Jacketing

Definition

Jacketing is a strengthening technique used to enhance the structural capacity of existing foundations and superstructures by adding an external layer of material, such as concrete or steel, around the original structure. This method effectively increases the strength, stiffness, and ductility of a building or component, making it more resistant to forces like those experienced during earthquakes. It is often applied to retrofit and upgrade various structural systems to improve their performance under seismic loading.

5 Must Know Facts For Your Next Test

1. Jacketing can be applied to various structural elements, including columns, beams, and walls, significantly improving their ability to withstand lateral forces.
2. The choice of jacketing material is crucial; common options include fiber-reinforced polymers (FRP), reinforced concrete, and steel plates.
3. The application of jacketing requires careful assessment of the existing structure to ensure compatibility with the new materials and to prevent potential issues such as increased weight or stress concentrations.
4. Jacketing not only enhances strength but also helps in repairing damaged structures by providing additional support and improving their overall integrity.
5. This technique is particularly beneficial in areas prone to seismic activity, allowing older structures to meet current building codes and performance standards.

Review Questions

• How does jacketing improve the seismic performance of existing structures?
  • Jacketing improves the seismic performance of existing structures by increasing their strength, stiffness, and ductility through the addition of an external layer of material. This enhancement allows the structure to better resist lateral forces during an earthquake, minimizing damage and preventing collapse. The technique is especially beneficial for older buildings that may not meet current seismic design standards.
• Discuss the considerations that must be taken into account when selecting materials for jacketing existing structural systems.
  • When selecting materials for jacketing, it is essential to consider factors such as the existing structure's condition, compatibility with the new materials, weight implications, and potential stress concentrations. The selected material should enhance the overall performance without compromising structural integrity. Additionally, factors like cost-effectiveness, durability, and ease of installation play crucial roles in material selection for effective retrofitting.
• Evaluate the impact of jacketing on long-term structural resilience and its implications for urban planning in seismic zones.
  • Jacketing significantly enhances long-term structural resilience by enabling older buildings to withstand seismic events more effectively. This improvement can lead to reduced damage during earthquakes, ultimately saving lives and minimizing economic losses. In urban planning for seismic zones, incorporating jacketing as a standard practice for retrofitting existing buildings can contribute to safer communities and ensure that infrastructure can continue to function even after natural disasters occur.

Related terms

Retrofitting: The process of modifying existing structures to improve their performance, safety, and resilience against natural disasters or changes in usage.

Seismic Isolation: A design strategy that involves isolating a structure from ground motion during an earthquake, often using bearings or other devices to absorb and dissipate energy.

Reinforcement: The addition of materials, such as steel bars or fibers, to a structure to increase its load-carrying capacity and overall durability.