Crack Repairs

Unifor Construction Pte Ltd has successfully created a breakthrough in the field of crack repairs by inventing the UNIFOR CRACK INJECTOR. It is manufactured in Singapore and internationally-patented.

Unifor Crack Injection System utilises a low and constant pressure method to inject epoxy resin into fine cracks of all kinds of concrete structure.

The system maintains the pressure of the grouting material to at least
1.0 kgf/cm2, and limits its maximum to 3.0 kgf/cm2.

The clip-on injection nozzle allows for one-man operation in the grouting phase. The graduated cylinder of Unifor Crack Injector permits visual assessment of final grouting pressure.


1) Surface Preparation
Remove dust particles with a wire brush. Wipe up oil with thinner.

2) Sealing of Surface and Adhesion of Plug
Seal crack at lengths, stopping at intervals of 300mm for plug adhesion using UF Seal. (Interval length depends on crack width and depth). Push plugs onto crack until sealing material comes out of the 4 holes of the plug.

3) UF Seal Curing
Allow UF Seal to cure.

4) Installation of Unifor Crack Injector
Screw Unifor Injector onto plugs.

5) UF Grout Injection
Inject UF Grout into container using a grease/foot pump. Stop when pressure indicator rises to 3.0 kg/cm2. Proceed to next injector.

6) UF Grout Curing
Allow UF Grout to cure.

7) Finishing
Remove injector and grind off sealing material.




Unifor Crack Injection System uses both low and high viscosity epoxy resin for finer and larger cracks respectively.
Small final displacement indicator shows a minimum grouting pressure of 1.0 kg/cm2.

Unifor Crack Injector can deliver a maximum pressure of 3.0 kg/cm2. It has a capacity of 26.5cc when fully filled with epoxy resin.

Spring Extension
Pressure (kgf/cm2) Quantity (cc)
1 1.1 2.6
3 1.3 5.1
5 1.5 7.6
7 1.7 10.2
10 2.0 13.9
13 2.3 17.7
15 2.5 20.2
20 3.0 26.5








Structural/Non-structural crack repair in all concrete structures, such as:

  • Buildings
  • Bridges and tunnels
  • Roads and facilities
  • Water/Sewerage works and related facilities
  • Port/harbour facilities