A method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets

Abstract

This invention discloses a method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets, specifically relating to the material design field of self-heating adhesive layers for paved asphalt blankets. The self-heating adhesive layer for paved asphalt blankets consists of an adhesive and a heating agent. The adhesive is composed of SBS modified asphalt, and the heating agent is a uniform mixture of reduced iron powder, carbon powder, sodium chloride, and calcium oxide. This invention determines the optimal composition ratio of each component in the heating agent through heating tests, then calculates the unit heat output of the heating agent at this composition ratio, and finally designs the application ratio of the heating agent and adhesive based on the heat transfer characteristics between pavement layers. By calculating the application ratio of the heating agent and adhesive in the self-heating adhesive layer of paved asphalt blankets, this invention avoids the adhesive failing to heat to the required temperature due to an insufficient ratio of heating agent and adhesive, while simultaneously avoiding pavement layer separation due to an excessive ratio of heating agent and adhesive.

Description

Technical Field

[0001] This invention relates to the field of material proportion design for self-heating adhesive layers of paved asphalt blankets, and specifically to a method for designing the material composition proportions of self-heating adhesive layers of paved asphalt blankets. Background Technology

[0002] Paved asphalt blankets have gained widespread attention as a new method for road paving and maintenance due to their fast construction speed and ease of operation. However, since they are separate pavement structural layers from the existing pavement, their interlayer bonding performance has a significant impact on pavement stability and is a key aspect of construction. According to relevant research, self-heating adhesive layers in paved asphalt blankets continuously release heat through a heating agent to alter the binder's fluidity, which can be used in the construction of paved asphalt blankets to improve their interlayer bonding performance with the existing pavement. However, the material composition ratio of the self-heating adhesive layer in paved asphalt blankets has a significant impact on pavement performance. When the ratio of heating agent to binder is too small, the binder will not heat up to the required temperature due to the excess binder and insufficient heating agent, resulting in weak interlayer bonding. When the ratio of heating agent to binder is too large, the excess heating agent will detach from the binder surface, leading to localized voids or overall delamination between pavement layers, severely affecting the normal use of the road. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets. This method overcomes the deficiencies of existing technologies by designing the optimal composition ratio of each material in the heating agent, calculating the unit heat output of the heating agent, and then calculating the spraying ratio of the heating agent and the adhesive in the self-heating adhesive layer of the paved asphalt blanket based on the heat transfer law between road layers. This improves the interlayer bonding performance between the paved asphalt blanket and the original road surface.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets, wherein the self-heating adhesive layer for paved asphalt blankets is composed of an adhesive and a heating agent. The adhesive is composed of SBS modified asphalt and is distributed in layers on the lower surface of the paved asphalt blanket. The heating agent is composed of reduced iron powder, carbon powder, sodium chloride and calcium oxide uniformly mixed and randomly sprinkled on the lower surface of the adhesive.

[0006] The material composition ratio design method for the self-heating adhesive layer of the paved asphalt blanket includes the following steps:

[0007] Step 1: Design the experimental ratio of reduced iron powder, carbon powder, and sodium chloride in the heating agent:

[0008] A1: Design the experimental ratio of carbon powder to reduced iron powder: keep the amount of reduced iron powder constant and select it uniformly within the initial molar ratio range. Group The ratio was used as the experimental ratio of carbon powder and reduced iron powder. Appropriate amounts of carbon powder were added to each mixture, and after uniform mixing, exothermic agent I was obtained. Its highest heating temperature was then tested. The relationship between the highest heating temperature and the experimental ratio of carbon powder to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to carbon powder at which the curve reached its peak was obtained. ;

[0009] A2: Design the experimental ratio of sodium chloride and reduced iron powder: Use the same amount of reduced iron powder as in A1, add carbon powder according to the experimental ratio determined in A1, and uniformly select the powder within the initial molar ratio range. Group The ratio was used as the experimental ratio of sodium chloride and reduced iron powder. Appropriate amounts of sodium chloride were added to each mixture, and after uniform mixing, exothermic agent II was obtained. Its maximum heating temperature was then tested. A curve showing the relationship between the highest heating temperature and the experimental ratio of sodium chloride to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to sodium chloride at which the curve reached its peak was obtained. ;

