METHOD FOR EVALUATING AND UTILIZING SONNENBRAND BASALT AGGREGATE

Abstract

Provided is a method for evaluating and utilizing sonnenbrand basalt aggregate, including steps as follows: mixing a basalt aggregate defined as sonnenbrand basalt into an asphalt mixture; carrying out thermal aging experiments at different temperatures and durations to obtain a theoretical trigger time t.sub.i for the sonnenbrand phenomenon under a thermal aging temperature T.sub.i; further calculating to obtain a theoretical thermal aging factor AF.sub.0 for the sonnenbrand phenomenon; statistically calculating a thermal aging factor AF for an actual construction to evaluate a performance of the basalt aggregate, if AF<AF.sub.0, the construction may be carried out normally, if AF≥AF.sub.0, then shortening the transportation and waiting duration and/or lowering the factory temperature of the asphalt mix so that the thermal aging factor AF<AF.sub.0 during actual construction.

Claims

1. A method for evaluating and utilizing a sonnenbrand basalt aggregate, comprising following steps: (1) mixing a basalt aggregate defined as a sonnenbrand basalt into an asphalt mixture, wherein, a. mixing the basalt aggregate into an asphalt mixture; b. subjecting the asphalt mixture to thermal aging under a temperature condition of 180 degrees Celsius for 5 hours; c. cooling the asphalt mixture after finishing the thermal aging to a room temperature, then adding water of room temperature into the asphalt mixture until the asphalt mixture is submerged; and d. standing for 24 hours, taking out the aggregate bonded into lumps out of the water, and gently breaking off by hand to observe whether there is an asphalt coating peeling phenomenon in an appearance of the aggregate, and determining whether the basalt aggregate is a sonnenbrand basalt according to observed results; (2) carrying out experiments on several proportions of the asphalt mixture prepared in the step (1) under conditions of different thermal aging temperatures and different thermal aging durations, wherein the experiments are arranged with several groups, and the thermal aging temperatures of the experiments arranged with the several groups are in a value range of 150 degrees Celsius-190 degrees Celsius and are selected at equal intervals within the value range of the temperatures, denoted as T1, i=1, 2 . . . , n, and n is a number of experimental groups; in each group of the experiments, a thermal aging duration of each of the experiments is in a value range of 0 hour-12 hours, and is selected respectively at equal intervals within the value range; shaping the asphalt mixture after thermal aging into a Marshall specimen, measuring the specimen in terms of Cantabro raveling loss, and determining a theoretical spot trigger time ti respectively under different thermal aging temperatures Ti according to a relationship curve of thermal aging duration-raveling loss obtained from each group of experiments; wherein a method for determining the theoretical spot trigger time ti is: when a raveling loss corresponding to an inflection point of a significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is ≤15%, the thermal aging duration corresponding to the inflection point is the theoretical spot trigger time ti; and when the raveling loss corresponding to the inflection point of the significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is >15%, the thermal aging duration corresponding to the raveling loss of 15% is the theoretical spot trigger time ti; (3) determining a theoretical thermal aging factor AFi of a sonnenbrand basalt aggregate obtained from each group of experiments according to a calculation method:
AFi=Ti×ti wherein AFi is a theoretical thermal aging factor obtained from an ith group experiment, i=1, 2 . . . , n, and n is a number of experimental groups; a minimum value of AFi is taken as a theoretical thermal aging factor AF0 of a sonnenbrand phenomenon:
AF0=min{AF_1 . . . AF_i . . . AF_n} (4) calculating a thermal aging factor AF of an actual construction:
AF=T′×t′ wherein T′ is an average temperature value of a factory temperature of the actual construction of the asphalt mixture when a material truck leaves a mixing plant and an arrival temperature of the material truck after reaching a site and starting to pave, and t′ is a duration for transportation and waiting for the material truck of the asphalt mixture from leaving a mixing plant to arriving at the site to start paving; and (5) evaluating the basalt aggregate in terms of performance, carrying out a construction normally if AF<AF0 when the basalt aggregate is used to pave an upper layer, and shortening the duration for transportation and waiting and lowering the factory temperature of the asphalt mixture if AF≥AF0 to make the thermal aging factor of the actual construction AF<AF0; and when the basalt aggregate is used to pave other surface layers below the upper layer, carrying out a construction normally if AF<AF0; and if AF≥AF0, shortening the duration for transportation and waiting and/or lowering the factory temperature of the asphalt mixture to make the thermal aging factor of the actual construction AF<AF0, or adding a waterproof insulation layer above the surface layer.

