Quality control method of asphalt mixture and sampler

Abstract

The invention discloses an asphalt mixture quality control method and a sampler, and the method comprises the following steps: S1, raw material determination and on-site sampling inspection, S2, on-site key parameter acquisition and target mix proportion test, S3, raw material processing temperature parameter determination and production mix proportion test, and S4, mixture blending and quality inspection, the raw material components of the asphalt mixture are asphalt, aggregate and mineral powder, the asphalt is selected from matrix asphalt or modified asphalt, the aggregate is divided into coarse aggregate and fine aggregate according to the particle size, and the mineral powder is limestone mineral powder. According to the quality control method for the asphalt mixture and the sampler, the cleaning ring can wipe the residual mixture to ensure the next sampling accuracy, and the inner cavity of the shell can store the material; a servo motor of the sampling mechanism drives an auger to achieve automatic sampling, manual errors are reduced, a threaded sleeve and a threaded barrel are matched to be convenient to disassemble and assemble, mixing is conducted according to the production mixing ratio, grading is controlled, it is guaranteed that the component proportion is accurate, and the pavement compactness is prevented from being affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of asphalt mixture production, in particular to a quality control method and sampler for asphalt mixture. BACKGROUND

[0002] In the field of road engineering, the quality control of asphalt mixture is a key link to guarantee the performance and durability of pavement, involving raw material inspection, mix design, production mixing and finished product sampling and other technical links. In the related art, the design and application of the quality control method and sampler for asphalt mixture directly affect the stability and reliability of construction quality.

[0003] In the prior art, the quality control of asphalt mixture has many deficiencies: the sampling method lacks randomness during raw material inspection, which can easily lead to insufficient representativeness of the sample, and cannot effectively eliminate unqualified raw materials in advance, increasing the risk of quality defects in subsequent construction; the actual conditions of the construction site (such as temperature, construction area, pavement bearing capacity, etc.) are not fully considered during mix design, the target mix is not consistent with the actual construction requirements, and it is difficult to provide effective basis for production mix; the raw material processing temperature parameters are not clear, and the production mix test is not sufficient, which can easily cause production deviation under different construction environments and affect the quality of the mixture. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a quality control method and sampler for asphalt mixture to solve the technical problems that the target mix is not consistent with the actual construction requirements, it is difficult to provide effective basis for production mix, the raw material processing temperature parameters are not clear, and the production mix test is not sufficient, which can easily cause production deviation under different construction environments and affect the quality of the mixture.

[0005] To achieve the above purpose, the present application provides the following technical solution: a quality control method for asphalt mixture, comprising: S1, raw material determination and on-site sampling inspection: Determine each raw material component of the asphalt mixture, randomly sample each raw material component at the construction site to obtain a sample, and perform performance index inspection on the extracted sample to ensure that the raw material basic quality meets the requirements; random sampling can avoid the situation that the sample is not representative due to local differences in raw materials, and performance index inspection can screen out unqualified raw materials in advance, thereby eliminating subsequent mixture quality defects caused by raw material problems from the source and laying a reliable foundation for the entire quality control process; S2, on-site key parameter acquisition and target mix test: The three key parameters of the construction site, i.e., construction site temperature, construction area and road bearing capacity, are detected and determined, the above three site parameters are integrated into the proportioning design of each raw material component, target mix proportion test is carried out, and three core results, i.e., target mix proportion, grading range and oil-stone ratio range, are determined through the test; the construction site temperature directly affects the workability and setting speed of the mixture, the construction area is related to the raw material dosage planning, and the road bearing capacity determines the strength requirement of the mixture, and the integration of the three into the proportioning design can make the target mix proportion more suitable for the actual construction requirements, and the Superpave design software can accurately determine the core results by combining multiple tests, thereby providing a scientific basis for subsequent production mix proportion; S3, raw material processing temperature parameter determination and production mix proportion test: Three temperature parameters in the raw material processing process, i.e., mixing temperature, discharge temperature and heating temperature of each raw material component, are determined, and the production mix proportion test of each raw material component is carried out in combination with the above temperature parameters to determine the constraint conditions of the production mix proportion; the mixing temperature, discharge temperature and heating temperature directly affect the fusion degree of the raw material and the performance of the mixture, and the determination of the temperature parameters in different intervals can adapt to different construction environments, and the production mix proportion test in combination with the temperature parameters can determine the reasonable range of the proportioning, thereby avoiding quality problems caused by proportioning deviation in the production process; S4, mixture mixing and quality inspection: According to the production mix proportion determined in S3, raw material processing temperature parameter determination and production mix proportion test, each raw material component is mixed and processed to obtain asphalt mixture, the grading composition of each raw material component needs to be controlled during the mixing process to ensure that it meets the production mix proportion requirements, and the produced asphalt mixture is randomly sampled and tested for performance; the mixing according to the production mix proportion can ensure the accurate proportion of the mixture components, the control of the grading composition can avoid the influence of uneven particle size distribution of the aggregate on the road density, and the random sampling inspection can monitor the quality of the mixture product in real time, so that problems in the mixing process can be found in time and adjusted.

