Distribution of Modified Emulsified Asphalt Mixture
1. Thoroughly clean and flush the dirt, stones, mortar and other pollutants on the base layer before the stall, and the work shall be completed one day before the stall.
2. Spread the asphalt adhesive layer. Key points of quality control are as follows,
1) the quality of adhesive oil shall meet the specification requirements;
2) to glue layer oil consumption control between 0.3 ~ 0.4 ㎏ / ㎡, and should be spread evenly, less local spread and spread application of artificial fill is aspersed or be shaving;
3) dirt and dust on the road surface should be cleaned. When there is clay, apply a water brush to clean the surface and pour after it is dry.
4) the adhesive bitumen should be emulsified and demulsified before spreading, and after the water evaporates, it should not be contaminated.
3.Paving
1) paving temperature should be controlled between 170 ℃ ~ 180 ℃, shall not be lower than 160 ℃;
2) before each stall, the spreader should be adjusted to the optimal state, and the automatic material level device at both ends of the screw spreader should be adjusted to match the speed of the material door switch and chain plate feeder. Spiral case of shoes at slightly above the center of the spiral case for degrees, make the archives material of iron plate plate before and after the mixture evenly distributed in the whole wide scope, avoid paving segregation phenomenon, and analysis, adjust the thickness of aggregate is uniform at any time, detection height is in accordance with the regulations, in order to adjust the above-mentioned whenever possible. Before paving mixture, shall, in accordance with the provisions of preheat iron plate to temperature (not less than 85 ℃), paving in the iron plate should be used when strong compaction level, make the initial compaction no less than 85%, paver screed must be joining together tightly, do not have aperture, prevent card into the material to pull the road streaks;
3) the above layer paving thickness and the flatness is controlled by the balance beam, shall not adopt any wire guide way of elevation control, should pay close attention to the balance beam size, found that adhesive is expected to keep clear of in time, prevent to produce. Before the paving machine walks, the ironing plate shall be made with the board in strict accordance with the height of the loose paving, so as to ensure the initial thickness of the paving meets the requirements.
4) to continuous and stable paving, paver paving speed should be according to the situation of the output of mixer, construction machinery and paving thickness adjusted according to 2.5 m/min or so choose, do it slowly, uniform continuous paving;
5) the construction personnel shall not enter and trample the paving mixture before it is compacted. General artificial renovation, shall not be used only under special circumstances, should be under the guidance of technical personnel at the scene, allowing with artificial added or replace the mixture, defect serious when be eradicated, and adjust the spreader or modified paving technique;
6) shall, from time to time, in the process of paving loose height of test and ensure that loose laying thickness deviation within 0 ~ 3 ㎜. Visually measure the quality of the mixture (including the mixing quality and mixing ratio), and report the problem to the technical person in time for handling;
7) attention should be paid to the operating procedures of the spreader bucket to reduce coarse aggregate segregation. Hopper spreader sets should be in scraper has yet to show, there are about 10 ㎝ thick hot when one material, this is when the lorry just quit, and should be hopper resumed in situ, the two wings of a lorry can begin discharging, achieve continuous feeding, and avoid the coarse aggregate concentration;
8) it is forbidden to skip the impact paver, skip should stop in from 20 ㎝ paver front place, for the gap, the spreader depend on and promote skip ahead. Observe the quality of the paving at any time, and timely analyze the causes of segregation or other abnormal phenomena and deal with them. The scattered materials scattered by the cart in the spread area must be removed in time.
9) in case of machine failure, rain or other reasons that cannot be spread continuously, inform the mixing group of the situation in time and report to the technical person in charge. When paving in the rain, to immediately stop the construction, and eliminate not compaction, forming the mixture of wet mixture should be abandoned, shall not be discharged into the paving, the next layer before fully dry, after the rain may not continue to paving.
The compaction of the modified emulsified asphalt mixture
1. The compaction and compaction of the modified emulsified asphalt mixture shall be carried out in accordance with the principles of "follow closely, slow pressure, high frequency and low amplitude".
