Preventive maintenance of highway cracks, do not despise!!
Cracks are common diseases of pavement. If cracks are not handled in time, rainwater will enter the surface and base through cracks. Under the action of vehicle load, dynamic water will wash away the structure layer, resulting in water damage such as slurry or loose base, which will eventually lead to pavement cracks, pits and other diseases.
One of the common ways to deal with cracks is to repair cracks.
Grouting is an effective preventive maintenance measure, and the purpose of filling is waterproofing. Grouting joint can prolong the service life of asphalt pavement, and the construction cost is low, only 1/6 of the cost of digging and repairing the pavement.
What are the ways to repair cracks?
1. Road sealant material
1. The sealant is a composite material of solid modified asphalt and thermoplastic rubber. It has fast hot melting, strong adhesion and good deformation resistance and recovery performance. Compared with other types of sealants, this type has the characteristics of low consistency and easy penetration into various fissures. In summer, its high temperature softening point can reach 96 C; in winter, its low temperature resistance can reach approximate - 32 C, so it is more suitable for temperate environment with large temperature difference span. The sealant has strong bonding ability with seam wall, does not adhere to wheel at high temperature, does not brittle crack at low temperature, and has good durability.
2. Special equipment
BEST-GTMM150 slotting machine
BEST-GTBB500 seaming machine
3, process flow
(1) grooving
According to the crack marking, adjust the slotting width and depth of slotting machine, and cut the uniform U-shaped groove in the center line of the crack. The ratio of depth to width should not exceed 2:1. The slotting should be at least 1 cm wide and 1.2 cm deep.
(2) cleaning up
Clean up the residue in the cracks and ensure the solid bonding between the sealant and the seam wall.
(3) irrigation joints
The special sewing machine is used for the operation. In order to prevent the wheel from sticking to the glue, sometimes it is necessary to sprinkle the sealant and sprinkle it with sand.
(4) maintenance and repair
After completion of the crack filling, the traffic will be cooled after 10~20min cooling according to the temperature.
Two, cold fill irrigation sealant has two kinds of asphalt and silicone.
BEST cold patching sealant is a one-component cold patching emulsified asphalt crack sealant treated with rubber. It is designed to fill cracks of 12 mm wide on highway surface. BEST cold patching sealant is an environmentally friendly water-based crack sealant with VOC less than 150 grams per liter.
BEST silicone sealant is an ointment-like material that solidifies into a tough rubber-like solid once exposed to moisture in the air. It is mainly divided into deacetic acid type, dealcoholation type, deamination type and deactivation type. It provides a protective barrier for cracks to prevent moisture from entering the road surface.
Cold patching sealant (asphalt)
Cold patching sealant (silicone)
Technological process:
(1) clean the inner side of the crack and keep it dry to ensure the solid bonding between the sealant and the seam wall.
(2) directly pour cold sealant into the joint and scrape it with rubber scraper.
(3) after the completion of the crack filling, according to the temperature, 10~20min will be opened and traffic will be opened.
Three. Sewing tape
Joint strip of asphalt pavement is a rolling anti-cracking and waterproofing diaphragm. After the thickness is about 2-2.5mm, the polymer waterproofing film is coated on the 0.3mm thick anti-wrinkle and anti-heavy-load polypropylene material. After rolling and compounding, the outer side is a three-layer waterproofing film material. Because of the good stability of the material itself, the tensile strength of the joint strip is high, and it has strong cohesion. Force, fully integrated with the road surface, effectively prevents crack expansion and rain water immersion, thus reducing road surface damage, thereby prolonging the service life of the road surface.
1, the scope of use
It is suitable for preventive maintenance of asphalt pavement surface cracks, and the crack width is below 5mm. If the width of the seam is greater than 5mm, the bitumen should be first filled and then the tape should be used.
Four, how to see the effect of irrigation joints?
The following is a comparison map:
Failed irrigation cases:
Open traffic is too early. The sealant is swept away by the tire.
Tear of seam wall
Successful case:
Slit heart language
(1) construction temperature: construction temperature is one of the causes of sealant falling off.The moisture and temperature below 4 degrees will reduce the cohesive force of the sealant and fall off easily.The overall temperature of the pavement is lower. After sealant filling, the temperature drops faster, the sealant shrinks obviously, and the temperature stress between sealant and groove wall is larger, which will reduce the bonding force between sealant and pavement.
(2) Crack humidity: When filling joints, the pavement should be dry. If it is wet, the bonding force between sealant and pavement will be reduced and some sealants will fall off.
(3) Keep clean: Before filling the cracks, clean the dust and debris in the cracks after grooving and loose objects around them with air compressor, and keep the cracks clean.
(4) Grouting range: It is inappropriate to use this method to deal with cracks, especially on pavement with serious rutting, which forms net cracks.
Five. The cold patch sealant has the following advantages compared with road sealant and adhesive tape.
1. Easy to operate.
The use of pavement cold filling seam glue does not need to slot, only need to clean up the cracks, direct jointing ordinary workers can master the construction skills in 5 minutes.
2. Construction speed is fast.
The speed of pavement crack cold filling treatment is faster than that of sealant filling. As long as the crack periphery is cleaned, the filling can be carried out. The construction intensity of workers is reduced and the construction efficiency is improved.
3, quality and environmental protection, beautiful and durable
BEST cold filling glue is an environmentally friendly water-based crack sealant. The VOC content per liter is less than 150 grams. It also has good penetrability and strong cohesive force, and the reflection cracks caused by the base layer can also be disposed.
In a word, the application of filling joints in asphalt concrete pavement maintenance embodies the tenet of "prevention first, prevention combined", which is a scientific maintenance technology to effectively prolong the service life of pavement. With the continuous popularization and application of cold filling seam glue in crack treatment, good economic and social benefits will be further achieved.