[0006] Preferably, in the S1, raw material determination and site sampling inspection, the raw material components of the asphalt mixture are specifically asphalt, aggregate and mineral powder, the asphalt is selected from base asphalt or modified asphalt, the aggregate is classified into coarse aggregate and fine aggregate according to particle size, the mineral powder is limestone mineral powder, and the aggregate is mixed after equal amounts of samples are taken from the top, middle and bottom of the material pile; the base asphalt is suitable for ordinary road surface scenarios, the modified asphalt can improve the high-temperature resistance and aging resistance due to the addition of modifiers, and is suitable for complex climate environments; the classification of aggregate according to particle size facilitates accurate control of the grading to ensure the stability of the mixture skeleton structure; the limestone mineral powder has good hydrophilicity and filling property, and can enhance the bonding force between asphalt and aggregate; equal amounts of samples are taken from different positions of the material pile and mixed, which can avoid the segregation phenomenon of the material pile due to long storage time, and ensure that the aggregate sample can truly reflect the overall quality.

[0007] Preferably, in the S2, field key parameter collection and target mix ratio test, the construction site temperature is detected by 3-5 thermocouples with an accuracy of ±0.5°C, the detection points are evenly distributed in the construction area, the construction area is measured by a laser range finder with a measurement error of ≤±2 mm, the target mix ratio test is carried out by Superpave design software, the input parameters include construction site temperature, construction area, pavement bearing capacity, and material performance test data in S1, raw material determination and field sampling inspection, the test design is not less than 3 groups of mix ratio schemes, and Marshall test is carried out for each scheme; 3-5 thermocouples are evenly distributed to collect the average temperature of the construction area, and the accuracy of ±0.5°C can ensure the accuracy of the temperature data, providing a reliable basis for subsequent temperature parameter determination; the laser range finder with an error of ≤±2 mm can accurately measure the construction area, avoiding waste or insufficient use of raw materials due to area data deviation; Superpave design software integrates multiple key parameters and can simulate the mixing effect under different construction conditions, not less than 3 groups of mix ratio schemes combined with Marshall test can screen out the optimal target mix ratio, improving the scientificity and reliability of mix ratio design.

[0008] Preferably, in the S3, raw material processing temperature parameter determination and production mix ratio test, the raw material processing temperature parameters are adjusted according to the construction site temperature zoning: When the construction site temperature is 25-35°C, the asphalt mixing temperature is controlled at 160-170°C, the aggregate mixing temperature is controlled at 170-180°C, and the discharge temperature is controlled at 150-160°C, and the aggregate heating temperature is consistent with the aggregate mixing temperature; When the construction site temperature is <25°C, the asphalt mixing temperature is increased to 170-180°C, the aggregate mixing temperature is increased to 180-190°C, and the discharge temperature is increased to 160-170°C, to ensure that the temperature of the mixture is not lower than 145°C when transported to the paving site; the temperature drop speed of the mixture during transportation and paving is different at different construction site temperatures, and the processing temperature is adjusted in zoning to compensate for the temperature drop loss: increasing the processing temperature when the temperature is low can avoid the loss of workability of the mixture after transportation to the site due to too low temperature, and cannot be normally paved; the aggregate heating temperature is consistent with the mixing temperature, which can prevent the mixture from being locally overheated or not fully fused due to temperature difference during mixing, to ensure the overall mixing quality of the mixture.

[0009] Preferably, in the S4, mixing and quality inspection of the mixture, the intermittent asphalt mixing machine with real-time temperature monitoring function of the mixing cylinder is used for mixing, and the mixing sequence is dry mixing of aggregate and mineral powder for 10-15s→wet mixing of asphalt for 20-35s. The total mixing time is adjusted according to the single mixing amount: the total mixing time is 30-40s when the single mixing amount is 1-2t, and the total mixing time is 40-60s when the single mixing amount is 2-3t. The mixed mixture needs to be white and non-segregated. The real-time temperature monitoring function of the mixing cylinder can control the temperature in the mixing process in real time, avoid high temperature leading to asphalt aging, and low temperature leading to insufficient mixing. Dry mixing of aggregate and mineral powder can make them mix uniformly, and wet mixing of asphalt can make the asphalt fully wrap the surface of the aggregate, reducing the white material phenomenon. Adjusting the total mixing time according to the mixing amount can ensure that the mixed mixture of different amounts can reach a uniform mixing state. Non-segregation can ensure the uniformity of the performance of the mixed mixture, and improve the overall strength and durability of the pavement after construction.

