Geogrid construction technology
Release time: 2016-04-13 22:40 1476 views
I. Construction method of steel plastic geogrid:
1. The laying surface of the geogrid should be relatively flat. After passing the laying experience, in order to prevent longitudinal skew, first draw a white line or hanging line on the laying layer according to the width, and then start laying, and then use U-nails Fix the end of the grid (4 nails per meter wide, fixed at a uniform distance);
2. After the end of the grille is fixed, use a laying machine or manual method to slowly pull the grille forward. Manually survey each 10m long until one roll of grille is finished, and then roll the next roll. Same operation as before;
3. Spreading: take the length of the roll as the length of the laying section. After the length of the grid should be covered, check the overall quality once, and then lay the next section. When the next section is laid, the grid and grid are laid. The grid is overlapped by a grid with a clear distance as the overlap length, and is fixed with a tie wire to continue to pave the second section in the forward direction. By analogy, the operation requirements are the same as before.
Construction method of two-way plastic geogrid:
1. When the two-way plastic geogrid is used for subgrade and pavement, excavate the foundation bed, set up a sand cushion layer (with a height difference of not more than 10cm), roll it into a platform, and lay the grid. The longitudinal axis should be in line with the main force direction Consistent, overlapping 15-20cm in length and 10cm in width. The overlap is tied with plastic tape and fixed to the ground with U-shaped nails every 1.5-2m on the laid grid. The geogrid laid should be backfilled in time. Material, the number of geogrid layers laid depends on technical requirements.
Construction method of glass fiber geogrid
1.There are currently two types of glass fiber geogrids, fixed and self-adhesive.
Fixed fiberglass geogrid reinforced asphalt concrete pavement usually adopts anchoring method. The materials and procedures used in this method are as follows:
A. The fixed iron sheet of 50 × 50 × 0.3mm is required to be flat without warping, and the surroundings should be chamfered. 2 inch steel nails (high-quality cement nails).
B. AH-70 or AH-90 heavy oil hot asphalt shall be used as the sticky layer oil. The specifications and quality of the sticky layer oil shall conform to the regulations "Technical Specifications for Highway Asphalt Pavement Construction" JTJ032-94.
C. When laying the glass fiber geogrid by nail fixing method, first fix one end with the fixed iron sheet and nail on the substructure that has been sprayed with adhesive layer of asphalt. The nail can be shot with a hammer or a shotgun, and then the grid is pulled longitudinally. Tight and fixed in sections, each section is 2 to 5m in length. For cement concrete pavements, it can be divided according to the shrinkage gap. The position of the nails is set at the joints.
D. Roll with a rubber roller.
E. The nail fixing position is shown in the figure. The grid overlap distance is: vertical overlap distance of 10 to 20mm, horizontal overlap distance of 10 to 15mm, and the vertical overlap should be based on the asphalt paving direction. Frame above.
F. When fixing, do not nail the glass fiber, or directly hit the glass fiber with a hammer. After fixing, if you find that the nail is broken or the iron sheet is loose, you need to fix it again.
G. In order to prevent the tires of the construction vehicle from sticking the glass fiber grid and the sticky layer and the asphalt concrete paver wheel slipping, the stone surface of the sticky oil should be dusted with the amount of 3 cubic meters / 1000 square meters to 5 cubic meters. 1000 square meters, atmospheric temperature is less than 10 ℃ or road construction is not allowed.
H. After laying the fiberglass geogrid, strictly control the access of the vehicles carrying the mixture, and prohibit the vehicle from turning, braking, and dumping the scraps of the mixture on the grid layer to prevent damage to the grid. On the same day when the grid is laid, all fiberglass geogrids must be covered with asphalt concrete on that day to prevent vehicles from directly causing damage to the fiberglass geogrid.
Self-adhesive glass fiber geogrid direct laying method
A. Use the old asphalt concrete pavement and old cement concrete pavement to make a leveling layer with a thickness of 20mm to 30mm. Use a vacuum car or a sprinkler to ensure the road surface is clean.
B. Spray AH-70 or AH-90 heavy oil hot asphalt, the dosage should be 0.3kg ～ 0.4kg / m2
C. Use a special paving car to lay the self-adhesive glass fiber grid. The laying should be smooth and tight.
D. The length of the horizontal overlap should be 50mm ～ 100mm, and the length of the vertical overlap should be 150mm ～ 200mm. The direction of overlap overlap is the same as that of the asphalt concrete paver.
Geogrid construction process:
Process flow: detection and cleaning of the lower supporting layer → manual laying of the geogrid → overlap, lashing, fixing → paving of the upper subgrade soil → rolling → inspection.
The geogrid is laid on the flat lower bearing layer with the width required by the design. The upper and lower layers of the filler are free of debris that punctures the geogrid. When laying the geogrid, the direction of high strength is arranged perpendicular to the axis of the embankment. The geogrid is laid horizontally. Tighten and stretch when laying to avoid wrinkles, distortions or potholes. The geogrid is spliced in the longitudinal direction by the overlap method, and the overlap width is not less than 20cm.
After the geogrid is laid, the upper layer of filler is manually laid, and rolling is completed in time to avoid long-term exposure. Then use mechanical conveying, leveling and rolling. The mechanical paving and rolling are advanced from both sides to the middle, and the rolling is performed from both sides to the middle, and the compactness is maintained to meet the specifications.
Prevent all construction vehicles and construction machinery from driving or parked on the paved geogrid. During the construction, check the quality of the geogrid at any time. If you find any damage such as breakage, puncture, tear, etc., repair or replace it according to the degree.