S. V. Chandramouli, Manager (Technical); Sindhu S Saraswathi, Manager (Technical Services), M N Ramesh, Director, BBR (India) Pvt. Ltd., and N. Munirudrappa, Professor of Civil Engineering, Dayananda Sagar College of Engineering, Bangalore.
The increase in deterioration of bridge infrastructure is a large-scale national problem. Maintaining the existing bridge infrastructure network and adapting it to new capacity requirements has become one of the most challenging tasks for today's engineers. Bridges designed and built only a few years ago are now subjected to traffic loads well above the design ones. At the same time, it has become evident that the durability of bridges is not always guaranteed, even for relatively recent constructions. For bridges in urban areas, the space concerns are predominant and building a new bridge alongside an existing one is not a viable option. It is therefore necessary to intervene on the structure with most feasible, economical and efficient methods to upgrade, repair or strengthen the existing bridges while preserving, at least partially, its traffic bearing capacity. These challenges are greater than the ones required to design and build a new bridge. Fiber Reinforced Polymer (FRP) composites represent a new and promising solution to the shortcomings of several traditional materials and upgrading techniques and has a great potential to integrate into the bridge infrastructure. In the recent years several, researchers have investigated the performance of external bonded FRP composites and found to be a successful effective technique for upgrading structural element. This paper highlights the applications of external bonded FRP composites overlay for bridge infrastructure, the challenges involved and path to implementation.

Introduction and Background

The bridge infrastructure has been deteriorating for many years, a result of sometimes like harsh environmental conditions, heavy loads, insufficient maintenance, and, frequently, unintentionally damaging maintenance practices and it has be come a large-scale national problem. It has been widely reported that approximately 40% of India's bridges are either structurally deficient or functionally obsolete. Structural "deficiency" does not imply that a bridge is unsafe or likely to collapse. With proper weight restrictions and enforcement, most deficient bridges can continue serving traffic safely when limited to posted maximum loads. The main reasons for classifying a bridge as structurally deficient are low load ratings (or weight restrictions), deteriorated decks or deteriorated substructures. Maintaining the existing infrastructure network and adapting it to new capacity requirements has become one of the most challenging tasks for today's structural engineers. Bridges designed and built only a few tens of years ago are now have to carry traffic loads well above the design ones. At the same time, it has become evident that the durability of bridges is not always guaranteed, even for relatively recent constructions. In this context, the engineer is often asked to design refurbishments, enlargements and repairs on structures that are under heavy usage. This presents challenges that are even greater than the ones required to design and build a new bridge. For bridges in urban areas the space concern are predominant and building a new bridge alongside an existing one is not a viable option. It is therefore necessary to intervene on the structure while preserving, at least partially, its traffic bearing capacity. Due to budget constraints, many authorities are forced not to proceed with strengthening but to post load restrictions on their bridges as a temporary measure. A significant number of bridges all over the world need rehabilitation and strengthening.

The economic impact of bridge replacement is represented by not only the direct costs associated with demolition and construction of a new bridge, but also by the indirect costs associated with the loss of roadway use and traffic disruption. The latter are often difficult to quantify and foresee. In addition, high traffic volumes, tight construction budgets, and challenging roadway construction areas have put a strain on the ability of conventional materials to meet the public need for rapid construction, long-lasting structural components, lightweight and easy constructed facilities. This problem has created an urgent need for effective means of structural retrofit, repair and rehabilitation of bridge infrastructure as an alternative to bridge replacement. Casting additional elements, increasing cross-section size, and bonding steel plates are techniques that have been used in the past when widening or strengthening an existing bridge. These solutions can be expensive and difficult to implement, especially for working constraints (low-vertical clearance, head room,) scheduling constraints, economical constraints (minimum labor cost, minimum shut-down costs, material costs, etc) and long-term performance with strength and durability.

In the recent past, steel plate bonding was considered as an effective method for upgrading structural members. It began in South Africa and France, where steel plates bonded with epoxy resins were used for strengthening of concrete members [5]. This method originates from the strengthening of steel beams by means of adding steel plates. But, bridges that had been strengthened using steel plates were showing signs of corrosion after few years in service that resulted in the deterioration of the original structure. In Addition to the above, steel plate bonding included high installation costs, maximum labor, low on-site flexibility of use, aesthetically poor due to large changes in member size after repair, increased dead load and traffic interruption and this called for engineers to investigate for the alternatives. Considering all the above factors Fiber Reinforced Polymer (FRP) composites represent a new and promising solution to the shortcomings of several traditional materials and this shows a great potential for integration into the bridge infrastructure. In the past years, experiments have been conducted to investigate the applicability of FRP composite in bridge structures, including the applications of FRP composite to bridge deck, column and beam strengthening, etc. [1-4]. The performance of external bonded FRP composite have found to be a successful technique and an effective method for upgrading structural element. This paper highlights the applications of external bonded FRP composites overlay in bridge infrastructure, the challenges involved and path to implementation.
This is a premium article available exclusively for our subscribers.
If you are already a subscriber, please Login
If not, subscribe now and get access to well researched articles & reports on infrastructure construction, equipment & machinery, innovations & technology, project reports, case studies, and more. All this by simply paying just ₹200/- for a month of complete portal access, or a discounted rate of ₹1000/- for a full year of access.
JOGANI Reinforcement: Offering High Performance Engineering Fabric Products & Solutions
Jogani Impex is considered an industry leader in providing international grade Alkali Resistant ARACC Coated waterproofing mesh, which enhances the waterproofing systems and solutions in all types of buildings and structures, while saving money

Read more ...

