Underwater Concrete

The construction of a wide range of structures including bridge, dam, canal and river defences has driven the need for underwater concrete.

RMX UW is our specialist underwater concrete; designed combining a range of SIKA admixtures to set almost instantly underwater.  The concrete is pumped out like ‘squirty cream’ using a concrete pump or tremie pipe and care must be taken to minimise washout and segregation.


This product is suitable for:



  • Rapid setting mix
  • Strength/density can be adjusted
  • For use in still and flowing water conditions


  • Minimised washout
  • Easily placed either by concrete pump or tremie pipe
  • Reduced risk of contaminating waterways
  • Conforms to BS 8443

Reinforcement Options

For increased strength and improved crack resistance we can offer Reinforced Concrete.  Refer to the technical download sheet or contact our team for more information.

Environmental Solution

RMX UW concrete can incorporate a proportion of GGBS, a cement replacement material that generates a much lower level of embodied CO2 emissions than ordinary cement, minimising environmental impact.

Case Studies

RMX UW - Underwater Concrete

Colne Bridge Lock – RMX UW Concrete