2. (canceled)

3. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 1, wherein as observing whether there is the asphalt coating peeling phenomenon on the appearance of the aggregate, the asphalt coating peeling phenomenon is graded according to a peeling situation of the asphalt coating, with a grading criteria of: grade 5: the asphalt coating is completely preserved, with a percentage of a peeled area close to 0; grade 4: the asphalt coating is moved by water in a few portions with an uneven thickness, and the percentage of peeled area is less than or equal to 10%; grade 3: the asphalt coating is obviously moved by water locally, basically retained on a surface of the aggregate, and the percentage of peeled area is less than or equal to 30%; grade 2: the asphalt coating is largely moved by water, partially remained on the surface of aggregate, and the percentage of the peeled area is greater than 30%; and grade 1: the asphalt coating is completely moved by water, the aggregate is basically exposed, and the asphalt floats on a water surface; the basalt aggregate is defined as a sonnenbrand basalt if the grade is below 5.

4. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 1, wherein in the step (1), when mixing the basalt aggregate defined as sonnenbrand basalt into the asphalt mixture, a production mixture ratio adopted in actual construction is used for mixing.

5. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 4, wherein the asphalt mixture mixed in the step (1) is any one of asphalt concrete (AC) mixture, stone matrix asphalt (SMA), open-graded friction course (OGFC) porous asphalt mixture or porous asphalt concrete (PAC) asphalt mixture.

6. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 5, wherein in the step (5), as lowering the factory temperature of the asphalt mixture, the factory temperature of the asphalt mixture is lowered by using a warm-mixing technology.

7. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 6, wherein the waterproof insulation layer comprises a double-layer structure of a waterproof layer and a thermal insulation layer.

8. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 7, wherein the waterproof layer is any one of emulsified asphalt, hot asphalt, hot asphalt macadam sealing layer and polymer material paving layer.

9. The method for evaluating and utilizing sonnenbrand basalt aggregate according to claim 8, wherein the insulation layer is any one of material laying layers such as rubber, ceramic, rock wool, fiber, foam board.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 shows a relationship diagram of thermal aging duration-raveling loss obtained from thermal aging experiments on a described porous asphalt concrete (PAC) asphalt mixture for different durations at the thermal aging temperature of 180 degrees Celsius (° C.) as described in the present application.

[0036] FIG. 2 shows a relationship diagram of thermal aging duration-raveling loss obtained from thermal aging experiments on a described stone matrix asphalt (SMA) asphalt mixture for different durations at the thermal aging temperature of 190° C. as described in the present application.

[0037] FIG. 3 illustrates a process of a method for evaluating and utilizing a sonnenbrand basalt aggregate according to an embodiment of the present application.

[0038] FIG. 4 shows a process of a method for defining a basalt aggregate according to an embodiment of the present application.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The present application provides a method for evaluating and utilizing a sonnenbrand basalt aggregate, including the following steps as shown in FIG. 3: [0040] S1, mixing a basalt aggregate defined as a sonnenbrand basalt into an asphalt mixture; [0041] S2, carrying out experiments on several proportions of the asphalt mixture prepared in the S1 under conditions of different thermal aging temperatures and different thermal aging durations, where the experiments are arranged with several groups, and the thermal aging temperatures of the experiments arranged with several groups are in a value range of 150 degrees Celsius (° C.)-190° C. and are selected at equal intervals within the value range of the temperatures, denoted as T.sub.1, i=1, 2 . . . , n, and n is a number of experimental groups; in each group of the experiments, a thermal aging duration of each experiment is in a value range of 0 hour (h)-12 h, and is selected respectively at equal intervals within the value range; shaping the asphalt mixture after thermal aging into a Marshall specimen, measuring the specimen in terms of Cantabro raveling loss, and determining a theoretical spot trigger time t.sub.i, respectively under different thermal aging temperatures T, according to a relationship curve of thermal aging duration-raveling loss obtained from each group of experiments; [0042] S3, determining a theoretical thermal aging factor AF.sub.0, of the basalt aggregate defined as the sonnenbrand basalt obtained from each group of experiments according to a calculation method as follows:

AF.sub.i=T.sub.i×t.sub.i [0043] among them, AF.sub.i is a theoretical thermal aging factor obtained from an i.sup.th group experiment, i=1, 2 . . . , n, and n is the number of experimental groups; a minimum value of AF.sub.i is taken as a theoretical thermal aging factor AF.sub.0 of the sonnenbrand phenomenon, where:

AF.sub.0=min{AF.sub.1 . . . AF.sub.i . . . AF.sub.n}; [0044] S4, calculating a thermal aging factor AF of an actual construction:

AF=T′×t′; [0045] among them, T′ is an average temperature value of a factory temperature of the actual construction of the asphalt mixture when a material truck leaves a mixing plant and an arrival temperature of the material truck after reaching a site and starting to pave, and t′ is a duration for transportation and waiting for the material truck of the asphalt mixture from leaving a factory to arriving at the site to start paving; [0046] S5, evaluating the basalt aggregate in terms of performance, carrying out a construction normally if AF<AF.sub.0 when the basalt aggregate is used to pave an upper layer, and shortening the duration for transportation and waiting and lowering the factory temperature of the asphalt mixture if AF≥AF.sub.0 to make the thermal aging factor of the actual construction AF<AF.sub.0; and [0047] when the basalt aggregate is used to pave other surface layers below the upper layer, carrying out a construction normally if AF<AF.sub.0; and if AF≥AF.sub.0, shortening the duration for transportation and waiting and/or lowering the factory temperature of the asphalt mixture to make the thermal aging factor of the actual construction AF<AF.sub.0, or adding a waterproof insulation layer above the surface layer.

Embodiment 1

[0048] This embodiment provides a method for evaluating and utilizing a sonnenbrand basalt aggregate, which specifically includes the following steps: [0049] (1) porous asphalt concrete (PAC) asphalt mixture is used in this embodiment; before construction, the basalt aggregate is defined with the following defining method as shown in FIG. 4: [0050] a. mixing PAC with an oil-to-rock ratio of 4.9% and 0.1% polyester fiber incorporated in accordance with the PAC-13 production ratio (see Table 1) actually used in constructions;

TABLE-US-00001 TABLE 1 Gradation of PAC asphalt mixture Mass passage rate of passing through the following sieve holes (mm)/% Mixture type 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 PAC-13 100 89.1 55.9 15.5 12.5 8.2 6.7 6.0 5.4 4.0 [0051] b. evenly dispersing the asphalt mixture obtained by mixing in a tray, and placing the tray in an oven at 180° C. for thermal aging for 5 h; [0052] c. taking the tray out of the oven, cooling the asphalt mixture to room temperature, and adding water of room temperature into the tray until the mixture is submerged; and [0053] d. standing the asphalt mixture for 24 hours (h), then taking out the aggregate bonded together into lumps from the tray, and breaking them lightly by hand to observe whether there is asphalt coating peeling phenomenon in the aggregate appearance, and determining that the basalt aggregate is sonnenbrand basalt when there is peeling phenomenon. In this embodiment, the asphalt coating peeling phenomenon is graded according to the asphalt coating peeling situation as observing whether there is asphalt coating peeling phenomenon in the aggregate appearance, see Table 2 for the grading standard.

TABLE-US-00002 TABLE 2 Grade of asphalt coating peeling Adhesion Asphalt peeling on aggregate surface after test grade The asphalt coating is completely preserved, with a 5 percentage of a peeled area close to 0. The asphalt coating is moved by water in a few portions 4 with an uneven thickness, and the percentage of peeled area is less than or equal to 10%. The asphalt coating is obviously moved by water locally, 3 basically retained on a surface of the aggregate, and the percentage of peeled area is less than or equal to 30%. The asphalt coating is largely moved by water, partially 2 remained on the surface of aggregate, and the percentage of the peeled area is greater than 30%. The asphalt coating is completely moved by water, the 1 aggregate is basically exposed, and the asphalt floats on the water surface.

[0054] For observation, the percentage of peeled area is visually measured by two or more testers respectively, and the average value is taken as the test result; when the grade obtained from the test results is lower than grade 5, i.e., when the grade is determined to be 1-4, the basalt aggregate is judged to be a sonnenbrand basalt. The PAC asphalt mixture formulated in this embodiment has a severely peeled appearance of grade 2 and is diagnosed as a sonnenbrand basalt; [0055] the PAC asphalt mixture of sonnenbrand basalt is still prepared according to the ratio in Table 1; [0056] (2) part of the asphalt mixture to be used, prepared in step (1), is taken for experiments under different thermal aging temperatures and different thermal aging durations; in this embodiment, the experiments include 5 groups, and the thermal aging temperatures of the 5 groups of experiments are in the value range of 150° C.-190° C., which are selected at equal intervals within the value range, and are recorded as T.sub.i, i=1, 2 . . . , 5; in this embodiment, T.sub.1=150° C., T.sub.2=160° C., T.sub.3=170° C., T.sub.4=180° C., T.sub.5=190° C.; in each of the 5 groups of experiments, the value range of the thermal aging duration of each experiment is 0 h-12 h, which are selected at equal intervals within the value range of duration, and in this implementation, the thermal aging duration is set to 0 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 12 h, i.e., each group of experiments includes 8 experiments.