[0010] Step 2: Design the experimental proportion of calcium oxide in the heating agent and determine the optimal composition ratio of each material in the heating agent:

[0011] B1: Testing the highest heating temperature under different calcium oxide dosages: Add the above materials according to the dosage of reduced iron powder in step one, and the experimental ratio of reduced iron powder to carbon powder and sodium chloride, and select them uniformly within the initial molar ratio range. Group The ratio was used as the experimental ratio of calcium oxide and reduced iron powder. The appropriate amount of calcium oxide was added to each, and after uniform mixing, the exothermic agent III was obtained, and its maximum exothermic temperature was tested.

[0012] B2: Prepare composite specimens according to the highest heating temperature of exothermic agent III: Heat multiple groups of equal amounts of binder to the highest heating temperature of exothermic agent III in B1, select the heating reaction product of exothermic agent III corresponding to this temperature, evenly sprinkle it on the surface of the above binder, and obtain a composite specimen composed of binder and heating reaction product after rolling treatment.

[0013] B3: Design the experimental ratio of calcium oxide to reduced iron powder: After immersing the composite specimen in water, calculate the corresponding mass change rate. A curve showing the relationship between the mass change rate of the composite specimen and the experimental ratio of calcium oxide to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to calcium oxide at which the curve reached its peak was obtained. ;

[0014] B4: Calculate the mass ratio of each component of the heating agent: Based on the experimental ratios of reduced iron powder, carbon powder, sodium chloride, and calcium oxide in steps one and two (B3), calculate their mass fraction in the heating agent:

[0015]

[0016] In the formula: —Mass fraction (%) of each component in the heating agent; —The experimental proportions of each component material in the heating agent; —molar mass of each component material in the heating agent ( Of the parameters mentioned above, The materials referred to are reduced iron powder, carbon powder, sodium chloride, and calcium oxide, respectively.

[0017] Step 3: Calculate the unit calorific value of the heating agent:

[0018] Based on the composition ratio of the heating agent materials and the corresponding thermochemical reaction principles, the unit calorific value of the heating agent is calculated. :

[0019]

[0020] In the formula: —Heat output per unit of heating agent ; —The proportion of first-order reactions in the galvanic cell reaction; —The proportion of second-order reactions in the galvanic cell reaction; —The proportion of reduced iron powder in the heating agent (%); —The percentage of calcium oxide in the heating agent (%) —Enthalpy change of first-order reactions ; —Enthalpy change of second-order reaction ; —Enthalpy change of combination reactions ;

[0021] Step 4: Calculate the ratio of heating agent to binder;

[0022] Based on the heat transfer characteristics between layers and the unit heat output of the heating agent in step three, the ratio of heating agent to binder is calculated. :

[0023]

[0024] In the formula: —The ratio of heating agent to binder; —Specific heat capacity of adhesive ; —Temperature difference of the binder before and after the heating agent ignites ; — Thermal conductivity of the adhesive ; —The thermal conductivity of the original road surface .

[0025] Preferably, the chemical reactions of the heating agent material in steps one and two (B1) include galvanic cell reactions and combination reactions. The galvanic cell reaction is a redox reaction with reduced iron powder as the positive electrode, carbon powder as the negative electrode, and sodium chloride solution as the electrolyte solution. It includes first-order and second-order reactions. After the reduced iron powder and carbon powder undergo the galvanic cell reaction, unstable ferric hydroxide is produced, which continues to react in a high-temperature environment to produce ferrous oxide and ferric oxide. The thermochemical equations for the first-order and second-order reactions are as follows:

[0026] First-order reaction:

[0027] Second-order reaction:

[0028] The thermochemical equation for the combination reaction is:

[0029] ;

[0030] Preferably, the specific steps for immersing the composite specimen in water in step two (B3) are as follows:

[0031] ① For composite specimens with different test ratios of calcium oxide and reduced iron powder, weigh their mass as follows: ;

[0032] ②Immerse the composite specimen in water for 24 hours, remove it, dry it, and weigh it. ;

[0033] ③ Calculate the rate of change of mass of the composite specimen: .

