Several methods used in repairing highway with joint filling machine
Expressway crack repair technology and cost analysis are introduced as follows.
I. crack repair technology and method
There are many methods to repair cracks. Generally, the repair process is determined according to the width and depth of cracks. According to the crack width, the cracks can be divided into four types
(1) micro cracks, which are less than 5 mm in width, have no or only slight cracks on the edge of the cracks, and have no or a small amount of supporting cracks, which have little impact on the stability of vehicle driving;
(2) small cracks, the width of which is 5-15mm. There are slight cracks at the edge of the cracks and a small number of supporting joints. There are a small amount of staggered platforms on both sides of the cracks, which will cause slight vehicle jumping;
(3) medium crack. The width of the crack is 15-25 mm. There are medium cracks at the edge of the crack, and there are a few supporting joints. There are a few staggered platforms on both sides of the crack, which will cause the vehicle to jump obviously;
(4) large cracks, the width of such cracks is more than 25 mm, the edge of the cracks is seriously cracked, and there are many supporting joints, and there are large staggered platforms on both sides of the cracks, which will cause the vehicle to run violently.
1. Slotting repair method
Slotting repair method is suitable for medium and small cracks, and is a general crack treatment method abroad. The equipment used includes slotting machine and joint filling machine. Sealant (modified asphalt polymer) specially designed for crack repair is used for joint repair. The groove size is at least 1 cm wide and 1 ~ 3 cm deep. The depth and width ratio of the groove should not exceed 2:1. The lower the depth ratio, the better. The construction process of slotting repair method is generally divided into five steps.
(1) preparatory work: check the slotting machine and joint filling machine to ensure that their technical conditions are in good condition; determine the joint repair design scheme according to the specific situation of pavement cracks; start the joint filling machine and add sealant to the sealant heating tank, heat and mix the sealant to 193 ℃, which can not exceed 204 ℃; During the heating period, the joint filling machine shall be towed behind the main vehicle, and the sealant, isolation pier, indicator plate, slotting machine, shoulder back type blower or hot air spray gun shall be installed on the main vehicle, and it shall be towed to the scheduled construction site, and half of the expressway half shall be closed as the construction area.
(2) slotting: according to the designed slotting size, the slotting depth of the slotting machine is adjusted in advance, and then the slotting operation is carried out. During operation, according to the type of crack width, timely adjust the slot size to meet the design requirements.
(3) groove cleaning: use shoulder back blower or hot air spray gun to clean the slag in the groove and dust within at least 10cm on both sides of the crack.
(4) joint filling: if the temperature is lower than 4 ℃, the joint filling machine must be equipped with preheating equipment to preheat the slotted part. If the joint is mended without preheating at this temperature, the adhesive force of sealant will be reduced; if the temperature is higher than 4 ℃, preheating is not required, and the effect of joint repair after preheating is generally better. When the heating temperature of sealant reaches about 1
93 ℃, the sealant is evenly poured into the groove by the pressure nozzle with a scraper on the joint filling machine, and a certain width and thickness seal layer is drawn on both sides of the crack.
(5) maintenance: after filling the joint with sealant, the traffic can be opened only after the sealant is fully cooled and the debris on the road surface is cleaned. Generally, the cooling time is about 15min. The specific opening traffic time can be flexibly controlled according to the temperature.
2. Non slotted repair method (traditional repair method)
According to the different materials used, this method can be divided into hot repair and cold repair.
Construction of heavy duty asphalt 1ah-110
Equipment: asphalt hot melting and spraying equipment (installed on engineering vehicle).
Then, it is necessary to clean up the asphalt cracks, and then to remove the asphalt cracks.
3. Cold patching construction of modified emulsified asphalt
Modified emulsified asphalt is a liquid mixed cold patching material, which has no special requirements for machinery and equipment. After mixing on site, the joint is manually scraped and coated (three coating).
Construction technology: preparation work → joint cleaning → mixing materials by workers → manual scraping once → curing → secondary scraping → solidification → three times scraping → solidification → traffic opening (curing time 15-20 min).
These traditional methods have been proved by many years of production practice that, no matter using heavy traffic petroleum asphalt or modified emulsified asphalt to fill the joint, with the temperature shrinkage of the surface layer and base course, the cracks after maintenance will crack again at the original grouting joint position, and the failure rate accounts for more than 86%, so it has to be repaired in the second year. Such regular maintenance not only increases the maintenance cost, but also causes many inconveniences for driving.
Therefore, the main performance of the sealant is the construction environment and temperature.