Layout construction method of hot melt marking line (1)
Release Time：2019-07-11 08:41:47
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At present, hot-melt coatings are mainly used for marking high-grade highways in China. Hot-melt paint marking is widely used in road design because of its fast drying, good reflective effect, beautiful appearance, strong wear resistance, relatively long service life and moderate cost. It is the main form of road marking in China at present. The laying-out construction method of hot melt marking line has been used more and more in the construction of hot melt marking line of expressway.
I. Characteristics of Construction Law
In the past, hot melt paint marking construction lofting mainly used the method of throwing big rope, which was slow in progress and easy to deviate the line shape. The main technical indicators were difficult to guarantee, the investment of manpower was more, the efficiency was lower and there were many potential safety hazards. The use of waterline lofting construction method could ensure the horizontal deviation of the marking line and reduce the number of markers in rainy season. The influence of the period reduces the labor intensity of the cleaning work, reduces the construction personnel, improves the work efficiency and ensures the construction quality.
II. Scope of application
It is suitable for hot-melt paint marking construction of all asphalt and cement concrete pavement with a length of more than 10 km and two or more longitudinal marking lines.
3. Technological Principle
Based on the principle of parallel line, the datum line, i.e. water line, is drawn with white dilute material at the corresponding position of pavement marking line. The water line is laid with water-soluble and environmentally friendly civil interior wall paint. The water line can be distinguished clearly within two months under the erosion of rainwater, and can be separated by itself under the rolling of vehicles after opening to traffic. Fall, leave no permanent trace. After checking the alignment and size of the waterline, we can use the waterline as the benchmark to lay out the marking line after meeting the requirements, which reduces the number of layouts, ensures the width of the lane, reduces the probability of errors, reduces the impact of climate on the marking construction, enhances the pre-control effect of the marking line and improves the work efficiency.
IV. CONSTRUCTION TECHNOLOGY
(1) Lofting:
Layout of marking line is a key process, which plays a decisive role in the alignment, so the application of the process of laying out of marking line
The squad leader must be experienced technicians, familiar with the principles of marking design, and skilled in the operation of various measuring equipment 1 and datum point determination.
Layout of marking should first measure the central point of the road and then determine the central line according to the specifications, but it can not be done in practical work. The reasons are as follows: new roads generally require the completion of marking of the road surface, hard shoulders often lag behind paving, road edge lines are not well defined, according to design and specific. There are deviations in the construction, which do not have the conditions to accurately determine the center line of the pavement. Therefore, the following methods are used in practical work:
A road with a medium section of road or separated subgrade section shall first check the width of the road surface and then divide it into two sections.
The lateral position of each marking line on the road surface is determined by pushing the edge of the shoulder with or on the left side outward according to the design requirement; the road without middle zoning is checked to determine the width of the road surface, and then the center line of the road surface is determined by taking the center value, and the transverse position of each marking line on the road surface is determined in turn. If the horizontal position of the marking line meets the design requirements, it should be positioned accordingly. If it does not meet the design requirements, the reasons should be found out and the setting-out position should be adjusted. The principle is to ensure the lateral width and the net Lane width.
The location of the edge marking near the middle zone can be determined by the completed curb stones, but the position of the pavement and curb stones should be checked in order to prevent errors in the pavement units. Because once the markings are coated, it is almost impossible to make large-scale changes, especially on asphalt concrete pavement. So the marking position must be accurate. Check carefully during construction lofting. If there is any discrepancy with the drawings, report it to the supervisor and the owner immediately and negotiate with them. Don't neglect this work because of time constraints and easy shutdown.
If the above conditions are not met, the central line shall be determined strictly according to the central point of the road.
2. Layout of working line of water line
The first step is to mark the position of the marking line edge on the road surface every 10m-30m, minus the working width (5cm-10cm) of the marking line. The second step is to connect each point with a flexible rope to produce a smooth curve or straight line (the points are not necessarily all on the line). Set up the working line of the water line.
3. Waterline lofting:
The water line is drawn by the water line vehicle based on the released water line. Waterline truck is a small truck with 0.75T water frame, water line pointer and water line self-flowing device. Drivers of water-line vehicles drive water-line vehicles smoothly and uniformly along the working line, and they must keep the water-line pointer always coinciding with the water-line working line. Based on the principle of parallel line, a fixed distance flow nozzle is set on both sides of the waterline vehicle, and its spacing is the construction width of two markings. The self-flow nozzle adopts gas cutting nozzle, whose lower edge is about 3 cm away from the road surface, to prevent the influence of wind and small stones on the water line. A special person-controlled self-current switch is set up on the waterline vehicle, and the corresponding waterline with a width of 0.3cm-0.5cm is drawn when the waterline vehicle is moving by using the siphon principle. Water-line materials are laid out with water-soluble and environmentally friendly civil interior wall paint, which ensures that the water line remains clear and identifiable within two months under the erosion of rainwater, and ensures that the water line can fall off quickly and automatically without leaving permanent traces under the rolling of vehicles after opening.
The water line serves as the datum line for marking. The nearest water line to the working line should be kept 3cm - 5cm away from the working line to ensure the clarity of the water line. Drivers of water-line vehicles need rich construction experience to ensure smooth running of water-line vehicles. Construction personnel who control the self-current switch should open and close the vehicle in time when it starts and stops.