stabilized layer20, ΔH is the latent heat of phase change coarse aggregate30, and ρ3is the density of phase change coarse aggregate30.

Another aspect of the invention provides a method of manufacturing the phase change coarse aggregate30for use in the above-described dosage calculation method, and the manufacturing method comprises the steps of fabricating a metal shell, the shell being irregularly shaped to allow the phase change coarse aggregates30to be interlocked with each other, thereby ensuring the strength of the pavement structure;drilling a hole in the metal shell;injecting a phase change material into the metal shell through the hole in the metal shell; andsealing the hole of the metal shell by welding or the like.

Yet another aspect of the invention provides a thermoregulating pavement which employs the above-described method. The thermoregulating pavement is a composite pavement structure, and more particularly, the thermoregulating pavement includes a surface layer10, a thermoregulating cement-stabilized layer20, and a subbase layer50provided in sequence. The thermoregulating cement-stabilized layer20is provided with a phase change coarse aggregate30, which can reduce the peak temperature of the thermoregulating pavement, postpone and delay the time at which the thermoregulating cement-stabilized layer20reaches the peak temperature, thereby achieving the effect of protecting the pavement. Meanwhile, since the phase change coarse aggregate30is provided away from the surface layer10, abrasion damage to the phase change coarse aggregate30is reduced and the energy storage performance of the phase change coarse aggregate30is ensured.

In a preferred embodiment of the invention, the phase change coarse aggregate30may include a metal shell and a phase change material provided in the metal shell. Wherein the phase change material can be composed of inorganic, organic or composite materials, such as paraffin, polyols, fatty acids or the like, and the phase change material satisfies a supercooling degree of less than or equal to 5.0° C., a phase transition temperature of greater than or equal to 10.0° C., and a latent heat of greater than or equal to 120.0 J/g, so as to effectively utilize the phase change energy storage ability of the phase change material and then fully protect the permafrost when the pavement according to the present invention is applied in permafrost areas. The metal shell can be composed of materials such as steel and has a particle size of 0.075 mm to 53.0 mm. The metal shell can be provided to encapsulate and protect the phase change material therein, and on the other hand, the good thermal conductivity of the metal can be utilized to allow the phase change material to realize its effects.

In a preferred embodiment of the invention, the thermoregulating cement-stabilized layer20is mixed with a conventional coarse aggregate40, the conventional coarse aggregate40being composed of natural rock, pebbles or mine waste rock or the like, so as to be used as a framework for the concrete in the pavement and to improve the structural stability of the concrete in the pavement.

In a preferred embodiment of the invention, the phase change coarse aggregate30has an irregular shape and a rough surface, and as compared to a regular shape such as a circle or a rectangle, the irregular and rough shape design of the phase change coarse aggregate30allows the phase change coarse aggregate30to interlock with other materials in the thermoregulating cement-stabilized layer20, so as to generate a larger internal frictional resistance to ensure that the structure of the thermoregulating cement-stabilized layer20is fixed and to ensure that the thermoregulating pavement is structurally strong.

All the above are only some of the preferred embodiments of the invention and are not intended to limit the invention. The invention may also have a variety of other embodiments, and without departing from the spirit and substance of the invention, a person skilled in the art may make various changes and modifications in accordance with the invention, but such changes and modifications shall fall within the protection scope of the invention.