[0010] Preferably, in the S4, mixing and quality inspection of the mixture, the grading control during mixing: take a sample from the hot bin every hour to inspect the grading, and adjust the cold bin feeding speed when the key sieve grading deviates from the production mix ratio by more than ±1%. Sampling and inspection every hour can monitor the grading change of the aggregate in the hot bin in real time, and timely find the grading deviation caused by unstable cold bin feeding speed. The key sieve grading directly affects the skeleton structure and density of the mixture, and adjusting the feeding speed when the key sieve grading deviates by more than ±1% can quickly correct the grading deviation, ensure that the grading during mixing always meets the production mix ratio requirements, and avoid affecting the pavement quality due to abnormal grading.

[0011] A sampler for quality control of asphalt mixture adopts the above-mentioned quality control method of asphalt mixture, comprising: a protection mechanism and a sampling mechanism, the sampling mechanism is assembled at the bottom of the inner cavity of the protection mechanism, the protection mechanism comprises a shell, a threaded cylinder is inserted at the bottom of the shell, a vertical arm is connected at the bottom of the inner cavity of the shell, and a cleaning ring is connected at the other end of the vertical arm; the shell can protect the internal sampling mechanism from external collision and dust pollution, prolonging the service life of the equipment; the threaded cylinder cooperates with the threaded sleeve of the subsequent sampling mechanism to fix the shell and the hollow column; the vertical arm fixes the cleaning ring, which can wipe the residual mixture outside the hollow column when the shell is disassembled, avoiding the influence of residual samples on the accuracy of the next sampling, and the material sampled by the sampling mechanism is stored in the inner cavity of the shell; The sampling mechanism comprises a hollow column, the inner cavity of the hollow column is rotationally connected with an auger, the outer part of the hollow column is uniformly provided with a discharge port, the outer part of the hollow column is sleeved with a threaded sleeve, the threaded sleeve is threadedly connected with a threaded cylinder, the top of the hollow column is provided with a servo motor, and the output end of the servo motor is connected with the auger; the servo motor drives the rotation of the auger, the mixed material below can be conveyed to the discharge port through the hollow column, automatic sampling is realized, and the error of manual sampling is reduced; the threaded sleeve is threadedly connected with the threaded cylinder, the shell and the hollow column can be fixed, and meanwhile, the threaded sleeve facilitates the disassembly; the uniform discharge port can ensure that the test sample is uniformly discharged, and the representative sample is conveniently collected.

[0012] Preferably, the upper end of the shell is provided with a handle, the outer part of the handle is sleeved with an anti-skid sleeve, and the inner cavity of the shell is provided with a motor shell; the handle facilitates the operator to hold the sampler, the anti-skid sleeve can increase the friction between the hand and the handle, the device is prevented from slipping and falling during sampling, and the operation safety is improved; the motor shell can provide secondary protection for the servo motor, prevents dust and debris in the shell from entering the motor, and ensures the stable operation of the servo motor.

[0013] Preferably, the front of the shell is provided with an electronic module, the electronic module comprises a display module, a communication module, a control module and a power module, the top of the threaded cylinder is designed as a slope, the inner cavity of the threaded cylinder is provided with a sealing gasket, and the inner cavity of the sealing gasket is slidingly connected with the outer part of the shell; the display module can display the sampling depth, sampling time and other data in real time, and facilitates the operator to record; the communication module can transmit the sampling data to an external terminal, realizes the remote storage and analysis of data; the control module can control the rotating speed of the servo motor, and then control the sampling speed; the power module provides power support for the electronic module and the servo motor, and ensures the normal operation of the device; the slope design of the top of the threaded cylinder facilitates the smooth lifting of the hollow column, and reduces the jamming; the sealing gasket can enhance the sealing property between the threaded cylinder and the shell, prevents foreign matters from entering the inside of the protection mechanism, and protects the internal components.

[0014] Preferably, the outer part of the servo motor is uniformly provided with a limiting frame, and the limiting frame is connected with the top of the hollow column; the limiting frame can stably fix the servo motor on the top of the hollow column, prevents the servo motor from being deviated due to vibration during operation, ensures the coaxiality between the output end of the motor and the auger, ensures the stable rotation of the auger, and improves the stability and sampling efficiency of the sampling process.

