Related Experiment Video
Updated: Jan 26, 2026
10:00
Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures
Published on: August 31, 2017
16.0K
A Seismic Strengthening Technique for Reinforced Concrete Columns Using Sprayed FRP
Kang Seok Lee1, Bang Yeon Lee2, Soo Yeon Seo3
1School of Architecture, Chonnam National University, Gwangju 61186, Korea. kslnist@jnu.ac.kr.
Polymers
|April 14, 2019
Summary
A new sprayed Fiber-Reinforced Polymer (FRP) system significantly enhances seismic resistance in concrete columns. This innovative technique improves shear strength and deformation capacity, offering a practical solution for retrofitting existing structures.
Area of Science:
- Civil Engineering
- Materials Science
- Structural Engineering
Background:
- Conventional seismic retrofitting methods for concrete columns often increase mass and require precise construction.
- Fiber-Reinforced Polymer (FRP) sheets offer a lightweight alternative but have drawbacks like surface treatment needs and joint issues.
Purpose of the Study:
- To investigate the structural and material properties of a novel sprayed FRP system for seismic strengthening of concrete columns.
- To evaluate the seismic resistance of concrete columns strengthened with this new sprayed FRP technique.
Main Methods:
- Developed a sprayed FRP system by mixing chopped glass/carbon fibers with epoxy/vinyl ester resin and applying it to concrete columns.
- Conducted cyclic loading tests on five shear column specimens strengthened with different sprayed FRP combinations and one control specimen.
Main Results:
- Sprayed FRP significantly improved shear strengths and deformation capacities of the concrete columns compared to the control specimen.
- The new technique demonstrated marked improvements in lateral load-carrying capacity and deformation.
Conclusions:
- The sprayed FRP system is a practical and effective method for seismic strengthening of existing concrete columns.
- This technique overcomes limitations of traditional methods and conventional FRP sheet applications.
Related Concept Videos
01:25Reinforcements in Concrete
458
Reinforced concrete is a composite material used extensively in construction, combining the compressive strength of concrete with the tensile strength of steel. This synergy is essential as concrete, while excellent at resisting compression, is weak under tension. Steel bars, or rebars, are embedded in the concrete to handle these tensile forces. The choice of steel is strategic; it shares a similar coefficient of thermal expansion with concrete, which ensures uniformity in response to...
458
01:22Fiber Reinforced Concrete
370
Fiber-reinforced concrete significantly enhances the structural and nonstructural properties of traditional concrete by incorporating fibers like steel, glass, and polymers. These fibers, varying from natural ones such as sisal and cellulose to manufactured ones like polypropylene and Kevlar, are mixed into hydraulic cement with aggregates. Steel fibers, often preferred for their robustness, contribute to improved ductility, toughness, and post-cracking performance. The concrete is classified...
370
01:22Design Example: Distributing Reinforcements in Concrete Sections
267
The topic explores the practical aspects of adjusting steel reinforcements within a concrete beam section to meet specific design requirements. When designing a reinforced concrete beam, it is essential to distribute the steel reinforcements properly to ensure structural integrity and efficiency. The example provided details a scenario where a beam requires a total steel cross-section of 4 square inches. The engineer identifies that the available steel bars have a nominal diameter of 1.693...
267
01:23Reinforcement
880
Positive and negative reinforcement are key concepts in operant conditioning, a learning process where the consequences of a behavior affect the likelihood of that behavior being repeated.
Positive reinforcement occurs when a behavior is followed by the presentation of a rewarding stimulus, increasing the frequency of that behavior. For example:
Positive reinforcement occurs when a behavior is followed by the presentation of a rewarding stimulus, increasing the frequency of that behavior. For example:
880
01:27Corrosion of Reinforcement
547
The corrosion of steel reinforcement within concrete is a process influenced by the material's inherent properties and external factors. The high pH level of around 13, provided by calcium hydroxide present in concrete, initially protects the steel reinforcement by promoting the formation of a passive iron oxide layer on its surface.
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
547
01:24Reinforcement Schedules
484
Positive reinforcement is a powerful method for teaching new behaviors to both animals and humans. B.F. Skinner demonstrated this with his experiments using rats in a Skinner box. When a rat pressed a lever, it received a food pellet. This immediate reward encouraged the rat to repeat the behavior. This method, where a reward follows every instance of the behavior, is known as continuous reinforcement. It is highly effective for establishing new behaviors quickly.
Once a behavior is learned,...
Once a behavior is learned,...
484