Hot mix asphalt pavement construction procedure 1
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General regulations 1) The mixing plant shall be calibrated before construction, and it shall be calibrated once a month during construction
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2) Before the commencement of construction, the test results of various raw materials and the design of target mix proportion and production mix proportion shall be formally reported to the supervision engineer 10 days in advance
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3) The asphalt pavement shall not be constructed when the temperature is lower than 10 ℃
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The “zero pollution” construction is strictly carried out in the paving process of asphalt mixture
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Reasonably arrange the cross operation among housing construction, mechanical and electrical, traffic safety facilities, greening and protection projects
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4) First install the curb and guardrail, then pave
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The construction of asphalt structure layer shall be continuous
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5) Recycled mineral powder shall not be used in the mixing process
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6) The asphalt and cement concrete mixing plant should be equipped with dust recovery device to effectively control the smoke pollution and strictly control the noise pollution of mechanical construction
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Effective measures shall be taken for construction material transportation vehicles to prevent leakage of materials along the way and pollution of road environment
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2
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Mechanical requirements 1) The equipment of machinery should be able to meet the requirements of the overall project schedule, and the output of equipment should match each other
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2) The minimum requirements of mechanical equipment are shown in table 3-1
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Table 3-1 asphalt pavement construction machinery configuration table machine name, specification, model, rated power (kw) or capacity (M3) or tonnage (T) number required by the place of origin (set) asphalt concrete mixing station 4000 320t / h imported 2 asphalt mixture paver abg882013m3 double drive double vibration roller dd909t1 double drive double vibration roller dd11011t2 double drive double vibration roller dd13013t2 tire roller cp3030t220 ～ 30t dump truck 15t40 double drive Double vibratory roller 4T imported 16000l sprinkler 8t2 asphalt distributor 8t2 floating reference beam 16m2 vibratory roller 30t2 loader 2 ～ 35 crushing screening and sand making equipment 1000m3 / D 43) All transport vehicles involved in the construction shall be equipped with real-time monitoring system for driving condition, load and compartment temperature
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The real-time driving speed control system is installed on the paving and rolling machines
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The cement mixing plant and asphalt mixing building shall be installed with dynamic data real-time transmission monitoring system (black box)
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3
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Material requirements 1) coarse aggregate coarse aggregate shall be crushed stone with sufficient strength and wear resistance, and its surface shall be clean, free of weathering and impurities
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The technical indexes meet the specification requirements
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2) The fine aggregate of fine aggregate asphalt pavement includes machine-made sand and stone chips
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Machine made sand is manufactured by special sand making machine and produced by high quality limestone
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3) The filler mineral powder is processed by limestone, and the soil impurities in the raw stone should be removed
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4) Common asphalt (1) Asphalt must be stored separately according to variety and strength
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The barreled asphalt shall be stacked vertically and covered with tarpaulin（ 2) Good waterproof measures should be taken during the storage, transportation, use and storage of road asphalt
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5) The construction plan of modified asphalt should be reasonably arranged, and the storage time of modified asphalt transported to the site should not exceed 72 hours
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6) Fiber stabilizer SMA Pavement fiber stabilizer shall provide quality certificate when entering the site
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4
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Mix proportion design, mix proportion design using GTM method, and check with Marshall design method, find out the correlation coefficient, so as to control the construction process
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The mix proportion design of asphalt mixture should be carried out in strict accordance with the target mix proportion design, production mix proportion design and production mix proportion verification
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1) Target mix proportion design (1) the maximum theoretical density of mixture in design: for road asphalt, the maximum theoretical density meter should be used to measure, and the theoretical calculation value should be used to check; For modified asphalt, the theoretical calculation method should be used and the measured value should be checked（ 2) Water stability test (1) 48 h immersion Marshall test was used
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Residual stability: ordinary asphalt mixture ≥ 80%, modified asphalt mixture ≥ 85%
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② Freeze thaw splitting test was used
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Residual strength ratio: ordinary asphalt mixture ≥ 75%, modified asphalt mixture ≥ 80%（ 3) High temperature stability test
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The rutting test was used
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Dynamic stability: ordinary asphalt mixture DS ≥ 1200 times / mm, modified asphalt mixture DS ≥ 3000 times / mm（ 4) The target coordination design report shall include the following contents: ① General description: including project overview, material performance summary, synthetic grading list, Marshall test technical index summary, determination of optimal oil consumption, and other descriptions
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② Data and tables of relevant material tests are attached
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③ The data and tables of mixture test process are attached, and the test results of mixture performance are designed
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④ The mix proportion inspection report of the central laboratory (including rotary compaction inspection, etc.) is attached
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2) Design of production mix proportion (1) The relationship between feeding speed and motor speed of cold bin in asphalt mixing plant should be calibrated
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According to the formed relationship curve, the corresponding motor speed should be selected for feeding（ 2) According to the proportion of each cold bin determined by the target mix proportion design, the trial mix method is adopted to make the composite gradation consistent with the design gradation to the maximum extent
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The deviation of the passing rate of the key sieve holes of 4.75mm, 2.36mm and 0.075mm shall not be greater than 1%（ 3) Asphalt content and asphalt content of target mix design ± 0.3% for the mixture, the suitable mixing temperature and time were determined, and Marshall test was carried out（ 4) According to the results of trial mixing, the gradation of production mix proportion and the optimum asphalt content are determined
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The difference between the optimum asphalt dosage and the design result of target mix proportion shall not be greater than ± 0.2％。 3) The verification of production mix proportion shall be conducted according to the results of production mix proportion, and samples shall be taken for Marshall test
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In the aggregate gradation of production mix proportion, it should at least include 0.075mm, 2.36mm, 4.75mm and the passing rate of the sieve with the nominal maximum particle size close to the median value of the design gradation range
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4) The production mix design report should include the following contents: (1) general description: brief introduction and conclusion of the process of production mix design, including the determined screen size of hot bin, the proportion of each hot bin, the mixing time of mixture and the key data of Marshall test, etc（ 2) Accessories: screening test, synthetic grading, Marshall compaction test, extraction test and water stability test of each hot bin
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5
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Test section (first piece project) 1) Before paving the test section, the construction unit shall carry out technical disclosure
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2) The length of the test section shall not be less than 300m
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3) The paving of test section should achieve the following purposes: (1) determine the standard mix proportion of large-area construction（ 2) Determine the paving thickness and loose paving coefficient（ 3) Determine the reasonable construction machinery configuration, including the number and combination of machinery（ 4) To determine the standard construction method: ① control of mixture ratio; ② Mixing temperature and time of mixing plant; ③ The paver’s paving temperature, paving speed, paving width, automatic square type, etc; ④ Compaction sequence, rolling temperature and rolling combination mode of roller; ⑤ Joint method; 4) The summary report of the test section shall include the following contents: (1) general description: the whole process of the test section shall be briefly introduced, and the main data of sampling inspection of the test section shall be provided（ 2) Attached test tables: Marshall test, extraction test, core sample test and other relevant data of test section（ 3) Attachment: test report of target mix proportion and production mix proportion; Sampling inspection report of test section in central laboratory
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5) The summary report of the test section shall be submitted to the supervision engineer for approval before it can be used as the guiding scheme for large-scale construction
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Formal construction can be started only after getting the order of commencement from the director general’s office.
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