[0034] Preferably, the initial molar ratio of reduced iron powder, carbon powder, sodium chloride, and calcium oxide in steps one and two (B1) is 1:1:2:2.

[0035] Preferably, the proportion of the first-order reaction in the galvanic cell reaction in step three is... for:

[0036]

[0037] In the formula: —The mass (g) of reduced iron powder in the exothermic agent; —The mass difference (g) of the exothermic agent before and after the reaction;

[0038] The proportion of the second-order reaction in the galvanic cell reaction in step three. for:

[0039] .

[0040] Beneficial effects:

[0041] (1) The present invention calculates the unit heat of the heating agent based on the material composition of the heating agent, and then, based on the heat transfer law between pavement layers, after considering the heating reaction type of the heating agent, the specific heat capacity and thermal conductivity of the binder, and the thermal conductivity of the original pavement, the proportion of heating agent and binder in the self-heating adhesive layer of the pavement asphalt blanket is quantified. Compared with the traditional method, the present invention considers the influence of the proportion of heating agent and binder on the bonding performance between the pavement asphalt blanket and the original pavement layers. At the same time, in the construction, the proportion of heating agent and binder in the self-heating adhesive layer of the pavement asphalt blanket can be obtained simply by substituting the relevant parameters. The operation is simple and the application is convenient.

[0042] (2) The present invention designs experiments based on the principle that the reducing agent loses electrons at the negative electrode and undergoes oxidation reaction in the galvanic cell reaction, the oxidizing agent gains electrons at the positive electrode and undergoes reduction reaction, and the combination reaction of calcium oxide and water is exothermic. The initial molar ratio of materials is designed first based on the law of charge conservation in the galvanic cell reaction and the law of mass conservation in the combination reaction. Then, the experimental ratio of reduced iron powder, carbon powder and sodium chloride is determined with the highest heating temperature as the index. Then, the corresponding materials are added according to the above experimental ratio. After that, different amounts of calcium oxide are added. Combined with heating test and immersion test, the experimental ratio of calcium oxide and reduced iron powder is determined. Thus, the experimental ratio of reduced iron powder, carbon powder, sodium chloride and calcium oxide in the heating agent is obtained. The designed experimental ratio ensures that the heating agent has the best heating effect during construction, and also makes the product after heating have good compatibility with the binder, and will not cause delamination between the paved asphalt blanket and the original road surface.

[0043] (3) This invention quantifies the spraying ratio of heating agent and adhesive in the self-heating adhesive layer of paved asphalt blanket, which can avoid the problem that the adhesive cannot be heated to the required temperature due to the ratio of heating agent and adhesive being too small during construction, resulting in weak bonding between pavement layers, or the pavement layers being partially delaminated or completely delaminated due to the ratio of heating agent and adhesive being too large, which seriously affects the normal use of the road.

[0044] (4) The present invention uses a mixture of reduced iron powder, carbon powder, sodium chloride and calcium oxide as a heating agent. The reduced iron powder, carbon powder and sodium chloride react in a galvanic cell reaction to release heat, and calcium oxide releases heat through a combination reaction. During the heating process of the heating agent, firstly, calcium oxide and water react in a combination reaction to rapidly release a large amount of heat, ensuring that the binder can heat up quickly and initially bond with the original pavement. Secondly, the reduced iron powder, carbon powder and sodium chloride react in a galvanic cell reaction to continuously release heat, so that the binder maintains fluidity for a long time and fills the gap between the paved asphalt blanket and the original pavement layer, improving the bonding performance between the two. Attached Figure Description

[0045] Figure 1 This is a flowchart of the design method of the present invention;