[0057] The asphalt mixture after thermal aging is molded into a Marshall specimen, and the Cantabro raveling loss of the specimen is tested, so as to obtain the relationship curves of thermal aging duration-raveling loss under different thermal aging temperatures T.sub.i, respectively, and the theoretical spot triggering time t.sub.i is determined according to the curves, with a specific determination method as follows: when a raveling loss corresponding to an inflection point of a significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is ≤15%, the thermal aging duration corresponding to the inflection point is the theoretical spot trigger time t.sub.i; and when the raveling loss corresponding to the inflection point of the significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is >15%, the thermal aging duration corresponding to the raveling loss of 15% is the theoretical spot trigger time t.sub.i; [0058] (3) the theoretical thermal aging factor AF.sub.i of the sonnenbrand basalt aggregate obtained from each group of experiments is calculated, and the calculation method is as follows:

AF.sub.i=T.sub.i×t.sub.i [0059] among them, AF.sub.0, is the theoretical thermal aging factor obtained from group i experiments, and i=1, 2 . . . , 5; the minimum value of AF.sub.0, is taken as the theoretical thermal aging factor AF.sub.0 of the basalt phenomenon, where:

AF.sub.0=min{AF.sub.1 . . . AF.sub.i . . . AF.sub.n} [0060] in this embodiment, the minimum value of AFi is obtained from the fourth group of experiments, and the thermal aging duration-raveling loss relationship diagram of the fourth group of experiments is shown in FIG. 1; the theoretical triggering time t.sub.4 of the sonnenbrand phenomenon in the fourth group of experiments is 5 h, and the corresponding raveling loss of asphalt mixture is 14.1%, less than 15%. In this embodiment, AF.sub.0 is as follows:

AF.sub.0=AF.sub.4=T.sub.4×t.sub.4=180° C.×5 h=900° C..Math.h [0061] (4) the thermal aging factor of actual construction AF is calculated as:

AF=T′×t′ [0062] among them, T′ is an average temperature value of a factory temperature of the actual construction of the asphalt mixture when a material truck leaves a mixing plant and an arrival temperature of the material truck after reaching a site and starting to pave, and t′ is a duration for transportation and waiting for the material truck of the asphalt mixture from leaving a mixing plant to arriving at the site to start paving; [0063] statistics of the transportation and waiting duration t′ of a material truck of PAC asphalt mixture for a physical project is 6 h, the average value of factory temperature T.sub.1 when driving out of the mixing plant is 182° C., and the average value of arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 178° C.; the thermal aging factor AF=(178+182)×6/2=1080° C..Math.h is calculated for the actual construction; [0064] (5) in this embodiment, the thermal aging factor in actual construction is AF>AF.sub.0; the raveling loss of PAC asphalt mixture taken from the pavement site and tested by forming Marshall specimens indoors is 21.6%, the standard raveling loss of PAC asphalt mixture ≯15%, which indicates that the raveling loss of asphalt mixture has exceeded the standard, the road performance is significantly deteriorated and cannot be used directly.

[0065] To overcome the sonnenbrand phenomenon, the present embodiment reduces the production temperature of PAC asphalt mixture by mixing warm mixer. The amount of warm mixer blended in this embodiment is 5 weight percentage (wt %) of the asphalt mixture mass, so that the factory temperature T.sub.1 when driving out of the mixing plant is 162° C. on average, and the arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 156° C. on average. In addition, the construction organization is optimized to shorten the engaging duration of construction, shorten the transportation and waiting duration t′ to 5 h, and the thermal aging factor of the actual construction is calculated as AF=(156+162)×5/2=795° C..Math.h, AF<AF.sub.0. The optimized PAC asphalt mixture is taken from the pavement site and tested again by forming Marshall specimens indoors, with a raveling loss of 11.8%, in compliance with the standard raveling loss of PAC asphalt mixture ≯15%, indicating that the pavement performance of the asphalt mixture has been significantly improved, and the sonnenbrand basalt is used according to the improved construction method.

Embodiment 2

[0066] The basalt aggregate and asphalt mixture used in this embodiment are exactly the same as in Embodiment 1, and steps (1)-(3) are the same as in Embodiment 1. In step (4) of the present embodiment, statistics of the transportation and waiting duration t′ of a material truck of PAC asphalt mixture for a physical project is about 2 h, the average value of factory temperature T.sub.1 when driving out of the mixing plant is 180° C., and the average value of arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 178° C.; the thermal aging factor AF=(178+180)×2/2=358° C..Math.h is calculated for the actual construction.

