Special for High Temperature And Rainfall Zones: 3 Core Construction Techniques for Pavement Crack Sealing Equipment

Special for High Temperature and Rainfall Zones: 3 Core Construction Techniques for Pavement Crack Sealing Equipment

Abstract

Road surfaces in high-temperature and rainy regions face severe dual damage: intense summer heat softens asphalt pavement, while frequent rainfall seeps into road cracks, erasing the base layer, triggering pavement subsidence, potholes and extended crack expansion. Pavement crack repair machinery (crack filling machine, joint sealer, road crack sealing rig) represented by the FND-TSG500 towable crack sealing vehicle is the core equipment for crack maintenance. Improper construction operation will directly lead to sealing glue detachment, water leakage and short service life of repaired joints. Combined with the performance characteristics of FND-TSG500 crack sealing trailer and the climatic characteristics of high-temperature rainy areas, this paper sorts out three indispensable core construction skills to improve the durability of crack sealing projects.

FND-TSG500 towable crack sealing rig

Side view of crack filling machine with slotter

1. Precise Temperature Control System Calibration, Adapt to High-Temperature Ambient Environment

High outdoor temperature in rainy zones will interfere with the heating balance of the crack sealing unit, resulting in two common construction failures: overheated sealing adhesive aging and insufficient heating of the delivery hose leading to material blockage. The FND-TSG500 road joint sealer is equipped with a dual digital liquid crystal temperature control box, which can separately monitor heat conduction oil temperature, hot-pour sealant temperature and heating hose temperature, and operators must calibrate temperature parameters according to on-site ambient temperature.

When the ambient temperature exceeds 32℃ in summer, the set temperature of the hot melt tank shall be reduced by 10–15℃ compared with normal temperature construction to prevent the sealant from thermal decomposition and loss of adhesion; the 6-meter electric heating delivery hose (longer than the conventional 4.5m pipe) needs to maintain a constant heating power of 1.5kW to ensure smooth material transportation in long-distance operation. The equipment’s circulating reheating system can circulate the molten sealant at the bottom of the kettle to the upper layer for secondary heating, which shortens waiting time for melting materials. In rainy weather with low air temperature, raise the heating power of the burner properly to keep the sealant in a stable flowing state, avoiding incomplete filling caused by cold glue solidification.

The 45° inclined geometric combustion chamber of this tow crack filler maximizes heat utilization without direct contact between flame and melting tank, effectively stabilizing heating efficiency under high-temperature outdoor conditions and avoiding local overheating of sealant.

2. Standardized Crack Slotting & Thorough Dewatering & Cleaning, Prevent Rainwater Hidden Danger

Rainy areas feature high underground water content and frequent sudden showers. The biggest hidden trouble of crack repair is residual water and dust inside slots, which will cause the sealant to separate from the pavement base after filling. The FND-TSG500 integrated crack sealing rig carries a self-mounted slotting machine with a 12V DC lifting winch (650kg lifting tension), which can be freely hoisted and dismounted, realizing integrated slotting and filling construction.

Step 1: Scientific slotting

For aged cracked pavement, use the matched pavement slot cutter to cut regular U-shaped grooves along crack trends. Narrow and shallow slots fail to form effective bonding surfaces, while over-wide slots waste sealant. After slotting, immediately remove all gravel and debris inside grooves with high-pressure air cleaning equipment.

Pavement slotting operation

High-pressure air cleaning of crack slots

Step 2: Complete dewatering treatment

This is the key skill exclusive to rainy regions. If construction is carried out after rain, operators must blow dry all residual moisture inside the slots with hot air blowers until the inner wall of the crack is completely dry. Even slight water stains will form a separation layer between asphalt and sealant. Do not start filling construction within 24 hours of heavy rainfall to guarantee long-term bonding performance of the joint sealant.

Step 3: Check slot cleanliness again

Re-inspect the groove before glue pouring to remove secondary floating dust blown up by wind, laying a solid foundation for tight combination between sealant and pavement.

3. Adjustable Flow Sealing & Full Depth Filling, Strengthen Anti-Seepage Capacity

High temperature accelerates the fluidity of hot-pour sealant, while rainwater impacts the joint surface continuously, requiring uniform and full filling without hollow gaps. The electric discharge gun fitted on the FND-TSG500 asphalt crack filler supports stepless flow regulation, which is the core tool to control filling quality.

First, adjust the discharge flow according to crack width: thin micro-cracks adopt low flow to avoid overflow waste; wide expansion cracks switch to medium-high flow to ensure full penetration of sealant to the bottom of slots. The external delivery pump design of the machine is easier to disassemble and maintain than submerged pumps, which reduces equipment downtime during continuous construction on rainy expressways and urban roads.

During filling, move the sealing gun forward at a constant speed, keep the nozzle close to the bottom of the groove, and fill from the bottom upward to eliminate air bubbles inside the joint. Avoid surface-only shallow filling, which will form hollow layers that rainwater can penetrate quickly. After filling, leave a slight convex arc on the surface of the crack, which can offset the shrinkage of sealant in high-temperature seasons and form a natural drainage surface to accelerate rainwater runoff and reduce water soaking time.

On-site crack sealing construction

Finished crack sealing effect

Conclusion

High temperature and heavy rainfall are the two major restrictive factors for road crack maintenance. Mastering temperature calibration, dry cleaning and flow-controlled full filling three core techniques can give full play to the advantages of the 500L large-capacity FND-TSG500 towable joint sealing machine, extend the service life of crack repair layers, cut repeated maintenance costs of highways, county roads and airport pavements, and effectively solve the long-standing water seepage and crack re-expansion problems in hot rainy areas.