[0015] To sum up, the present application provides a quality control method for asphalt mixture and a sampler, and has the following beneficial effects: The quality control method and sampler of the asphalt mixture can avoid insufficient sample representativeness, eliminate unqualified raw materials in advance, and avoid subsequent quality defects from the source; the construction site temperature, construction area and pavement bearing capacity are integrated into the proportioning design, the core parameters are determined through tests, the target mixing ratio is more in line with the actual situation, and the basis for the production mixing ratio is provided; the raw material processing temperature parameters are determined and combined with the production mixing ratio test, which can adapt to different construction environments and determine the reasonable range of proportioning, so as to avoid production deviation and quality problems; the production mixing ratio is mixed and the gradation is controlled, the component proportion is accurate, the pavement compactness is avoided, the random sampling inspection can also monitor the quality of the finished product in real time, and the mixing problem is adjusted in time. In the matched sampler, the shell of the protection mechanism can protect the internal components and prolong the service life, the threaded barrel can be fixed with the sampling mechanism, the cleaning ring can wipe the residual mixture to ensure the accuracy of the next sampling, and the shell cavity can store the material; the servo motor of the sampling mechanism drives the auger to realize automatic sampling, reduces the manual error, and the threaded sleeve and the threaded barrel are matched to facilitate disassembly and assembly. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a workflow diagram of the present application Figure 2 is an external schematic view of the protection mechanism of the present application Figure 3 is a partial cross-sectional view of the protection mechanism of the present application Figure 4 is a partial cross-sectional view of the sampling mechanism of the present application Figure 5 is an external schematic view of the motor shell of the present application

[0017] BRIEF DESCRIPTION OF DRAWINGS: 1, protection mechanism; 11, shell; 12, threaded barrel; 13, motor shell; 14, vertical arm; 15, cleaning ring; 2, sampling mechanism; 21, hollow column; 22, auger; 23, threaded barrel; 24, servo motor; 25, limiting frame; 26, discharge port; 3, electronic module; 4, motor shell DETAILED DESCRIPTION

[0018] The present application provides a technical solution, please refer to Figure 1 A quality control method of asphalt mixture, comprising: S1, raw material determination and on-site sampling inspection Determine the components of the asphalt mixture, and the components of the construction site are randomly sampled to obtain samples, and the performance index test is carried out on the extracted samples to ensure that the raw material basic quality meets the requirements; Through random sampling, the sample can be avoided due to the local difference of raw materials, and the performance index test can screen out unqualified raw materials in advance, so as to prevent the subsequent mixture quality defects caused by raw material problems, and lay a reliable foundation for the whole quality control process; S2, on-site key parameter acquisition and target mix ratio test: Detect and determine the three key parameters of the construction site: construction site temperature, construction area and road bearing capacity, integrate the above three key parameters into the proportioning design of each raw material component, carry out target mix ratio test, and determine three core results: target mix ratio, gradation range and oil stone ratio range; The construction site temperature directly affects the workability and setting speed of the mixture, the construction area is related to the raw material consumption planning, and the road bearing capacity determines the strength requirement of the mixture. Integrating the three into the proportioning design can make the target mix ratio more suitable for the actual construction demand, and the Superpave design software can accurately determine the core results by combining multiple tests, providing a scientific basis for the subsequent production mix ratio; S3, raw material processing temperature parameter determination and production mix ratio test: Determine the three temperature parameters in the raw material processing process: mixing temperature, discharge temperature and heating temperature of each raw material component, and carry out production mix ratio test on the proportioning of each raw material component combined with the above temperature parameters to determine the constraint conditions of production mix ratio; Mixing temperature, discharge temperature and heating temperature directly affect the fusion degree of raw materials and the performance of the mixture, and the temperature parameters are determined in different intervals to adapt to different construction environments. Combined with the temperature parameters, the production mix ratio test can determine the reasonable range of the mix ratio, and avoid quality problems caused by mix ratio deviation in the production process; S4, mixture mixing and quality inspection: According to the production mix ratio determined in S3, raw material processing temperature parameter determination and production mix ratio test, the raw material components are mixed and processed to obtain asphalt mixture. The gradation composition of each raw material component needs to be controlled during mixing to ensure that it meets the production mix ratio requirements. Randomly sample the produced asphalt mixture, and test the performance of the sample; Mixing according to the production mix ratio can ensure the accuracy of the mixture component ratio, controlling the gradation composition can avoid the influence of uneven particle size distribution of aggregate on road density, and random sampling inspection can monitor the quality of the mixture product in real time, and find out the problems in the mixing process and adjust in time.