[0067] The thermal aging factor in actual construction is AF<AF.sub.0; the raveling loss of PAC asphalt mixture taken from the pavement site and tested by forming Marshall specimens indoors is 11.2%, which is lower than the standard raveling loss of PAC asphalt mixture ≯15% and comparable to the raveling loss of fresh PAC asphalt mixture, indicating that the pavement performance of the asphalt mixture has no significant degradation and the light spot basalt may be used according to the existing construction method.

Embodiment 3

[0068] This embodiment provides a method for evaluating and utilizing sonnenbrand basalt aggregate, which specifically includes the following steps: [0069] stone matrix asphalt (SMA) asphalt mixture is used in this embodiment; before construction, the basalt aggregate is defined with the following defining method: [0070] a. mixing SMA with an oil-to-rock ratio of 6.0% and 0.3% lignin fiber incorporated in accordance with the SMA-13 production ratio (see Table 3) actually used in constructions;

TABLE-US-00003 TABLE 3 Gradation of SMA asphalt mixture Mass passage rate of passing through the following sieve holes (mm)/% Mixture type 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 SMA-13 100 94.7 63.5 27.1 19.6 16.6 14.0 12.5 11.7 10.5 [0071] b. evenly dispersing the asphalt mixture obtained by mixing in a tray, and placing the tray in an oven at 180° C. for thermal aging for 5 h; [0072] c. taking the tray out of the oven, cooling the asphalt mixture to room temperature, and adding water of room temperature into the tray until the mixture is submerged; and [0073] d. standing the asphalt mixture for 24 hours (h), then taking out the aggregate bonded together into lumps from the tray, and breaking them lightly by hand to observe whether there is asphalt coating peeling phenomenon in the aggregate appearance, and determining that the basalt aggregate is sonnenbrand basalt when there is peeling phenomenon. In this embodiment, the asphalt coating peeling phenomenon is graded according to the asphalt coating peeling situation as observing whether there is asphalt coating peeling phenomenon in the aggregate appearance, see Table 4 for the grading standard.

TABLE-US-00004 TABLE 4 Grade of asphalt coating peeling Adhesion Asphalt peeling on aggregate surface after test grade The asphalt coating is completely preserved, with a 5 percentage of a peeled area close to 0. The asphalt coating is moved by water in a few portions 4 with an uneven thickness, and the percentage of peeled area is less than or equal to 10%. The asphalt coating is obviously moved by water locally, 3 basically retained on a surface of the aggregate, and the percentage of peeled area is less than or equal to 30%. The asphalt coating is largely moved by water, partially 2 remained on the surface of aggregate, and the percentage of the peeled area is greater than 30%. The asphalt coating is completely moved by water, the 1 aggregate is basically exposed, and the asphalt floats on the water surface.

[0074] For observation, the percentage of peeled area is visually measured by two or more testers respectively, and the average value is taken as the test result; when the grade obtained from the test results is lower than grade 5, i.e., when the grade is determined to be 1-4, the basalt aggregate is judged to be a sonnenbrand basalt. The SMA asphalt mixture formulated in this embodiment has a severely peeled appearance of grade 3 and is diagnosed as a sonnenbrand basalt; [0075] the SMA asphalt mixture of sonnenbrand basalt is still prepared according to the ratio in Table 1; [0076] part of the asphalt mixture to be used, prepared in step (1), is taken for experiments under different thermal aging temperatures and different thermal aging durations; in this embodiment, the experiments include 5 groups, and the thermal aging temperatures of the 5 groups of experiments are in the value range of 150° C.-190° C., which are selected at equal intervals within the value range, and are recorded as T.sub.i, i=1, 2 . . . , 5; in this embodiment, T.sub.1=150° C., T.sub.2=160° C., T.sub.3=170° C., T.sub.4=180° C., T.sub.5=190° C.; in each of the 5 groups of experiments, the value range of the thermal aging duration of each experiment is 0 h-12 h, which are selected at equal intervals within the value range of duration, and in this implementation, the thermal aging duration is set to 0 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 12 h, i.e., each group of experiments includes 8 experiments.

