Inflatable Rubber Culvert Balloon for Structure Weight Reduction

Inflatable rubber culvert balloon, also called inflatable rubber core mold or inflatable rubber formwork, which is to form cavities for large reinforced concrete structures including bridge, tunnels, roof, stake, roof board column, beam, building construction, irrigation works and water conservancy projects, etc. In this way, 20% weight of building structure is reduced than those with solid concrete structures. Meanwhile, inflatable rubber culvert balloon shorten the pipe foundation, increase span as well as provide a simpler and safer construction.

Inflatable rubber culvert balloon can be divided into many kinds according to its shape: round, rectangle, octagon, hexagon, trapezoidal and so on. And round inflatable culvert balloon and octagonal inflatable rubber culvert balloon are common used in most projects.

Three cylindrical inflatable rubber mandrels

Inflatable rubber culvert balloon


  • High strength to withstand the pressure of concrete when the mandrel is inflated.
  • Quality synthetic rubber and natural rubber materials make the mandrel durable, long lasting, flexible and elastic.
  • Save materials, time and efforts.
  • Soft to fold, curly, contract and store.
  • Various shapes including round, oval, rectangular, vaulted, trapezoidal, etc.
  • Great resistance to aging and bulge.
  • Wide applicable temperature ranging form 10°C to 90°C.
    A plan about ten shapes of inflatable of rubber mandrels

    Shapes of inflatable rubber culvert balloon

  • Easy and convenient to operate - only place mandrels into negative reinforcement cage, inflate them to appropriate work pressure, pour concrete and deflate the mandrels until the concrete is solid, then pull the capsule out.


  • Diameter: 9mm to 28000mm.
  • Total length: 0.8m to 35m.
  • Other specifications are also available upon customers’ requests.


Items Index
Thickness of rubber and fabric, mm 2.4mm - 15mm
Hardness(Shore A) 65 ± 5
Adhesive tension of rubber and fabric, N/25mm ≥8
Tensile strength, MPa ≥12
Elongation at break, % ≥350
300% Stretch set length, MPa 6
Stretch for deformation ratio ≤20 % (Prevent distortion)
Suitable temperature, °C -10 to 80
Appearance No cracks, no bubbles on the surface, the length of impurities trace is not more than 3mm, the depth is not more than 1.5mm, and quantity of the trace is not more than one. The deformation is not more than 2mm.

The structure of inflatable rubber culvert balloon : the normal types of inflatable rubber culvert balloon are one fabric two rubber and two fabric three rubber. What’s more, we can also produce other types of inflatable rubber culvert balloon according to customers’ requirements.

The specific structure of inflatable rubber mandrel.
Inflatable rubber culvert balloon structure.

The inflatable rubber culvert balloon products have many fittings, such as air value, pressure gauge, glue and tire piece.

An air value is on the table.

Air value

A pressure gauge is on the table.

Pressure gauge

A heap of inflatable rubber mandrel fittings are on the table, including air value, pressure gauge, glue and tire piece.

Inflatable rubber culvert balloon fittings.

Two inflatable rubber mandrels are mounted before concreting.

Mounted inflatable rubber culvert balloon before concreting.

Five inflatable rubber mandrels form cavities after concrete.

Inflatable rubber culvert balloon form cavities after concreting.

Inquiry for Our Product

Zaoqiang Dacheng Rubber Co., Ltd.
E-mail: info@marineairbags.com

When you contact us, please provide your detail requirements.
That will help us give you a valid quotation.