What are the weather requirements for geotextile construction?

Geotextile construction has certain requirements for temperature and precipitation.

Geotextile, also known as geotextile, is a permeable geosynthetic material made of synthetic fibers by needling or weaving. Geotextile is a new type of geosynthetics. The finished product is cloth-like, generally 4-6 meters wide and 50- 100 meters long. Geotextiles are divided into woven geotextiles and nonwoven geotextiles.

Construction procedure of geotextile repairing old asphalt pavement

First, the old pavement treatment

1, dust, loose particles and sundries should be removed from the old pavement, cleaned and the surface should be kept dry. Sharp and steep parts of the road surface should be leveled; For severely damaged and damaged pavements, the damaged parts should be removed and repaired with asphalt concrete. For pavement with serious cracks or rutting, a leveling layer of 1 ~ 2 cm should be paved.

2. Sprinkle asphalt binder oil

When liquid petroleum asphalt is used as viscous layer oil, the atmospheric temperature is above 5℃; When emulsified asphalt is used as binder oil, the atmospheric temperature is above 10℃. In rainy days and when the road is wet after rain, it is not allowed to stick oil backwards. Attention should be paid to selecting the variety and dosage of viscous oil. Practice has proved that it is best to use EVA or SBS modified asphalt. These products have good crack resistance and thermal stability. If emulsified asphalt is used, its asphalt content must be greater than 60% to make full use of it.

Before laying geotextile, spray asphalt adhesive layer for pumping, and the dosage is about 0? 4~0? 6kg/m2, then spread geotextile, and then sprinkle a layer of the same type of adhesive oil on the geotextile, with the dosage of 0? 5~0? 6 kg/m2. The following points should be noted: (1) It is recommended to use hot asphalt laminated sleeve, and the oil temperature should be kept between 150 ~ 170℃; ⑵ The lateral range of gunning oil is 5 ~10 cm wider than geotextile; (3) Viscous oil should be sprayed evenly and measured accurately.

If the oil is poured once, the total amount of rubber layer oil cannot be reduced, and the recommended value is 1? 0~ 1? 3kg/m2, the oil temperature should not be lower than 180℃. Once the oil is poured, it is easy to cause the geotextile to be impermeable and delaminated, resulting in the surface layer peeling off.

Second, the laying and overlapping of geotextile

1. Geotextiles shall be installed mechanically or laid manually. When laying, pay attention to make the rough singeing surface face up, then fix one end with a fixer and tighten it mechanically or manually. The tensile elongation is about 1? 0%~ 1? 5%, flat and close to the road.

The fixer comprises a fixing nail and a fixing iron sheet. The fixing nail should be cement nail or nail shot, and the length of nail shot is 8 ~10 cm; The fixed iron sheet can be made of iron bars with a thickness of 1 mm and a width of 3 mm.

2, geotextile transverse lap about 4 ~ 5 cm, according to the paving direction, the back end under the front end, and hot asphalt or emulsified asphalt cementing, fixed with a fixer; The longitudinal lap joint is also about 4 ~ 5 cm, which can be directly bonded with adhesive oil. When the lap joint is wide, the interlayer at the lap joint becomes thicker, and the bonding force between the surface layer and the base layer is weakened, which easily leads to adverse effects such as bulging, falling off and shifting of the surface layer. Therefore, the wide part of the knee should be cut off.

3, geotextile should be paved in a straight line as far as possible. When turning is needed, cut off the bend of the fabric, cover it, and spray adhesive layer oil for bonding. If wrinkles appear during laying, fabric wrinkles should be avoided as much as possible (wrinkle height >; 2cm), you have to cut this part of the fold, and then overlap it along the laying direction and hand it over with adhesive oil.

4. When laying geotextile, after spraying asphalt adhesive layer oil for the second time and cooling for about 2 hours, appropriate amount of yellow sand should be sprinkled in time to prevent the cloth from being lifted or damaged due to the oil adhering to the wheels when the vehicle passes on the geotextile. The dosage of fine sand is about 1 ~ 2kg/m2.

Third, the asphalt surface construction

1. The construction method of asphalt pavement is the same as that of ordinary asphalt pavement. The design of pavement structure and thickness shall adopt the methods specified in specifications for design of highway asphalt pavement (JTJ0 14) or Technical Specification for Highway Maintenance (JTJ073). The thickness of asphalt overlay on old asphalt concrete pavement is generally 4 ~ 6 cm.

When paving asphalt mixture, the paving temperature must be strictly controlled!

If the temperature is too high, concrete will burn easily. The temperature is too low, which affects the compactness.

2. Road compaction treatment

Pavement compactness is very important to pavement quality. Insufficient compaction of pavement will lead to cracking, looseness and rutting, which will seriously affect the service life of pavement.

Fourth, the construction matters needing attention

1, vehicles should try to avoid turning or braking on geotextile, especially when paving asphalt pavement, any sharp turning or sliding can bring up or destroy geotextile.

2. Construction under rainy, humid or cold weather conditions will affect the bonding strength and coating effect of the coating.

3. Traffic must be closed during laying. Except for construction vehicles, other vehicles are only allowed to pass through geotextiles in an emergency.

4. If the paver slips when paving hot-mix asphalt mixture, a small amount of stone chips can be sprinkled on the surface of adhesive layer oil.

Generally speaking, when we master the construction points of geotextile skillfully, we can make it play a greater economic benefit and make greater contributions to our urban construction.