[0077] The asphalt mixture after thermal aging is molded into a Marshall specimen, and the Cantabro raveling loss of the specimen is tested, so as to obtain the relationship curves of thermal aging duration-raveling loss under different thermal aging temperatures T.sub.i, respectively, and the theoretical spot triggering time t.sub.i is determined according to the curves, with a specific determination method as follows: when a raveling loss corresponding to an inflection point of a significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is ≤15%, the thermal aging duration corresponding to the inflection point is the theoretical spot trigger time t.sub.i; and when the raveling loss corresponding to the inflection point of the significantly increased raveling loss in the relationship curve of the thermal aging duration-raveling loss is >15%, the thermal aging duration corresponding to the raveling loss of 15% is the theoretical spot trigger time t.sub.i [0078] (3) the theoretical thermal aging factor AF.sub.0, of the sonnenbrand basalt aggregate obtained from each group of experiments is calculated, and the calculation method is as follows:

AF.sub.i=T.sub.i×t.sub.i [0079] among them, AF.sub.0, is the theoretical thermal aging factor obtained from group i experiments, and i=1, 2 . . . , 5; the minimum value of AF.sub.i is taken as the theoretical thermal aging factor AF.sub.0 of the basalt phenomenon, where:

AF.sub.0=min{AF.sub.1 . . . AF.sub.i . . . AF.sub.n} [0080] in this embodiment, the minimum value of AF.sub.i is obtained from the fifth group of experiments, and the thermal aging duration-raveling loss relationship diagram of the fifth group of experiments is shown in FIG. 2; the theoretical triggering time t.sub.5 of the sonnenbrand phenomenon in the fifth group of experiments is 6 h, and the corresponding raveling loss of asphalt mixture is 13.5%, less than 15%. In this embodiment, AF.sub.0 is as follows:

AF.sub.0=AF.sub.5=T.sub.5×t.sub.5=190° C.×6 h=1140° C..Math.h [0081] (4) the thermal aging factor of actual construction AF is calculated as:

AF=T′×t′ [0082] among them, T′ is an average temperature value of a factory temperature of the actual construction of the asphalt mixture when a material truck leaves a mixing plant and an arrival temperature of the material truck after reaching a site and starting to pave, and t′ is a duration for transportation and waiting for the material truck of the asphalt mixture from the mixing plant to the site to start paving; [0083] statistics of the transportation and waiting duration t′ of a material truck of SMA asphalt mixture for a physical project is 6 h, the average value of factory temperature T.sub.1 when driving out of the mixing plant is 180° C., and the average value of arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 174° C.; the thermal aging factor AF=(180+174)×6/2=1062° C..Math.h is calculated for the actual construction; [0084] (5) in this embodiment, the thermal aging factor in actual construction is AF<AF.sub.0; the raveling loss of SMA asphalt mixture taken from the pavement site and tested by forming Marshall specimens indoors is 13.5%, the standard raveling loss of SMA asphalt mixture ≯15%, which indicates that the raveling loss of asphalt mixture has not exceeded the standard, there is no significant deterioration of the road performance and can be used directly.

Embodiment 4

[0085] The basalt aggregate and asphalt mixture used in this embodiment are exactly the same as in Embodiment 3, and steps (1)-(3) are the same as in Embodiment 1. In step (4) of the present embodiment, statistics of the transportation and waiting duration t′ of a material truck of PAC asphalt mixture for a physical project is about 10 h, the average value of factory temperature T.sub.1 when driving out of the mixing plant is 180° C., and the average value of arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 170° C.; the thermal aging factor AF=(180+170)×10/2=1750° C..Math.h is calculated for the actual construction.

[0086] The actual construction thermal aging factor AF.sub.0<AF. The SMA asphalt mixture was taken from the pavement site and tested in the forming Marshall specimens indoors with a raveling loss of 36.5%, which is greater than the standard raveling loss of SMA asphalt mixture ≯15%, indicating that the road performance of the asphalt mixture has significantly deteriorated and cannot be used directly. By adjusting the designing scheme, the asphalt mixture is paved in the middle surface layer of the emergency lane, and a 0.5 cm of rock wool layer and 1 cm of rubberized asphalt gravel sealing layer are paved between the middle surface layer and the upper layer in order from the bottom to the top as a thermal insulation layer and waterproof layer. The additional insulation layer and waterproof layer can improve the performance of the surface layer of light spot basalt aggregate, and the additional layers are suitable for use in the case of AF.sub.0<AF<AF.sub.max, where AF.sub.max, preferably, is 2160° C. h.

