Without them, our travel network would collapse and leave many fine towns and cities isolated from the rest of the country and the world, hence the need for proven solutions to the issue of bridge repair and maintenance.
Bridge Structural Repair in the UK
There are nearly 100,000 bridges in the UK, the majority of which are small, local authority-owned structures (81,000), the rest comprising highways (8,500) and rail bridges (7,000). Three quarters of all highways bridges consist of reinforced concrete, and whilst concrete accounts for the make-up of the majority of rail bridges, these structures are also made of other materials such as cast and wrought iron.
Long-Term Exposure on Concrete Bridges
Whatever a bridge’s properties, long-term exposure to the elements and traffic-based wear and tear will potentially lead to a number of issues, including:
- Water Ingress: resulting in reinforcement corrosion, surface cracks or spalling
- Dynamic and Static Load: where a structure’s capacity is overloaded due to extra traffic, etc
- Wide Temperature Variation: thermal stresses caused by temperature extremes
- Carbon Dioxide: results in carbonation which attacks steel reinforcement
- Chlorides Ingress: caused by penetrative salt in water or de-icing procedures
- Freeze/Thaw Action: creates stresses in the concrete matrix
- Surface Erosion/Abrasion: triggered by concrete elements submerged in water
- Fire Damage: resulting from traffic accidents and leading to structural integrity
Testing is a vital part of bridge repair and protection specification. It can be carried out using various techniques including a basic visual survey, hammer testing, chloride analysis techniques, carbonation testing, concrete-to-reinforcement cover surveys and half-cell potential testing. These assessments will help play a part in Sika’s preparation of any project-specific specification offering.
Safeguarding Function & Investment
The consequences of not addressing bridge repair problems will be costly and possibly even dangerous in the long-run. Therefore, evaluating the causes of the deterioration is just as important and vital to evaluating and offering the correct repair strategy.
Appropriate lifecycle costing and assessment in all areas of bridge design, construction and management safeguards the owner’s investment and helps maintain the structure’s capabilities and community functions. Additionally, landmark structures can become an integral part of a city, region or national heritage.
Lifecycle costing and management offers bridge owners the best approach to minimising any closure times whilst increasing required periods between scheduled maintenance works. This helps incur a minimal expenditure over the structure’s full service life. Sika provides bridge owners and their maintenance managers with the right design and planning tools, followed by well-designed and proven refurbishment solutions and systems to considerably increase the time between necessary maintenance and repair cycles.
Concrete Bridge Repair Strategy
It’s essential to consider specific refurbishment requirements of each bridge project, as diagnosis is likely to differ on a case-to-case basis. These requirements can have a major influence in deciding correct design, planning and construction procedures as well as future maintenance works.
Examples of project-related requirements include;
- Durability: products used in bridge remedial works must provide adequate durability
- Duration of Closure: maintenance work has to limit traffic disruption to a minimum
- Aesthetics: aesthetic considerations can play a vital role in structural remedial works
- System Compatibility: a full-range system supplier helps with complex bridge repair
- Total Life Cycle Costing: costs influence the appropriate repair concept and materials
- Exposures/Site Conditions: site access and space can also effect materials and repair method
- Trafficking: special materials are required for repairs during live traffic loading
- Ecology: use of sustainable materials is playing an increasing part in bridge refurbishment
Sika Solutions for Structural Strengthening & Protection of bridges
As the worldwide leader in the structural-strengthening of all types of reinforced concrete structures, Sika provides a full range of fully-tested and approved strengthening systems.
Sika Flexural Strengthening Solutions
- Sika® CarboDur® – carbon fibre-reinforced, polymer-based plate system
- Sika® CarboStress® – post-tensioning system for structural strengthening
- Sika® UHM Plates – bespoke ultra-high modulus plates for cast-iron or steel beams
Sika Solutions for Shear Strengthening:
Sika Solutions for Repairs
- SikaTop® Armatec®110 Epocem; Sika® MonoTop® 610 – reinforcement corrosion protective coating & bonding primer.
- Sika®MonoTop®-612 & 615 – repair mortars for patch repairs
- Sika®Armorcrete – pourable micro concrete
Sikaset® – fast-setting repair mortars
- SikaCem ® 133 – high performance dry spray applied repair mortar
Like roads, rails, water and gas utilities, bridges are a vital part of the world’s infrastructure. When it comes to the upkeep and repair of these fine, upstanding structures, no bridge is too far for Sika.