Crack width is a design figure
The engineer picks a design crack width for each surface: 0.2, 0.3 or 0.4 mm. It is not a trigger for repair, and some real cracks may be wider.
AS 3600 cl 2.3.3, 9.5.1● System 12 of 12 · Concrete repair
Concrete Crack Repair & Crack Injection
Stop the live leak, inject polyurethane where the crack is wet or moving and epoxy where it is dry and structural, then rebuild spalls and edges with repair mortar.
AS 3735 tanksAS 3600 crack control
11products
1CAD details
Up to 25 yrwarranty, depending on the systemwarranty, by system
● The build-up
Nine products, in the order of the job.
Each layer with the one figure that matters, from its data sheet. Tap a layer to see why it is there.
01
Stops the live leakACTFLEX HYDROPLUGSets in 2 to 4 minutes
Rapid-setting plug pressed into a chase cut square, at least 20 x 20 mm, never a V. Final set is within 10 minutes. A 5 kg pail does about 6 m of chase.
02
Injection for wet cracksACTFLEX PU200Foams to 8 to 20 times its volume
Hydrophobic polyurethane that reacts with the water in the crack. Inject through 10 mm packers at no more than 200 mm apart, drilled at 45° to meet the crack 60 to 100 mm deep. The seal is stable at 24 hours.
03
Injection for moving cracksACTFLEX PU50010 mm packers at 200 mm maximum
Hydrophilic polyurethane for cracks subject to movement and vibration. Same packer set-out as PU200: drilled at 45° to meet the crack 60 to 100 mm deep.
04
Epoxy for fine cracksCRACKLOCK E400LCracks from 0.05 to 3 mm
Low-viscosity structural epoxy that wicks into hairline cracks. The crack must be completely dry. Ports at about 450 mm. 400 mL cartridge.
05
Epoxy for wider cracksACTFLEX CRACK PRO 1200PSCracks from 3 to 8 mm
Structural epoxy for dry cracks, by pressure injection or gravity feed, to a depth of at least 12 mm. 600 mL cartridge.
06
Epoxy pastePROBOND 1100Fills 3 to 20 mm
Structural epoxy paste for filling, bonding and sealing over cracks. Working time is 40 to 45 minutes.
07
Repair mortarFORBUILD 1003 to 100 mm thick
Fibre-reinforced mortar mixed with water only. Up to 100 mm on horizontal work and 3 to 40 mm a pass on vertical. Keep 10 mm of cover over the steel.
08
Repair mortar, vertical and overheadFORCRETE 1003 to 100 mm per pass
Polymer-modified, fibre-reinforced mortar that rebuilds spalled concrete without formwork. Pot life is 30 to 40 minutes.
09
Epoxy repair mortarACTFLEX HBR25 mm maximum per pass
Two-part epoxy mortar for spalls, edges and stairs. It accepts a damp substrate. Apply between 15 and 35°C.
● The rules, in plain English
What the standards do and do not say.
The concrete standards set how much a structure may crack and leak. They do not set a repair method: that is the engineer's call and the maker's data sheet.
Tanks: fix from the wet side
On a liquid-retaining structure, leaking cracks and joints are treated from the liquid face wherever practicable. A lining must flex with the crack and not react with what is stored.
AS 3735 cl 7.3Then test again
A tank that fails its water test is repaired, refilled and given another full 7-day test.
AS 3735 cl 7.3A plain-English summary, not the standard. Check the current AS 3600 and AS 3735 for your job, or send us the job.A summary, not the standard. Check the current documents for your job.
● Every product in this system
Concrete repair: 11 products.
TDS and SDS open straight from the card.
● How it's done
Watch a leaking crack injected.
INJEXA SWM 1500: how to inject a leaking crack
- Find it
- Mark
- Packers
- Set up
- Couple
● 3D models
See every layer before site starts.
Each FORSPEC detail is modelled in 3D so the site team sees the build-up for concrete repair & crack injection before anyone opens a pail. Send the job and we model yours.
● On site
Real jobs. Real FORSPEC.
● CAD library
Drawn details, ready for your set.