[0046] Figure 2 This is a structural diagram of the self-heating adhesive layer of the asphalt blanket in this invention;

[0047] Figure 3 This is a schematic diagram showing the relationship between the maximum heating temperature of the present invention and the experimental ratio of carbon powder to reduced iron powder;

[0048] Figure 4 This is a schematic diagram showing the relationship between the maximum heating temperature of the present invention and the experimental ratio of sodium chloride to reduced iron powder;

[0049] Figure 5 This is a schematic diagram showing the relationship between the mass change rate of the exothermic agent III of the present invention and the experimental ratio of calcium oxide to reduced iron powder.

[0050] In the diagram: 1—paved asphalt blanket, 2—adhesive, 3—heating agent. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1:

[0053] A method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets, wherein the self-heating adhesive layer for paved asphalt blankets is composed of an adhesive and a heating agent. The adhesive is composed of SBS modified asphalt and is distributed in layers on the lower surface of the paved asphalt blanket. The heating agent is composed of reduced iron powder, carbon powder, sodium chloride and calcium oxide uniformly mixed and randomly sprinkled on the lower surface of the adhesive.

[0054] The material composition ratio design method for the self-heating adhesive layer of the paved asphalt blanket includes the following steps:

[0055] Step 1: Design the experimental ratio of reduced iron powder, carbon powder, and sodium chloride in the heating agent:

[0056] A1: Design the experimental ratio of carbon powder to reduced iron powder: keep the amount of reduced iron powder constant, and uniformly select it within an initial molar ratio range of 0:1 to 1:1. Group The ratio was used as the experimental ratio of carbon powder and reduced iron powder. Appropriate amounts of carbon powder were added to each mixture, and after uniform mixing, exothermic agent I was obtained. Its highest heating temperature was then tested. The relationship between the highest heating temperature and the experimental ratio of carbon powder to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to carbon powder at which the curve reached its peak was obtained. ;

[0057] A2: Design the experimental ratio of sodium chloride and reduced iron powder: Use the same amount of reduced iron powder as in A1, add carbon powder according to the experimental ratio determined in A1, and uniformly select the powder within the initial molar ratio range of 0:1 to 2:1. Group The ratio was used as the experimental ratio of sodium chloride and reduced iron powder. Appropriate amounts of sodium chloride were added to each mixture, and after uniform mixing, exothermic agent II was obtained. Its maximum heating temperature was then tested. A curve showing the relationship between the highest heating temperature and the experimental ratio of sodium chloride to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to sodium chloride at which the curve reached its peak was obtained. ;

[0058] The chemical reactions occurring in heating agents I and II form a galvanic cell reaction with reduced iron powder as the positive electrode, carbon powder as the negative electrode, and sodium chloride solution as the electrolyte. The galvanic cell reaction includes a first-order reaction and a second-order reaction. After the reduced iron powder and carbon powder undergo the galvanic cell reaction, unstable ferric hydroxide is produced, which continues to react in a high-temperature environment to produce ferrous oxide and ferric oxide. The thermochemical equations for the first-order and second-order reactions are as follows:

[0059] First-order reaction:

[0060] Second-order reaction:

[0061] Step 2: Design the experimental proportion of calcium oxide in the heating agent and determine the optimal composition ratio of each material in the heating agent:

[0062] B1: Testing the maximum heating temperature under different calcium oxide dosages: Add the above materials according to the dosage of reduced iron powder in step one, and the experimental ratio of reduced iron powder to carbon powder and sodium chloride, and select them uniformly within the initial molar ratio range of 0:1 to 2:1. Group The ratio was used as the experimental ratio of calcium oxide to reduced iron powder. Appropriate amounts of calcium oxide were added to each mixture, and after uniform mixing, exothermic agent III was obtained. Its highest heating temperature was tested. Exothermic agent III underwent a galvanic cell reaction and a combination reaction, releasing heat. The thermochemical equation for the combination reaction is:

[0063]

[0064] B2: Prepare composite specimens according to the highest heating temperature of exothermic agent III: Heat multiple groups of equal amounts of binder to the highest heating temperature of exothermic agent III in B1, select the heating reaction product of exothermic agent III corresponding to this temperature, evenly sprinkle it on the surface of the above binder, and obtain a composite specimen composed of binder and heating reaction product after rolling treatment.

