Tempo-PCE has successfully used grout injection for structural/ strengthening repairs on a large number of projects, including culverts, bridges and tunnels.
The low-pressure injection with a latex-cement blend can link delaminated brick rings, increase brick strength, and thicken arch barrels by penetrating the backfill.
The key advantage of grout injection for strengthening is the retaining of the structure’s inherent flexibility: the strength of the injected material is 23N/mm2, which is comparative to existing mortar, avoiding overstiffening of the structure. Alternatively, where lower strength lime has washed out, weakening a structure, this can be replaced by the higher strength material blend.
Low-pressure injection avoids movement to the brickwork or backfill. It also assists absorption, as the injected material can easily replace water or air in the structure. The grout replaces missing mortar, penetrates cracks, and fills any voids. Its inherent fluidity enables penetration into the masonry through a 10mm probe hole.
The low-pressure approach allows work from underneath the soffit, with the road/rail structure remaining in full use – offering a low impact alternative to conventional methods of repair, and in most cases making traffic management unnecessary.
- Link masonry and brick rings
- Fills large voids
- Can link to concrete saddle
- Reinforces backfill to thicken arch barrel
- Use of low pressure allows saturation of a structure
- Resistant to road salts
- Retains appearance of existing structure
- All quantities can be measured and recorded
- All work from below or above
- All equipment can fit through a manhole
Health & Safety / Environmental
- No special PPE Required
- No specific storage or containment required
Application Conditions & Limitations
- Any structure that has flowing water will require some injection of waterproofing grout before the cementitious (strengthening) grout is applied. The waterproofing grout must only be applied in carefully selected locations and in controlled amounts, so as not to use up spaces that will need to be injected with the strengthening material. On a typical masonry structure, localised injection of the waterproofing grout into the backfill would give temporary relief from the flowing water to enable the cementitious injection to be effective.
- If substantial brick repairs are required, these should be carried out before grouting works commence to allow the new brickwork sections to be fully bonded with the existing structure.
- Where there is a lot of missing pointing, this should be replaced as the grout is generally fine enough to run out through the missing pointing areas and will result in product loss.
Previous Site Environments
- Confined space
- Over a water course with EA approval
- Tunnel under a working road
- Different types of road bridges from below
- Unrestricted traffic or minimal use of traffic management
- Can be used in conjunction with a low-pressure waterproof system – see Masonry Waterproofing.
- Can give additional penetration into a masonry structure with the use of low-voltage electricity – see Masonry Electro Grouting.
- Summersbury Road Bridge, Surrey Council
- Waveley Road bridge, Barnet Council
- Hale Lane bridge, Barnet Council
- Kingsway service pipe tunnel, LB Camden Council
- Northumberland Ave Service Pipe Tunnel, FM Conway
- Strand service pipe tunnel, LB Westminster Council, FM Conway
- Baynards Rd Bridge, Surrey County Council
- Ickleton Rd Bridge, Cambridge County Council
- Cotterstock Rd Bridge, Northamptonshire County Council, Kier Group
- Byegrove Rd Bridge, LB Merton Council