A free flowing or pumped, non-shrink cementitious grout for use underwater or in tidal zones where 'wash out' would be a problem with conventional grouts. It is a blend of Portland cements, graded fillers and chemical additives, with the aggregate grading minimizing segregation and bleeding whilst assisting flow characteristics. It conforms to the requirements of BS EN 1504-3 Class R4 and is suitable for stanchion base plates, bridge columns, quay pillars, concrete piling and slipway applications.


  • Chloride free.
  • Displaces water effectively.
  • Exceptional resistance to freeze thaw.
  • Gaseous expansion system compensates for shrinkage and settlement in the plastic state.
  • High early and ultimate strength.
  • No risk of significant “wash-out” of cement phase when placed under water.

General information


Chloride free

Displaces water effectively

Exceptional resistance to freeze thaw

Gaseous expansion system compensates for shrinkage and settlement in the plastic state

High early and ultimate strength

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Uniclass 2015

Pr_20_31_53_13 Cementitious groutsPrimary


G10/443 Proprietary filling/ bedding of column bases

G10/55 Mortar filling/ Bedding of column bases

Specification data - Cementitious grouts

Product Reference

Conbextra UW

Standard product features

Technical properties:

  • Bond strength by pull off (to BS EN 1542): 2.2 MPa.
  • Chloride ion content (to BS EN 1015-17): 0.03%.
  • Compressive strength (to BS EN 12190): 25 MPa (1 day), 50 MPa (7 days), 70 MPa (28 days).
  • Reaction to fire (to BS EN 13501-1): Class A1.
  • Setting time: Six hours.
  • Time for expansion: 15 minutes (start), 2 hours (finish).


Technical data sheet catalogue

Technical data sheet catalogue

Fosroc Grouting Solutions

Fosroc Grouting Solutions

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