[0019] In S1, raw material determination and on-site sampling inspection, the raw material components of the asphalt mixture are specifically asphalt, aggregate and mineral powder, wherein the asphalt is selected from base asphalt or modified asphalt, the aggregate is classified into coarse aggregate and fine aggregate according to particle size, the mineral powder is limestone mineral powder, and the aggregate is mixed after equal amounts of samples are taken from the top, middle and bottom of the material pile; the base asphalt is suitable for ordinary pavement scenarios, the modified asphalt can improve high-temperature resistance, aging resistance and other properties due to the addition of modifiers, and is suitable for complex climate environments; the classification of aggregate according to particle size facilitates accurate control of gradation and ensures the stability of the mixture skeleton structure; the limestone mineral powder has good hydrophilicity and filling property, which can enhance the bonding force between asphalt and aggregate; taking equal amounts of samples from different positions of the material pile and mixing them can avoid the segregation phenomenon caused by long storage time of the material pile, and ensure that the aggregate sample can truly reflect the overall quality.

[0020] In S2, on-site key parameter collection and target mix ratio test, the construction site temperature is detected by 3-5 thermocouple thermometers with an accuracy of ±0.5°C, the detection points are uniformly distributed in the construction area, the construction area is measured by a laser range finder with a measurement error of ≤±2mm, the target mix ratio test is carried out by using Superpave design software, the input parameters include construction site temperature, construction area, pavement bearing capacity and raw material performance test data in S1, raw material determination and on-site sampling inspection, and the test design has not less than 3 groups of mixing schemes, and each group of schemes carries out Marshall test; the uniform distribution of 3-5 thermocouples can comprehensively collect the average temperature of the construction area, and the accuracy of ±0.5°C can ensure the accuracy of the temperature data, providing a reliable basis for subsequent temperature parameter determination; the laser range finder with an error of ≤±2mm can accurately measure the construction area, avoiding waste or insufficient use of raw materials due to area data deviation; the Superpave design software integrates multiple key parameters and can simulate the mixing effect under different construction conditions, not less than 3 groups of mixing schemes combined with Marshall test can screen out the optimal target mix ratio, improving the scientificity and reliability of the mixing design.

[0021] In S3, raw material processing temperature parameter determination and production mix ratio test, the raw material processing temperature parameters are adjusted according to the construction site temperature interval: When the construction site temperature is 25-35°C, the asphalt mixing temperature is controlled at 160-170°C, the aggregate mixing temperature is controlled at 170-180°C, and the discharge temperature is controlled at 150-160°C, and the aggregate heating temperature is consistent with the aggregate mixing temperature; When the construction site temperature is <25℃, the asphalt mixing temperature is increased to 170-180℃, the aggregate mixing temperature is increased to 180-190℃, and the discharge temperature is increased to 160-170℃, to ensure that the temperature of the mixture is not lower than 145℃ when it is transported to the paving site; the temperature drop speed of the mixture during transportation and paving varies with the construction site temperature, and the processing temperature is adjusted in different zones to compensate for the temperature drop loss: when the temperature is low, the processing temperature is increased to avoid the loss of workability of the mixture due to too low temperature after it is transported to the site, which cannot be normally paved; the heating temperature of the aggregate is consistent with the mixing temperature, which can prevent the local overheating or insufficient fusion of the aggregate during mixing, to ensure the overall mixing quality of the mixture.

[0022] In the mixing and quality inspection of the mixture, the intermittent asphalt mixing machine with real-time temperature monitoring function of the mixing cylinder is used for mixing, and the mixing sequence is dry mixing of aggregate and mineral powder for 10-15s→wet mixing of asphalt for 20-35s, and the total mixing time is adjusted according to the single mixing amount: the total mixing time is 30-40s when the single mixing amount is 1-2t, and the total mixing time is 40-60s when the single mixing amount is 2-3t, and the mixed mixture needs to be white and non-segregation; the real-time temperature monitoring function of the mixing cylinder can control the temperature in the mixing process in real time, to avoid the aging of asphalt due to too high temperature and the insufficient mixing due to too low temperature; dry mixing of aggregate and mineral powder can make them uniformly mixed, and wet mixing of asphalt can make the asphalt fully cover the surface of the aggregate, to reduce the white material phenomenon; adjusting the total mixing time according to the mixing amount can ensure that the mixture with different amounts can be uniformly mixed; non-segregation can ensure the uniform performance of the mixture and improve the overall strength and durability of the pavement after construction.

