Types and construction methods of road sealant
As an important component of preventive maintenance technology for asphalt pavement, the hot melt sealant technology has a relatively mature quality in foreign countries, but its price is expensive. Due to financial constraints in China, the selection of crack repair technology and repair materials is arbitrary, and related products often have poor low-temperature performance. In order to avoid repeated crack repair operations by highway maintenance departments, save a lot of manpower and material resources, and ensure the expected effectiveness of hot melt road sealant, hot melt road sealant has emerged in response to the current problems in the domestic hot melt road sealant market.
There are four commonly used types of hot melt sealant: high-temperature, ordinary, low-temperature, and severe cold. These four types are suitable for outdoor temperatures of 0 ℃, -10 ℃, -20 ℃, and -30 ℃, respectively. Customers can choose a suitable product according to their own needs, and the temperature or requirements can also be customized according to their needs.
Hot melt sealant construction method: mainly sealing road surface cracks by slotting and grouting, existing treatment methods - filling or grouting. The construction steps are: slotting, cleaning, and pouring (needle or adhesive sealing)
1. Preparation work
Check the slotting machine and filling machine to ensure their technical condition is good; Based on the specific situation of road surface cracks, determine the joint filling design scheme. Generally, the excavation width is 13cm~26cm, and the depth is 13cm~26cm (the ratio of width to depth is about 1:1 is optimal). Start the joint filling machine and add high polymer asphalt pavement joint filling adhesive to the heating tank. Heat and mix, and control the constant temperature to around 180 ℃, with a maximum temperature not exceeding 200 ℃
2. Slotting
According to the designed slotting size, pre adjust the depth of the slotting machine, and then proceed with the slotting operation.
3. Cleaning the groove
Use an air compressor or a backpack style hair dryer to thoroughly clean the debris and dust within a range of at least 10cm on both sides of the crack in the groove.
4. Grouting
The suitable temperature for road joint sealant is between 7 ℃ and 18 ℃. If the joint is repaired when the temperature is below 4 ℃, the joint sealant machine must be equipped with preheating equipment to preheat the slotted area. If the joint is repaired without preheating at this temperature, it will reduce the bonding force of the joint sealant; When the heating temperature of the sealant reaches around 180 ℃, use a pressure nozzle with a scraper on the sealant filling machine to evenly pour the sealant into the groove, and drag a certain width and thickness of the sealing layer on both sides of the crack; Due to the shrinkage of the volume of the sealant after cooling, in order to achieve the desired sealing effect, the method of injecting it back and forth twice can be adopted.
5. Maintenance
The newly filled road sealant should be sprinkled with dry fine sand on its surface. After the sealant is fully cooled and the road debris is cleaned, traffic can only be opened. The general cooling time is about 15 minutes, and the specific time can be flexibly controlled according to the temperature at that time.