2. The rolling temperature, speed and pass number shall be strictly in accordance with the specifications.
3. Roller compaction must be carried out in a balanced and continuous manner to prevent the change of compaction degree caused by temperature change and affect the compaction degree and flatness. RCC should begin from the road edge to start within 30 to 40 ㎝, in order to prevent the asphalt mixture extrusion, while allowing the lateral edge of asphalt cooling to produce steady shear zone, to facilitate the compaction.
4, using vibratory roller compaction of modified asphalt pavement, the overlap of the wheel track roller width should not exceed 20 ㎝; When using a statically loaded roller, the track of the roller should overlap 1/3 ~ 1/2 of the crushing width.
5. When the modified asphalt mixture is crushed, a special person shall be responsible for directing and coordinating the crushing routes and rolling times of each roller, so that the paving surface can reach the required compaction degree in a relatively short time. The length of roller compaction should not be too short, nor too long, too short to be easy to roll, and too long temperature will cool down, causing the roller compaction is not solid, so the length of roller compaction is generally controlled within 30 ~ 50m.
6. During crushing, vibration should be started before vibration, vibration should be stopped first and then stop. The rotation should be slow and stable. The course and direction should not be changed suddenly. The rollers should be in the trapezoid shape and should not be on the same section.
7. Fill with water before starting rolling; In front of the water tank of water gush out, should be timely add water, add water should be in forming pavement has cooled, avoid by all means stick round occur due to water shortages, caused by sticky wheel marks seriously affect the appearance and quality of the road.
8. The starting point of the roller compaction operation section shall be marked, and it is better to insert flags to represent it, so as to avoid pressure leakage.
9, the road in front of the cooling after rolling, any vehicle machinery shall not be parked on the road (including gas, water roller), and to prevent the ore material, debris, oil fell on the new layer of pavement, etc. Road is cooled to 50 ℃ open to traffic.
Treatment of modified emulsified asphalt pavement joints
Horizontal seams are encountered every day. Its particular way is, flat seam paver in 1 m place before the end screed to lift off slightly, shovel by artificial will end mixture again after roller compaction, and then use 3 m straight edge roughness examination, and then will slope cutting and clear with cutting machine, a portion of the kerf width must be straight, will clean the hem of pollutants and coating layer of asphalt. Before starting the next day paver screed to preheating, the screed all fell in the former spread on the surface of the pad board, the thickness of loose laying thickness and the difference between the compaction thickness, screed to front end and cutting edge alignment, under the spiral case is full of mixture, paver started slowly, paving narimatsu pave asphalt mixture paving layer, the thickness of the steel wheel roller was spread on the surface of the horizontal rolling, each time to meet the new layer propulsion 10 ~ 15 ㎝, until the new layer compaction, longitudinal normal rolling again, use 3 m straight edge check seam longitudinal roughness is in line with the requirements, otherwise shall be immediately removed redo, until qualified. Transverse joint should be from 20 ㎝, bridge expansion joints are not allowed in expansion joint, in order to ensure smooth on the surface of the expansion joint on both sides of the road.
Control of pavement flatness of modified emulsified asphalt
Before the construction, the quality defects of the asphalt mixture should be made up well, so as to ensure that the asphalt mixture is clean, free from sundries, smooth, without obvious local protrusions or low-lying areas. The flatness control in the construction should strictly prevent segregation of the mixture. The dumper should move according to the specified number of times when loading. The discharge port of the modified asphalt mixture storage warehouse should not be too high from the dump truck to avoid coarse aggregate segregation. The spreader shall be spread evenly, continuously and without interruption. The mixtures spilled in front of the spreader should be cleaned timely, and manual repair on the paved road is often counterproductive and ineffective. The speed of roller compaction should match the speed of paver. Pass to crush to maintain reasonable and effective, which should be followed, first, static pressure, vibration twice again, before the end of the static pressure two times five times principle, at the same time to solve the relationship between the glue roller and water isolation, to prevent excessive water caused by rapid cooling. In the process of crushing, the edge is pressed first, then the center of the road is gradually crushed. According to the roller compaction speed, number of times and overlapping width stipulated by the process, the initial pressure, the compound pressure and the final pressure are carried out.
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