[0023] In the mixing and quality inspection of the mixture, the grading control during mixing: take a sample from the hot bin every hour to test the grading, and adjust the feeding speed of the cold bin when the key sieve grading deviates from the production mix ratio by more than ±1%; sampling and testing every hour can monitor the grading change of the aggregate in the hot bin in real time, and timely find the grading deviation caused by unstable feeding speed of the cold bin; the key sieve grading directly affects the skeleton structure and density of the mixture, and adjusting the feeding speed when the key sieve grading deviates by more than ±1% can quickly correct the grading deviation, to ensure that the grading during mixing always meets the production mix ratio requirements, and avoid the influence of abnormal grading on the pavement quality.

[0024] Please refer to Figure 2 、 Figure 3 、 Figure 4 and Figure 5The application discloses a sampler for quality control of asphalt mixture, adopts the quality control method of the asphalt mixture, and comprises a protection mechanism 1 and a sampling mechanism 2, wherein the sampling mechanism 2 is arranged at the bottom of the inner cavity of the protection mechanism 1, the protection mechanism 1 comprises a shell 11, a threaded cylinder 12 is arranged at the bottom of the shell 11, a vertical arm 14 is connected to the bottom of the inner cavity of the shell 11, and a cleaning ring 15 is connected to the other end of the vertical arm 14; the shell 11 can protect the internal sampling mechanism 2 from external collision and dust pollution, thereby prolonging the service life of the equipment; the threaded cylinder 12 is matched with a threaded sleeve 23 of the subsequent sampling mechanism 2, so that the shell 11 and a hollow column 21 can be fixed; the vertical arm 14 fixes the cleaning ring 15, when the shell 11 is disassembled, the cleaning ring 15 can wipe the residual mixture outside the hollow column 21, so that the accuracy of the next sampling is not affected by the residual sample, and the material sampled by the sampling mechanism 2 is stored in the inner cavity of the shell 11. The sampling mechanism 2 comprises the hollow column 21, a screw conveyor 22 is rotatably connected to the inner cavity of the hollow column 21, discharge ports 26 are uniformly arranged on the outer portion of the hollow column 21, the threaded sleeve 23 is sleeved on the outer portion of the hollow column 21, the threaded sleeve 23 is threadedly connected with the threaded cylinder 12, a servo motor 24 is arranged at the top of the hollow column 21, and the output end of the servo motor 24 is connected with the screw conveyor 22; the servo motor 24 drives the screw conveyor 22 to rotate, so that the mixture below can be conveyed to the discharge ports 26 through the hollow column 21, the automatic sampling is realized, and the error of manual sampling is reduced; the threaded sleeve 23 is threadedly connected with the threaded cylinder 12, so that the shell 11 and the hollow column 21 can be fixed and simultaneously conveniently disassembled; the discharge ports 26 are uniformly arranged, so that the sample can be uniformly discharged and collected.

[0025] A handle 4 is arranged at the upper end of the shell 11, an anti-skid sleeve is sleeved on the outer portion of the handle 4, and a motor shell 13 is arranged at the top of the inner cavity of the shell 11; the handle 4 is convenient for an operator to hold the sampler, the anti-skid sleeve can increase the friction between the hand and the handle 4, so that the sampler is prevented from slipping and falling during sampling, and the operation safety is improved; the motor shell 13 can secondarily protect the servo motor 24, so that dust and debris in the shell 11 are prevented from entering the motor, and the stable operation of the servo motor 24 is ensured.

[0026] The front surface of the shell 11 is provided with an electronic module 3, which includes a display module, a communication module, a control module and a power module, the top of the threaded cylinder 12 is designed as an inclined surface, the inner cavity of the threaded cylinder 12 is provided with a sealing gasket, and the inner cavity of the sealing gasket is in sliding connection with the outside of the shell 11; the display module can display real-time sampling depth, sampling time and other data, which is convenient for the operator to record; the communication module can transmit the sampling data to the external terminal to realize remote storage and analysis of the data; the control module can control the speed of the servo motor 24, thereby controlling the sampling speed; the power module provides power support for the electronic module 3 and the servo motor 24, ensuring the normal operation of the equipment; the inclined surface design at the top of the threaded cylinder 12 facilitates smooth lifting of the hollow column 21, reducing the jamming; the sealing gasket can enhance the sealing between the threaded cylinder 12 and the shell 11, prevent foreign matter from entering the inside of the protection mechanism 1, and protect the internal components.

[0027] The outer surface of the servo motor 24 is uniformly provided with a limiting frame 25, and the limiting frame 25 is connected with the top of the hollow column 21; the limiting frame 25 can stably fix the servo motor 24 on the top of the hollow column 21, prevent the servo motor 24 from shifting position due to vibration during operation, ensure the coaxiality of the motor output end and the auger 22, ensure the stable rotation of the auger 22, and improve the stability and sampling efficiency of the sampling process.

