The hazard of road cracks lies in water seeping into the subgrade through the cracks, which softens and damages the roadbed, leading to a decrease in road-bearing capacity, the formation of pump slurry and network cracking, and accelerating the degradation of the road surface. If road cracks are not promptly treated with materials such as crack sealant or crack tape, and the subgrade is infiltrated by rainwater or snowmelt, long-term vehicle traffic will cause the subgrade to erode and the structure to sustain severe damage, significantly reducing the service life.
The role and characteristics of transportation roads determine the importance and uniqueness of highway maintenance and management. Ensuring effective maintenance of highways is a long-term and challenging task. Currently, there are numerous methods for repairing concrete road cracks. Next, we will focus on one of the main materials used in the repair of cement concrete road cracks: crack filling adhesive.
Sealant for Joint Filling
[Sealant Composition] The sealant is a single-component, new type of oil-based cold-applied sealant material. This material is a flexible one with special anti-displacement and waterproof properties. It absorbs moisture from the air to cure, demonstrating strong weather resistance. After curing, it will not flow even under high temperatures or when damaged, and will not crack even at temperatures below -20°C. It can be used for construction between 50°C and -25°C. The material will not peel off before or after rain and maintains its elasticity. The color of the sealant is usually gray, suitable for cement concrete road cracks and expansion joints.
[Sealant Properties] Single-component, ready to use after opening, self-leveling in liquid state at room temperature, no additional operation required, color is generally gray.
[Application Range] Adaptable for asphalt concrete pavement cracks (mainly using asphalt crack filling sealant for higher cost-performance), surface cracks in cement concrete pavements, suitable for expansion joints, settlement joints, cutting joints, and construction joints of newly paved cement pavements in squares, airport runways, roofs, and basements, etc., for bonding and sealing of disease cracks (and) joints.
[Key Features] Simple crack filling process, ready to use upon opening (with a dedicated injection nozzle), rapid curing time, immediate traffic reopening, high bonding strength and good flexibility after curing. Suitable for application from -20°C to 80°C, excellent resistance to acids and alkalis, waterproof, oilproof, and dustproof. Resists humidity and aging. Features good tensile, compressive, and bonding strength.
[Usage Instructions]
1. Cleaning: Remove all debris from cracks wider than 3mm prior to filling, using a metal hook to clear out any dirt inside the cracks. Ensure both the cracks and their sides are clean of any dirt, dust, fragments, or weeds.
2. Cracking: For cracks less than 3mm wide, use a crack widening machine. The widened crack width is generally 4 to 6mm, and the depth is 6 to 10mm.
3. Dust Removal: Utilizing a dust removal machine to ensure thorough cleaning of floating dust, followed by using an elastic steel brush to remove loose concrete debris left in the gaps after expansion.
4. Filling: For wider and deeper cracks, fill the cleaned crack with gravel or elastic foam strips with a particle size larger than the crack width before injecting the sealant. Leave a space of 0.5-1cm above for the sealant application.
5. Injection Molding: For cracks less than 3mm wide, use a crack widening machine to expand the crack before injecting the sealant. The ideal width and depth after widening should be 6-8mm. (The reason for widening is that the inherent surface tension of the sealant cannot achieve self-leveling of the gel due to the small width of the crack, thus it cannot be smoothly injected into the crack.) After widening, each kilogram of sealant can fill 20-30 meters of crack. For cracks wider than 3mm.
6. Concrete pavement construction joint sealing: After cutting, the joint width is generally 1 cm and the depth is 7 cm. During the sealing process, sand or elastic foam strips can be used to fill the cracks. Leave a space of 0.5 cm above for the sealant. Each kilogram of joint sealant can seal a joint for 15 meters.
7. Open Traffic: The surface drying time of the crack filling adhesive is less than 1 hour at temperatures above 15°C; the drying time is relatively extended at temperatures below 15°C. For cracks less than 1 cm wide, traffic can be reopened directly after injection.