Waterproofing Basements - Importance & Challenges
Assess Build Chem, a leading provider of construction chemicals, is ensuring long-term protection of buildings with its innovative waterproofing solutions that include a 5-step waterproofing method for deep and large basements. Sunny Surlaker, Head

Read more ...

Agrani: Setting Benchmarks for Quality & Reliability
By adhering to the highest industry standards, Agrani Group has gained a reputation for delivering solutions that surpass client expectations, avers Ramendra Bahadur Sinha, Managing Director. In the dynamic field of specialized construction that includes

Read more ...

FAIRMATE Introduces FAIRFLO CRYSTALLINE – a Crystalline Capillary Waterproofing Admixture for Concrete
FAIRMATE is catering to the Speciality Construction Chemical Industry by manufacturing a complete range of construction chemicals, along with cost-effective solutions and world-class services. The company has a long-standing expertise in the field

Read more ...

Nippon Paint expands into Rs. 12,500 cr Construction Chemicals market
In line with its global vision, Nippon Paint India is expanding its portfolio beyond the paint and coatings product range; it will now offer products and solutions under the broad categories: Dry mix, Repair and Maintenance, Construction Chemicals, and

Read more ...

Alkali-Aggregate Reaction in Concrete Structures and Preventive Measures
When the alkali of cement reacts with the reactive constituents of aggregates, the reaction is deleterious though very slow, and the distress is exhibited when the volume inside the concrete is increased due to the formation of alkali-silica gel, causing the

Read more ...

Optimizing Existing Structures Through Retrofitting
Despite understanding the potential of retrofitting and its distinct and far-reaching advantages in making existing buildings green and sustainable, retrofitting continues to be undertaken on a very limited scale; hence, it needs to be promoted and made mandatory

Read more ...

Cause of Distress of an Old Building Through Analytical and Micro-Analytical Methods
The technical service life of a reinforced concrete building is the time in service when structural safety is unacceptable due to either material degradation or exceeding the load carrying capacity, or both. In which case, the repair strategy may be adopted

Read more ...

Value Engineering with MCI®-2019 for Concrete Maintenance and Repair
True value engineering saves money without reducing service life or affecting the quality of construction or materials. Ideally, it adds value to the project. MCI®-2019 is one such value engineering solution that can extend the service life of existing

Read more ...

Agrani Milestone Use Carbon Fiber Laminates to Strengthen Slab
Ramendra Bahadur Sinha, Managing Director, Agrani Milestone, explains the remedial measures and challenges faced during slab strengthening of a deflected slab at IIT. NBCC India Limited undertook the strengthening of a deflected slab at a G+2 storey IIT building

Read more ...

Waterproofing Challenges & Remedial Measures in High Rise Buildings
High-rise buildings need special attention when it comes to waterproofing as the challenges inherent in them are peculiar in nature. Unfortunately, there is a lack of knowledge on the remedies and products available in the market as water- proofers continue to

Read more ...

Importance of Waterproofing Structures
The longevity of structures depends on how much resistance the building element will offer to water ingress. Water leakage not only reduces the durability but also hampers the serviceability or usability of the structure; hence, a good waterproofing system will

Read more ...

Terrace Waterproofing Solutions for Energy-Efficient Buildings
Terrace waterproofing is particularly important and is considered a priority as the roof is always exposed to harsh climatic conditions and weather changes. Rajeev Gupta, Business Head, ECMAS Construction Chemicals Pvt. Ltd. An effective waterproofing solution

Read more ...

Structural Rehabilitation of Reinforced Concrete Structures
Cement concrete is one of the most important construction materials and is practically basic to present-day developments. It is strong enough mechanically, yet vulnerable to deterioration. It thus gets damaged and even fails. This deterioration may be due to the weathering

Read more ...

Thermax - HDPE-SBS Waterproofing System for Basement Waterproofing
Gradual shift in lifestyle has driven the idea of modern construction towards developing underground spaces and buried structures to bring efficiency in use of space. However, the improved efficiency comes with an increase in challenges like infiltration

Read more ...

Waterproofing in Hilly Areas with Sub-Zero Temperatures
Industry experts Kunjan Popat, General Secretary, Waterproofing Association of India; Ramendra Bahadur Sinha, Managing Director, Agrani Enterprises, and MS Sudish, Director, SIWIN Institute of Waterproofing and Insulation, share the challenges

Read more ...

Dow Sealants for Sustainable Infrastructure
Durability is a key requirement for modern infrastructure projects – highways and roads, bridges, airports and airfields, walkways and plazas, parking structures and stadiums. Miles of concrete must

Read more ...

FAIRMATE FAIRCURE WC - White Pigmented Concrete Curing Aid
Buildings have major environmental impacts over their entire life cycle. Resources such as ground cover, forests, water, and energy are depleted to give way to buildings. Today, India has demonstrated

Read more ...

Repair and Rehabilitation of A Minor Bridge in Shravasti District  (UP), India
Scour is a natural phenomenon caused by the erosive action of flowing stream on alluvial beds. Failure of bridge due to scour at their foundations, which in this case consisted of abutments and pier, one 1.2 dia

Read more ...

Faircoat Anti-Carbonation Coating Protects Concrete Structures Like Flyovers, Bridges & Buildings
To protect concrete structures like Flyovers, Bridges, Parking areas, Big Commercial and Residential Buildings, the normal decorative exterior paint will not serve the purpose as these paints are not vapour permeable

Read more ...