Embodiment 5

[0087] The basalt aggregate and asphalt mixture used in this embodiment are exactly the same as in Embodiment 3, and steps (1)-(3) are the same as in Embodiment 1. In step (4) of the present embodiment, statistics of the transportation and waiting duration t′ of a material truck of PAC asphalt mixture for a physical project is about 24 h, the average value of factory temperature T.sub.1 when driving out of the mixing plant is 180° C., and the average value of arrival temperature T.sub.2 when the material truck reaches the site and starts paving is 150° C.; the thermal aging factor AF=(180+150)×24/2=3960° C..Math.h is calculated for the actual construction.

[0088] The actual construction thermal aging factor AF>AF.sub.max, AF.sub.max=2160° C..Math.h. SMA asphalt mixture is taken from the pavement site and tested by forming Marshall specimens indoors with a raveling loss close to 100%, and no complete residual specimens is found, the raveling loss is much greater than the SMA asphalt mixture standard ≯15%, indicating that the road performance of the asphalt mixture has been significantly deteriorated and therefore the SMA asphalt mixture cannot be used directly. The production temperature of SMA asphalt mixture needs to be lowered by adding warm mixer; if no measures are taken, the SMA asphalt mixture may only be discarded.

[0089] The pavement performance after construction of basalt aggregates in Embodiments 1-5 above is shown in the following table:

TABLE-US-00005 Pavement damage state Within a 2 years short period after of opening opening to to traffic traffic Thermal aging During (completion (completion Measures factor construction acceptance) acceptance) Embodiment Warm AF < AF.sub.0 No obvious No obvious No obvious 1 mixing + shortened damage damage damage waiting duraiton Embodiment No measures AF < AF.sub.0 No obvious No obvious No obvious 2 have been taken damage damage damage Embodiment No measures AF < AF.sub.0 No obvious No obvious No obvious 3 have been taken damage damage damage Embodiment Adding AF.sub.0 < AF < AF.sub.max No obvious No obvious No obvious 4 waterproof and damage damage damage insulation layers Embodiment No measures AF > AF.sub.max The asphalt mixture is 5 have been taken discarded and unused.

COMPARATIVE EMBODIMENTS

[0090] The comparative embodiments are provided for further illustrating the technical effectiveness of the method of diagnosis and evaluation described in the present application.

Comparative Embodiment 1

[0091] Basalt aggregates are tested for mass loss, abrasion value loss, and impact value loss after 36 h of continuous boiling according to the EU standard BS EN 1367-3:2001 Tests for thermal and weathering properties of aggregates: Part 3: Boiling test for Sonnenbrand basalt, with test results as shown in Table 5. According to the existing evaluation method, the basalt aggregate is a sonnenbrand basalt.

TABLE-US-00006 TABLE 5 Performance of basalt aggregate after continuous boiling for 36 h Time- Test Technical consumed for Diagnostic Test index Unit result requirement diagnosis conclusion Mass loss % 1.5 ≤1 Not less than sonnenbrand Abrasion % 10.6 ≤8 3 days basalt value loss Impact % 8.3 ≤5 value loss

Comparative Embodiment 2

[0092] When diagnosing the same basalt aggregate as in embodiment 1, this comparative embodiment mixes PAC asphalt mixture according to the PAC-13 production ratio (see Table 1) actually used in the project, with an oil-to-rock ratio of 4.9% and 0.1% polyester fiber incorporated. The asphalt mixture is evenly dispersed in a tray, after the asphalt mixture is cooled to room temperature, water of room temperature is added into the tray until the mixture is submerged; the asphalt mixture is stood for 24 h, then the aggregate that bonded together into lumps are taken out from the tray, and broken lightly by hand to observe whether there is asphalt coating peeling phenomenon in the aggregate appearance.

Comparative Embodiment 3

[0093] This comparative embodiment uses the same production ratio of PAC-13 (see Table 1) to mix PAC asphalt mixture with an oil-to-rock ratio of 4.9% and 0.1% polyester fibers when diagnosing the same basalt aggregate as in Embodiment 1. The mixture is evenly dispersed in a tray placed in a 180° C. oven for thermal aging of 5 h; the tray is then removed from the oven, the mixture is allowed to stand for 24 h, and the aggregate lumps bonded together are removed from the tray and lightly broken by hand to observe the appearance of the aggregate to see if the asphalt coating is peeled off. The appearance of the aggregates in Comparative embodiment 2 and Comparative embodiment 3 is observed, and it is found that there is no asphalt coating peeling in Comparative embodiment 2 that has not undergone high-temperature thermal aging and water immersion. The appearance of the aggregates in Comparative embodiment 3, which underwent high-temperature thermal aging, shows a slight peeling of asphalt coating, which is Grade 4. While the aggregate in the embodiment 1 shows severe asphalt coating peeling in appearance as grade 2 after the aggregate undergoes high temperature thermal aging and water immersion. By using the diagnosis method of basalt aggregate sonnenbrand phenomenon proposed in this application, the asphalt coating peeling after thermal aging and water immersion is quickly and accurately diagnosed.