[0028] The working principle and process of the scheme are as follows: first, S1, raw material determination and on-site sampling inspection, determine that the raw material components are asphalt, aggregate and mineral powder, the asphalt is selected as matrix asphalt or modified asphalt, the aggregate is divided into coarse and fine aggregate according to particle size, and the mineral powder is limestone powder. Randomly sample the on-site raw materials, mix equal amounts of aggregate from the top, middle and bottom of the material pile, test the performance of the sample, screen out unqualified raw materials from the source, and lay the foundation for quality. After S1 is completed, S2, on-site key parameter collection and target mix ratio test, three parameters are measured: construction site temperature with 3-5 ±0.5℃ thermocouple thermometer, construction area with ≤±2mm error laser range finder, and road bearing capacity. The parameters and S1 raw material data are integrated into the ratio, the target mix ratio test is made by Superpave software, at least 3 groups of schemes are set and Marshall test is made, the target mix ratio, gradation and oil stone ratio range are determined, and the basis for production mix ratio is provided. Then, S3, raw material processing temperature parameter determination and production mix ratio test, determine the mixing, discharging and heating temperature, and adjust according to the on-site temperature interval: when the temperature is 25-35℃, the asphalt mixing temperature is 160-170℃, the aggregate mixing temperature is 170-180℃, the discharging temperature is 150-160℃, and the aggregate heating temperature is the same as the mixing temperature; when the temperature is <25℃, each temperature is increased by 10℃, and the mixture temperature is ensured to be ≥145℃ when it arrives at the site. Combined with the temperature parameters, the production mix ratio test is carried out to determine the constraint conditions. Then S4, mixture mixing and quality inspection, with real-time temperature control intermittent mixing machine, according to S3 production mixing, the order is aggregate + mineral powder dry mixing 10-15s → add asphalt wet mixing 20-35s, total time according to 1-2t with 30-40s, 2-3t with 40-60s, no white material, no segregation after mixing. Every hour from the hot bin sampling inspection grading, key sieve deviation ± 1% or more to adjust the cold bin feeding speed, random sampling mixture performance, real-time control quality. The sampling device is equipped with a protection mechanism 1 and a sampling mechanism 2, the sampling mechanism 2 is installed in the bottom of the inner cavity of the protection mechanism 1. The shell 11 of the protection mechanism 1 protects the internal components, the threaded cylinder 12 is fixedly connected with the threaded sleeve 23 of the sampling mechanism 2, the vertical arm 14 is connected with the cleaning ring 15, and the sampled material is stored in the shell. The hollow column 21 of the sampling mechanism 2 is connected with the auger 22, the outer opening is uniformly provided with the discharge port 26, the servo motor 24 drives the rotation of the auger 22, and automatic sampling is realized. The upper end of the shell 11 is provided with a non-slip sleeve, and the inner cavity top is provided with a motor shell 13. The front electronic module 3 of the shell 11 includes display, communication, control and power module; the top of the threaded cylinder 12 is inclined and provided with a sealing pad; and the servo motor 24 is provided with an outer limiting frame 25.

Claims

1. A method for quality control of asphalt mixtures, characterized in that, include: S1. Raw material selection and on-site sampling and testing: The raw material components of the asphalt mixture are determined, and samples are randomly sampled from each raw material component at the construction site. The performance indicators of the sampled samples are tested to ensure that the basic quality of the raw materials meets the requirements. S2. On-site key parameter collection and target mix ratio test: The three key parameters of the construction site were detected and determined: construction site temperature, construction area and pavement bearing capacity. These three site parameters were then incorporated into the proportioning design of each raw material component. Target mix proportion tests were conducted, and three core results were clarified through the tests: target mix proportion, gradation range and asphalt-aggregate ratio range. S3. Determination of raw material processing temperature parameters and production mix ratio test: The three main temperature parameters in the raw material processing process are determined: the mixing temperature of each raw material component, the discharge temperature, and the heating temperature. Based on the above temperature parameters, a production mix design test is conducted on the proportion of each raw material component to clarify the constraints of the production mix design. S4. Mixing and Quality Inspection of the Mixture: Based on the production mix design determined in the S3 raw material processing temperature parameter determination and production mix design test, each raw material component is mixed to obtain asphalt mixture. During the mixing process, the gradation composition of each raw material component needs to be controlled to ensure that it meets the production mix design requirements. Random samples are randomly selected from the produced asphalt mixture, and the performance of the samples is tested.

