Construction machinery accessories house 2021-05-0711:19:281
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The main quality requirements of coarse and fine aggregates used for asphalt surface course should be kept in mind
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The apparent density should be greater than 2.5, crushing should be less than 128, abrasion should not exceed 130, flat height should be more than 115, polishing should be more than 42, fine aggregate sand equivalent, lower limit should be 60%
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2
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The transparent layer and adhesive layer of asphalt pavement should be permeated with thin oil, and the base course should be sprinkled when it is slightly dry, so that it will not flow and has no surface film, and the quality of reaching the index is good; Stick to the upper and lower layers of the oil union, do not infiltrate, should form a film, between the upper and lower layers to prevent sliding, grasp the amount of the most important
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3
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Asphalt mixture proportion design has three stages: target production and verification, proper oil use, good gradation and good mixing
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4
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In Marshall test of hot plate asphalt mixture, the size of the specimen should be strictly controlled and the hammer height should be accurate; The quantity of materials to be used must be verified, and the compaction temperature must meet the requirements
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5
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The standard curing of Marshall specimens should be strictly controlled in temperature and time; The test is fast and the operation is accurate, and the key is to guide the construction
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6
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The mixing equipment and mixing equipment of hot mix asphalt mixture should be advanced, complete and coordinated; The mixing time should be controlled well, the temperature should be suitable and the material should be mixed evenly
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7
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The appearance quality of mixing asphalt mixture should be strictly controlled, the heating temperature should be strictly controlled, and the material preparation and measurement should be accurate; The mixture is even without white, and the color is bright without segregation
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8
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Paving the surface course of hot mix asphalt mixture is the requirement of the lower bearing course
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The width of the road meets the requirements
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The lower layer is flat without looseness
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It can be paved only after the treatment is qualified
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This is the key to the quality
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9
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Paving speed: the paving speed should be slow, the continuous paving should be carried out at a uniform speed, the paving speed should be fixed, the mixing quantity should be fixed, and the paving surface should be flat
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10
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The initial rolling of hot mix asphalt mixture should follow the paver closely, the control principle should not crack and move, the front end should be statically stepped, and the inclined pressing should be used to eliminate the step to ensure the smoothness; After the initial pressure is followed by the re pressing, the tire vibrates, the pressing speed and times are controlled, and the straightedge is used to check and flatten; Static pressure is adopted for final pressure, with good quality at high limit of pressure temperature, two times of static pressure to eliminate wheel trace, and the first place of smooth density
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11
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The rolling rules should be started slowly instead of suddenly stopping, and it is not advisable to turn around in the middle; Stop vibration and start vibration again in return to avoid displacement and cracks
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12
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The longitudinal and transverse joints of hot mix asphalt mixture surface course shall be rolled, and the longitudinal and transverse joints shall be staggered
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After the longitudinal hot joint is rolled, the cold joint hot material shall be rolled for 15cm, and the transverse joint shall be rolled horizontally
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After the wheel width is finished, the longitudinal joint shall be rolled again, and the seamless trace shall be measured while pressing
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13
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In the construction of modified asphalt mixture, it is very important to control the modified asphalt mixture and prevent segregation
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Attention should be paid to temperature control and rolling, and the quality of pavement construction is good
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14
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SMA asphalt mastic mixture design steps according to the provisions of material selection, technical parameters up to the target; Asphalt leakage to test, do not meet the requirements of re adjustment; Whether anti spalling is needed or not is known by water stability test
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15
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SMA construction control points should pay attention to the material gradation, the proportion design should be well controlled, the equipment should be improved to improve the efficiency, and the temperature control is very important; Paving and rolling according to the regulations, the pavement quality can be high..
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