Crack Sealing Machine Product

Overview

A crack sealing machine injects hot bituminous sealant into longitudinal and transverse cracks in asphalt pavements, slowing water intrusion and delaying pavement deterioration. The machine is towed on a two-wheel trailer, powered by household or site power, and operated by a single technician walking behind the machine with a handheld Injection Wand & Hose. It is maintenance-intensive and labor-focused, used on secondary roads, parking lots, and minor streets where capital equipment investment is minimized.

The sealant is typically a polymer-modified bitumen that flows hot (150–180 °C) but remains flexible after cooling, stretching with the pavement as thermal stress cycles expand and contract the cracks.

How it works

The operator fills the Sealant Tank Assembly with sealant from a heated supply truck or drum. The Burner & Heating, fired by diesel or propane, heats the sealant to the working temperature (typically 160–170 °C), controlled by the Temperature Thermostat. The Agitator Shaft and Agitator Blade gently stir the sealant at 10–40 rpm to distribute heat evenly and prevent settling of polymers or mineral fillers.

When ready to work, the operator plugs the Pump Drive Motor (typically a 110V or 220V electric motor, or a small gasoline engine) into a site power outlet or generator. The motor spins the Gear Pump, a gear pump rated for hot, viscous sealants. The pump draws sealant from the tank bottom through a Suction Strainer and pushes it out at 10–15 bar through the Delivery Hose coiled on the Hose Reel Assembly.

The operator unwinds the hose (hand-pulled from the reel, or mounted on a reel cart) and positions the Injection Nozzle over the crack. The nozzle orifice is adjustable (3–6 mm) to meter the sealant flow. Squeezing the Trigger Valve opens the valve in the wand, releasing sealant into the crack at a controlled rate.

The operator walks backward along the crack, maintaining constant wand speed and keeping the nozzle centered and close to the surface (typically 3–5 mm away). The hot sealant fills the crack cavity and extends slightly above the surface, creating a raised bead that is smoothed level with the pavement after cooling. Typical fill rate is 200–500 m of crack length per hour, depending on crack width, sealant viscosity, and nozzle speed.

The Pressure Relief Valve protects the system from overpressure — if a crack is too tight or the nozzle becomes clogged, pressure rises to 15 bar and excess flow vents to tank. The System Pressure Gauge on the Control Panel & Gauges allows the operator to monitor system health and detect blockages.

The Temperature Display displays tank temperature, allowing the operator to verify that the sealant remains in the workable range. Temperature drift is managed by the Temperature Thermostat, which cycles the burner on and off to maintain set point. Sealant that is too cold becomes thick and difficult to inject; too hot oxidizes and loses flexibility.

After a few hours of work (or when the tank is depleted), the machine is shutdown. Any residual sealant in the hose and nozzle hardens as it cools; cleanup is typically performed by flushing with kerosene or diesel, then manually scraping hardened bead from the nozzle before storage.

The towing vehicle tows the trailer to the next site. The Towed Trailer Chassis is light enough (empty weight ~1,000 kg, loaded ~3,500 kg) to be towed by a ½–1 tonne pickup truck, making the whole operation mobile and cost-effective for maintenance work on a city road network or campus.

Typical daily production by a two-person crew is 1–3 km of cracks sealed, equivalent to 3–10 lane-km (accounting for lane width and crack spacing). A skilled operator can achieve production rates of 500–800 m/day, the speed limited by hose management, nozzle positioning, and the need to maintain steady wand speed over varying surface conditions.