[0065] B3: Design the experimental ratio of calcium oxide to reduced iron powder: After immersing the composite specimen in water, calculate the corresponding mass change rate. A curve showing the relationship between the mass change rate of the composite specimen and the experimental ratio of calcium oxide to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to calcium oxide at which the curve reached its peak was obtained. The immersion treatment includes the following steps:

[0066] ① For composite specimens with different test ratios of calcium oxide and reduced iron powder, weigh their mass as follows: ;

[0067] ②Immerse the composite specimen in water for 24 hours, remove it, dry it, and weigh it. ;

[0068] ③ Calculate the rate of change of mass of the composite specimen: ;

[0069] B4: Calculate the mass ratio of each component of the heating agent: Based on the experimental ratios of reduced iron powder, carbon powder, sodium chloride, and calcium oxide in steps one and two (B3), calculate their mass fraction in the heating agent:

[0070]

[0071] In the formula: —Mass fraction (%) of each component in the heating agent; —The experimental proportions of each component material in the heating agent; —molar mass of each component material in the heating agent ( Of the parameters mentioned above, The materials referred to are reduced iron powder, carbon powder, sodium chloride, and calcium oxide, respectively.

[0072] Step 3: Calculate the unit calorific value of the heating agent:

[0073] Based on the composition ratio of the heating agent materials and the corresponding thermochemical reaction principles, the unit calorific value of the heating agent is calculated. :

[0074]

[0075] In the formula: —Heat output per unit of heating agent ; —The proportion of first-order reactions in the galvanic cell reaction; —The proportion of second-order reactions in the galvanic cell reaction; —The proportion of reduced iron powder in the heating agent (%); —The percentage of calcium oxide in the heating agent (%) —Enthalpy change of first-order reactions ; —Enthalpy change of second-order reaction ; —Enthalpy change of combination reactions ;

[0076] The specific calculation process for the unit calorific value Q of the heating agent is as follows:

[0077] The thermochemical equation for the chemical reaction of the heating agent material:

[0078]

[0079]

[0080]

[0081] In the formula: —The solid state in which matter exists; —Gas in the state of matter; —Liquid in the state of matter;

[0082] And the mass fraction of each material in the heating agent: % Reduced iron powder, % activated carbon, % sodium chloride, % calcium oxide;

[0083] Assuming the unit of the heating agent is 100 grams, then the composition of the heating agent material is as follows: Reduced iron powder, gram of activated carbon, Sodium chloride, 100 grams of calcium oxide, at this point the amount of reduced iron powder is: The amount of calcium oxide is ;

[0084] The calorific value of reduced iron powder is divided into two parts:

[0085] in:

[0086] First-order reaction:

[0087] Second-order reaction:

[0088] The calorific value of calcium oxide is:

[0089]

[0090] Therefore, when the amount of heating agent is 1 unit, the unit heat output is... :

[0091]

[0092] That is, the unit heat output of the heating agent :

[0093]

[0094] The proportion of the first-order reaction in the galvanic cell reaction. The specific calculation process is as follows:

[0095] The chemical equation for the reaction occurring in a primary galvanic cell is as follows:

[0096] ① The reaction mass increased by 16 grams.

[0097] ② The reaction mass increased by 24 grams.