2. The quality control method for asphalt mixtures according to claim 1, characterized in that: In S1, the raw material determination and on-site sampling and testing, the raw material components of the asphalt mixture are asphalt, aggregate and mineral powder. The asphalt is selected from base asphalt or modified asphalt. The aggregate is divided into coarse aggregate and fine aggregate according to particle size. The mineral powder is limestone mineral powder. Equal amounts of aggregate samples are taken from the top, middle and bottom of the stockpile and then mixed.

3. The quality control method for asphalt mixtures according to claim 1, characterized in that: In S2, on-site key parameter collection and target mix proportion test, the construction site temperature is detected by 3-5 thermocouple thermometers, with the detection points evenly distributed in the construction area. The construction area is measured by a laser rangefinder. The target mix proportion test is carried out using Superpave design software. The input parameters include the construction site temperature, construction area, pavement bearing capacity, and raw material performance test data from S1, raw material determination and on-site sampling and testing. The test design includes no less than 3 mix proportion schemes, and each scheme undergoes a Marshall test.

4. The quality control method for asphalt mixtures according to claim 1, characterized in that: In S3, the determination of raw material processing temperature parameters and the production mix ratio test, the raw material processing temperature parameters are adjusted according to the temperature range of the construction site: When the temperature at the construction site is 25-35℃, the asphalt mixing temperature is controlled at 160-170℃, the aggregate mixing temperature is controlled at 170-180℃, the discharge temperature is controlled at 150-160℃, and the aggregate heating temperature is the same as the aggregate mixing temperature. When the temperature at the construction site is <25℃, the asphalt mixing temperature is increased to 170-180℃, the aggregate mixing temperature is increased to 180-190℃, and the discharge temperature is increased to 160-170℃, to ensure that the temperature of the mixture is not lower than 145℃ when it is transported to the paving site.

5. The quality control method for asphalt mixtures according to claim 1, characterized in that: In the S4 stage, mixing and quality inspection of the mixture, an intermittent asphalt mixing machine with real-time temperature monitoring of the mixing cylinder is used for mixing. The mixing sequence is: dry mixing of aggregate and mineral powder for 10-15 seconds → wet mixing of asphalt for 20-35 seconds. The total mixing time is adjusted according to the amount of each batch: 30-40 seconds for a batch of 1-2 t, and 40-60 seconds for a batch of 2-3 t. The mixed material must be free of white spots and segregation after mixing.

6. The quality control method for asphalt mixtures according to claim 1, characterized in that: In the S4 mixing and quality inspection of the mixture, the gradation control during the mixing process is as follows: a sample is taken from the hot silo every hour to check the gradation. If the gradation of the key sieve holes deviates from the production mix ratio by more than ±1%, the feeding speed of the cold silo is adjusted.

7. A sampler for quality control of asphalt mixtures, employing the quality control method for asphalt mixtures according to any one of claims 1-6, comprising: The device includes a protection mechanism (1) and a sampling mechanism (2), wherein the sampling mechanism (2) is assembled at the bottom of the inner cavity of the protection mechanism (1), and is characterized in that: the protection mechanism (1) includes a housing (11), a threaded cylinder (12) is inserted into the bottom of the housing (11), a vertical arm (14) is connected to the bottom of the inner cavity of the housing (11), and a cleaning ring (15) is connected to the other end of the vertical arm (14). The sampling mechanism (2) includes a hollow column (21), with an auger (22) rotatably connected to the inner cavity of the hollow column (21). The hollow column (21) has a uniformly distributed discharge port (26) on its outer side. A threaded sleeve (23) is fitted onto the outer side of the hollow column (21), and the threaded sleeve (23) is threadedly connected to the threaded cylinder (12). A servo motor (24) is provided at the top of the hollow column (21), and the output end of the servo motor (24) is connected to the auger (22).

8. A sampler for quality control of asphalt mixtures according to claim 7, characterized in that: The upper end of the housing (11) is provided with a handle (4), and the outside of the handle (4) is fitted with an anti-slip sleeve. The top of the inner cavity of the housing (11) is provided with a motor housing (13).

9. A sampler for quality control of asphalt mixtures according to claim 7, characterized in that: An electronic module (3) is provided on the front of the housing (11). The electronic module (3) includes a display module, a communication module, a control module and a power module. The top of the threaded cylinder (12) is designed with a slope. A sealing gasket is provided in the inner cavity of the threaded cylinder (12). The inner cavity of the sealing gasket is slidably connected to the outside of the housing (11).

10. A sampler for quality control of asphalt mixtures according to claim 7, characterized in that: The servo motor (24) is uniformly provided with limit frames (25) on its exterior, and the limit frames (25) are connected to the top of the hollow column (21).

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