[0094] In addition, the sonnenbrand of basalt aggregate is not diagnosed in Comparative embodiment 2, and the sonnenbrand phenomenon of basalt aggregate is diagnosed in Comparative embodiment 3, but the rating is 4, with a small asphalt coating peeling area, which is subject to human judgment as well as repetition error and reproducibility error, and is prone to the problem that the rating is 5 and the sonnenbrand phenomenon cannot be diagnosed. Embodiment 1 is graded as 2, showing significant asphalt coating peeling, accurately diagnosing the light spot phenomenon in basalt aggregates, and taking a total duration of about 36 h. Compared to Comparative embodiment 1, the diagnostic conclusion is the same, but the time consumption is substantially reduced and the operation is increasingly easy.

Comparative Embodiment 4

[0095] The PAC asphalt mixture blended in Embodiment 1 is evaluated using existing evaluation methods: without any thermal aging treatment, the raveling loss of the mixture is tested according to standard test methods, and the result is 8.2%, which is smaller than the technical requirement of 15%, so it is directly paved in the physical project without using measures such as temperature reduction and shortening the transportation duration. When the asphalt mixture is paved and compacted, the peeling of the asphalt coating appears at the location where the rubber wheel stays in the process of rolling by the rubber wheel roller. In the next day of traffic marking, the location where the marking vehicle turnaround appears a significant amount of asphalt coating peeling phenomenon. After three days of opening for traffic operation, the construction section shows a serious problem of aggregate dislodgement at certain locations, so the construction section is subjected to rework. According to the Highway Performance Assessment Standards (JTG 5210-2018), the pavement breakage rate exceeds 2% and the rating is only medium.

[0096] In the case of Embodiment 1 of this application, the construction quality of PAC asphalt mixture is effectively ensured after adopting measures such as temperature lowering and shortening the transportation duration, and no asphalt coating peeling occurs during the whole construction process and the 2-year operation phase. According to the Highway Performance Assessment Standards (JTG 5210-2018), the pavement breakage rate is less than 2% and the rating is excellent.

Comparative Embodiment 5

[0097] The SMA asphalt mixture of Embodiment 4 is paved in the physical project in the middle layer, with no additional waterproof layer and insulation layer; in the short period of opening to traffic, no obvious phenomenon of asphalt coating peeling or aggregate dislodging occurs. However, in 2 years of operation for completion acceptance, a serious aggregate shedding phenomenon occurs in certain locations of this construction section. According to the Highway Performance Assessment Standards (JTG 5210-2018), the pavement breakage rate exceeds 2% and the rating is only medium.

[0098] In the case of Embodiment 4 of this application, the construction quality of SMA asphalt mixture is effectively ensured after adopting measures of additional waterproof layer and insulation layer, and no asphalt coating peeling phenomenon occurs throughout the construction process and 2 years of opening to traffic operation.

Comparative Embodiment 6

[0099] The SMA asphalt mixture in Embodiment 5 suffers a significant deterioration in performance due to severe thermal aging effects. The SMA asphalt mixture of Embodiment 5 is paved in the physical project, and within a short period of opening to traffic and operation, serious aggregate dislodgement occurs in certain locations of this construction section. According to the Highway Performance Assessment Standards (JTG 5210-2018), the pavement breakage rate exceeds 2% and the rating is only medium.

TABLE-US-00007 TABLE 6 Pavement damage status after construction in Comparative embodiments 4-6 Pavement damage state Within a short period of 2 years after opening to opening to traffic traffic Thermal aging construction (completion (completion Cases Measures factor period acceptance) acceptance) Comparative No AF.sub.0 < AF < AF.sub.max Peeling of Aggregate / embodiment measures asphalt falls off at 4 have been coating certain taken positions and is reworked Comparative No AF.sub.0 < AF < AF.sub.max No obvious No obvious Aggregate embodiment measures damage damage falls off at 5 have been certain taken positions and is reworked Comparative No AF > AF.sub.max No obvious Aggregate / embodiment measures damage falls off at 6 have been certain taken positions and is reworked

[0100] The above embodiments are only several embodiments of the present application with a rather specific and detailed description, but they should not be construed as a limitation of the patent scope of the present application. It should be noted that for a person of ordinary skill in the art, several deformations and improvements may be made without departing from the conception of the present application, all of which belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the claims.