Track Slab PU Grouting in China

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Project reference basis. Figures and configuration details are reported in the supplied project brief. They are reference values for the stated application, rather than verified acceptance results or a guarantee for another installation. Confirm the source records, material, tooling, operating schedule and test method when assessing a comparable project.

A tier-one national railway engineering contractor deployed Haifeng’s automated mobile track slab grouting systems to construct continuous damping cushion layers for a newly built 350 km/h high-speed railway line. The project required filling the sealed cavity beneath CRTS III ballastless track slabs (each measuring 5,600 mm in length and 2,500 mm in width) with an engineered microcellular polyurethane formulation.

Prior to the deployment, the construction team faced significant quality hurdles with standard low-capacity dispensing equipment. The low discharge rate (less than 15 kg/min) allowed the fast-reacting resin to build viscosity before reaching the farthest edges of the 5.6-meter cavity, causing trapped air pockets and cold knit lines. Ultrasonic non-destructive testing revealed internal void defect rates of 8.5%, risking premature cushion settlement under cyclic train loads.

Haifeng supplied two heavy-duty mobile grouting skids mounted on flatcar trailers, engineered with high-displacement dynamic mixing technology. Capable of delivering up to 60 kg/min, the systems enabled rapid, uninterrupted laminar filling across the entire cavity before the onset of chemical gelling, ensuring compliant ballastless track installation.

Haifeng engineered and delivered an all-weather, vehicle-mounted track slab grouting package designed for active railway construction corridors. The equipment was integrated on flatcar trailers equipped with onboard auxiliary diesel generators, providing autonomous power across remote viaduct sections.

The system features dual 300 L jacketed day tanks with active electric heating to maintain resin components at 35°C despite freezing outdoor morning conditions. Rotary gear metering pumps driven by synchronous servo motors meter the polyol and isocyanate streams via continuous Coriolis mass flow measurement.

Material is delivered through 25-meter heated delivery lines to an articulated boom supporting the dynamic mixing head. Technicians dock the quick-release grouting flange onto the central filling port of the track slab. The system automatically injects 120 kg of polyurethane slurry in just 3.5 minutes under a controlled 0.15 MPa backpressure. As resin vents through inspection ports at all four corners, the pneumatic cutoff valve engages instantly, executing an air-blast purge cycle that prevents line plugging.