1 standard detail for concrete repair & crack injection. Open one to view it and download the PDF and DXF.
● Typical values
Concrete repair mortars and resins: the numbers.
Typical values from FORSPEC research and development testing, each with the test standard used. Where a test report is named, the value comes from that report.
CRACKLOCK E400L
Typical values, R&D
| Property | Typical value | Test standard |
|---|---|---|
| Tensile strength | 34.6 MPa | ASTM D638-14 |
| Compressive strength | 80.5 MPa | ASTM D695-15 |
| Flexural strength | 70.3 MPa | ASTM D790-17 |
ACTFLEX CRACK PRO 1200PS
Typical values, R&D
| Property | Typical value | Test standard |
|---|---|---|
| Tensile strength | 29.03 MPa | ASTM D638-14 |
| Compressive strength | 55.22 MPa | ASTM D695-15 |
| Flexural strength | 35.38 MPa | ASTM D790-17 |
PROBOND 1100
Typical values, R&D
| Property | Typical value | Test standard |
|---|---|---|
| Tensile strength | 29.02 MPa | ASTM D638-14 |
| Compressive strength | 55.2 MPa | ASTM D695-15 |
| Flexural strength | 35.37 MPa | ASTM D790-17 |
FORBUILD 100
Typical values, R&D
| Property | Typical value | Test standard |
|---|---|---|
| Compressive strength, 28 days | 56 MPa | EN 12190 |
| Flexural strength, 28 days | 10.3 MPa | EN 1015-11 |
| Adhesion to concrete | 2.34 MPa | EN 1542 |
| Modulus of elasticity | 30 GPa | EN 13412 |
FORCRETE 100
Typical values, R&D
| Property | Typical value | Test standard |
|---|---|---|
| Compressive strength, 28 days | About 70 MPa | EN 12190 |
| Flexural strength, 28 days | About 10 MPa | EN 1015-11 |
| Bond to concrete | Over 2.0 MPa | EN 1542 |
| Modulus of elasticity | About 26 GPa | EN 13412 |
| Freeze-thaw | Pass, 300 cycles | ASTM C666 |
Typical values are a guide to performance, not specification limits. Check the current data sheet for the product before you specify.Typical values, not specification limits. Check the current data sheet.
● Questions we get
Straight answers, from the TDS.
How do you fix a leaking crack in concrete?
Stop running water first with ACTFLEX HYDROPLUG, which sets in 2 to 4 minutes. Then inject ACTFLEX PU200 through packers drilled at 45° to meet the crack. It foams on contact with the water and seals the crack from inside.
Polyurethane or epoxy injection: which one?
Polyurethane where the crack is wet: ACTFLEX PU200 for static cracks and PU500 for cracks that move. Both react with water. Epoxy where the crack is dry and the concrete has to be structural again: the FORSPEC injection epoxies need a completely dry crack.
What crack width can be injected with epoxy?
CRACKLOCK E400L suits cracks from 0.05 to 3 mm. ACTFLEX CRACK PRO 1200PS suits cracks from 3 to 8 mm.
How far apart do injection packers go?
For ACTFLEX PU200 and PU500, 10 mm packers at no more than 200 mm apart, drilled at 45° so they meet the crack 60 to 100 mm deep. For CRACKLOCK E400L epoxy, ports at about 450 mm.
How thick can concrete repair mortar be applied?
FORBUILD 100 goes from 3 to 100 mm on horizontal work and 3 to 40 mm a pass on vertical. FORCRETE 100 goes from 3 to 100 mm a pass. ACTFLEX HBR epoxy mortar goes to 25 mm a pass.
How fast does HYDROPLUG set?
It hand-sets in 2 to 4 minutes and reaches final set within 10 minutes. Cut the chase square, at least 20 x 20 mm, never as a V.
● Go deeper
Drawings, data sheets, jobs and news.
● The other systems
Twelve systems. One warranty.
● Not sure it suits the job?
Send us the job. We spec it.
Drawings, photos or a description. A FORSPEC rep comes back with the system, the spec clause, CAD details and a 3D visual within 6 business hours.