[0098] Let the mass of the reduced iron powder be m, and the mass difference before and after the reaction be... Let the mass of reduced iron powder consumed in reaction ① account for... In step ②, the mass of reduced iron powder consumed in the reaction accounts for b%, and there is... ;

[0099] The reduced iron powder reacts in ① The reaction in ② ;

[0100] Therefore, ① the mass difference in the reaction:

[0101]

[0102] ②Mass difference in the reaction:

[0103]

[0104]

[0105] Then we have:

[0106] ;

[0107] The proportion of the second-order reaction in the galvanic cell reaction in step three. for:

[0108]

[0109] Step 4: Calculate the ratio of heating agent to binder;

[0110] Based on the heat transfer characteristics between layers and the unit heat output of the heating agent in step three, the ratio of heating agent to binder is calculated. :

[0111]

[0112] In the formula: —The ratio of heating agent to binder; —Specific heat capacity of adhesive ; —Temperature difference of the binder before and after the heating agent ignites ; — Thermal conductivity of the adhesive ; —The thermal conductivity of the original road surface ;

[0113] The calculation of the ratio of the heating agent to the binder is derived as follows;

[0114] Assume the amount of adhesive used is The adhesive will heat up The amount of calories required is :

[0115]

[0116] Based on the thermal conductivity of the adhesive and the original road surface and The heat generated by the heating agent is used to heat the binder, which is then determined to be... :

[0117]

[0118] When the amount of heating agent used is 1 unit, the calorific value of the heating agent in step three will be... Substituting into the above equation, we get:

[0119]

[0120] The amount of adhesive used is:

[0121]

[0122] Therefore, the ratio of heating agent to binder under this condition can be calculated. :

[0123]

[0124] Example 2:

[0125] Step 1: Design the experimental ratio of reduced iron powder, carbon powder, and sodium chloride in the heating agent:

[0126] A1: Design the experimental ratio of carbon powder to reduced iron powder in the heating agent: Take Five ratios (0:1, 0.3:1, 0.5:1, 0.8:1, and 1:1) were selected within an initial molar ratio range of 0:1 to 1:1 as experimental ratios, i.e., 0 grams, 0.3 grams, and 0.8 grams of carbon powder were added respectively. 0.5 grams 0.8 grams gram, After uniform mixing, exothermic agent I was obtained. Its maximum exothermic temperature was tested, and a curve showing the relationship between the maximum exothermic temperature and the experimental ratio of carbon powder to reduced iron powder was plotted. Figure 3 As shown, the experimental ratio of reduced iron powder to carbon powder was obtained when the curve reached its peak. ;

[0127] A2: Design the experimental ratio of sodium chloride to reduced iron powder in the heating agent: Take Reduce iron powder by adding carbon powder according to the experimental ratio determined in A1. Five ratios (0:1, 0.5:1, 1:1, 1.5:1, and 2:1) were selected within an initial molar ratio range of 0:1 to 2:1 as experimental ratios, i.e., 0 grams, 0.5 grams, and 2.5 grams of sodium chloride were added respectively. gram, 1.5 grams gram, 2 After uniform mixing, gram of sodium chloride and reduced iron powder were used to obtain exothermic agent II. Its maximum exothermic temperature was tested, and a curve showing the relationship between the maximum exothermic temperature and the experimental ratio of sodium chloride to reduced iron powder was plotted. Figure 4 As shown, the experimental ratio of reduced iron powder to sodium chloride at which the peak value was obtained was obtained. ;

[0128] Step 2: Design the experimental proportion of calcium oxide in the heating agent and determine the optimal composition ratio of each material in the heating agent:

[0129] B1: Test the highest heating temperature when using different amounts of calcium chloride: Take Reduced iron powder, and add carbon powder and sodium chloride according to the experimental ratio determined in A1. Kehe Five ratios (0:1, 0.5:1, 1:1, 1.5:1, and 2:1) were selected within an initial molar ratio range of 0:1 to 2:1 as experimental ratios, i.e., 0 g, 0.5 g, and 2:1 g of calcium oxide were added respectively. gram, 1.5 grams gram, 2 1 gram, after being uniformly mixed, to obtain heating agent III, and its highest heating temperature was tested;

[0130] B2: Prepare composite specimens according to the highest heating temperature of exothermic agent III: Heat multiple groups of equal amounts of binder to the highest heating temperature of exothermic agent III in B1, select the heating reaction product of exothermic agent III corresponding to this temperature, evenly sprinkle it on the surface of the above binder, and obtain a composite specimen composed of binder and heating reaction product after rolling treatment.

[0131] B3: Design the experimental ratio of calcium oxide to reduced iron powder: Weigh the composite specimens with different experimental ratios of calcium oxide to reduced iron powder in B2 and record the weight as follows. The composite specimens were immersed in water for 24 hours, then removed, dried, and weighed. Calculate the corresponding rate of change in mass. And plot the relationship curve between the mass change rate of the composite specimen and the experimental ratio of calcium oxide to reduced iron powder, such as Figure 5 As shown, the experimental ratio of reduced iron powder to calcium oxide was obtained when the curve reached its peak. ;

[0132] B4: Calculate the mass ratio of each component of the heating agent: Combining steps one and two (B3), calculate the experimental ratio of reduced iron powder: carbon powder: sodium chloride: calcium oxide. Calculate the mass fraction of each component in the heating agent:

[0133]

[0134]

[0135]

[0136]

[0137] Step 3: Calculate the unit calorific value of the heating agent:

[0138] Based on the composition ratio of the heating agent materials and the corresponding thermochemical reaction principles, the unit calorific value of the heating agent is calculated. :

[0139]

[0140] Step 4: Calculate the ratio of heating agent to binder;

[0141] Based on the heat transfer characteristics between layers and the unit heat output of the heating agent in step three, the ratio of heating agent to binder is calculated. :

[0142] .

[0143] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for designing the material composition ratio of a self-heating adhesive layer for paved asphalt blankets, characterized in that, The self-heating adhesive layer of the paved asphalt blanket is composed of an adhesive and a heating agent. The adhesive is made of SBS modified asphalt and is distributed in layers on the lower surface of the paved asphalt blanket. The heating agent is a uniform mixture of reduced iron powder, carbon powder, sodium chloride and calcium oxide, and is randomly sprinkled on the lower surface of the adhesive. The material composition ratio design method for the self-heating adhesive layer of the paved asphalt blanket includes the following steps: Step 1: Design the experimental ratio of reduced iron powder, carbon powder, and sodium chloride in the heating agent: A1: Design the experimental ratio of carbon powder to reduced iron powder: keep the amount of reduced iron powder constant, and uniformly select it within the initial molar ratio range of 0:1 to 1:

1. The ratio was used as the experimental ratio of carbon powder and reduced iron powder. Appropriate amounts of carbon powder were added to each mixture, and after uniform mixing, exothermic agent I was obtained. Its highest heating temperature was then tested. The relationship between the highest heating temperature and the experimental ratio of carbon powder to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to carbon powder at which the curve reached its peak was obtained. ; A2: Design the experimental ratio of sodium chloride and reduced iron powder: Use the same amount of reduced iron powder as in A1, add carbon powder according to the experimental ratio determined in A1, and uniformly select the powder within the initial molar ratio range of 0:1 to 2:

1. The ratio was used as the experimental ratio of sodium chloride and reduced iron powder. Appropriate amounts of sodium chloride were added to each mixture, and after uniform mixing, exothermic agent II was obtained. Its maximum heating temperature was then tested. A curve showing the relationship between the highest heating temperature and the experimental ratio of sodium chloride to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to sodium chloride at which the curve reached its peak was obtained. ; Step 2: Design the experimental proportion of calcium oxide in the heating agent and determine the optimal composition ratio of each material in the heating agent: B1: Testing the maximum heating temperature under different calcium oxide dosages: Add the above materials according to the dosage of reduced iron powder in step one, and the experimental ratio of reduced iron powder to carbon powder and sodium chloride, and select them uniformly within the initial molar ratio range of 0:1 to 2:

1. The ratio was used as the experimental ratio of calcium oxide and reduced iron powder. Appropriate amounts of calcium oxide were added to each, and after uniform mixing, exothermic agent III was obtained, and its maximum exothermic temperature was tested. B2: Prepare composite specimens according to the highest heating temperature of exothermic agent III: Heat multiple groups of equal amounts of binder to the highest heating temperature of exothermic agent III in B1, select the heating reaction product of exothermic agent III corresponding to this temperature, evenly sprinkle it on the surface of the above binder, and obtain a composite specimen composed of binder and heating reaction product after rolling treatment. B3: Design the experimental ratio of calcium oxide to reduced iron powder: After immersing the composite specimen in water, calculate the corresponding mass change rate. A curve showing the relationship between the mass change rate of the composite specimen and the experimental ratio of calcium oxide to reduced iron powder was plotted, and the experimental ratio of reduced iron powder to calcium oxide at which the curve reached its peak was obtained. ; B4: Calculate the mass ratio of each component in the heating agent: Based on the experimental ratios of reduced iron powder, carbon powder, sodium chloride, and calcium oxide in steps one and two (B3), calculate their mass fraction in the heating agent: ； In the formula: —Mass fraction (%) of each component in the heating agent; —The experimental proportions of each component material in the heating agent; —molar mass of each component material in the heating agent ( Of the parameters mentioned above, The materials referred to are reduced iron powder, carbon powder, sodium chloride, and calcium oxide, respectively. Step 3: Calculate the unit calorific value of the heating agent: Based on the composition ratio of the heating agent materials and the corresponding thermochemical reaction principles, the unit calorific value of the heating agent is calculated. : ； The thermochemical reactions that occur in the heating agent material include the following three thermochemical reaction equations: The first-order reaction in a galvanic cell: ; Second-order reaction in a galvanic cell: ; Combination reaction: ; In the formula: —Heat output per unit of heating agent ; —The proportion of first-order reactions in the galvanic cell reaction; —The proportion of second-order reactions in the galvanic cell reaction; —The proportion of reduced iron powder in the heating agent (%); —The percentage of calcium oxide in the heating agent (%) —Enthalpy change of first-order reactions ; —Enthalpy change of second-order reaction ; —Enthalpy change of combination reactions ; Step 4: Calculate the ratio of heating agent to binder; Based on the heat transfer characteristics between layers and the unit heat output of the heating agent in step three, the ratio of heating agent to binder is calculated. : ； In the formula: —The ratio of heating agent to binder; —Specific heat capacity of adhesive ; —Temperature difference of the binder before and after the heating agent ignites ; — Thermal conductivity of the adhesive ; —The thermal conductivity of the original road surface .

2. The material composition ratio design method for a self-heating adhesive layer of paved asphalt blanket according to claim 1, characterized in that, The chemical reactions of the heating agent material in steps one and two (B1) include galvanic cell reactions and combination reactions. The galvanic cell reaction is a redox reaction that occurs with reduced iron powder as the positive electrode, carbon powder as the negative electrode, and sodium chloride solution as the electrolyte solution. It includes first-order and second-order reactions. After the reduced iron powder and carbon powder undergo a galvanic cell reaction, unstable ferric hydroxide is produced, which continues to react in a high-temperature environment to produce ferrous oxide and ferric oxide.

3. The material composition ratio design method for a self-heating adhesive layer of paved asphalt blanket according to claim 1, characterized in that, The specific steps for immersing the composite specimen in step B3 are as follows: ① For composite specimens with different test ratios of calcium oxide and reduced iron powder, weigh their mass as follows: ; ②Immerse the composite specimen in water for 24 hours, remove it, dry it, and weigh it. ; ③ Calculate the rate of change of mass of the composite specimen: .

4. The material composition ratio design method for a self-heating adhesive layer of paved asphalt blanket according to claim 1, characterized in that, The proportion of the first-order reaction in the galvanic cell reaction in step three. for: ； In the formula: —The mass (g) of reduced iron powder in the exothermic agent; —The mass difference (g) of the exothermic agent before and after the reaction; The proportion of the second-order reaction in the galvanic cell reaction in step three. for: 。

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