Choose your structural reinforcement interventions type to increase existing buildings safety level
Improving the structural safety of existing buildings is a multifactorial challenge. Understanding the causes of disruption and building’s weaknesses is certainly the first step in selecting the structural reinforcement interventions to adopt.
What are the guiding criteria that designers should follow in choosing a structural reinforcement intervention?
In this article, we’ll see how to browse among the various types of reinforcement interventions and how to obtain detailed analyses and calculations which comply with specified current standards requirements. With the support of a structural calculation software.
What is structural reinforcement
Structural reinforcement encompasses actions and intervention techniques aimed at improving existing buildings’ safety. Increasing structural safety can involve constructing individual structural elements (as in the case of local interventions or repairs) or the entire structure (as in the case of improvement or adaptation interventions), significantly impacting building’s overall behavior. Choosing the structural consolidation intervention to implement aims to counteract the development of local and/or fragile mechanisms improving structural behavior therefore increasing the security level for its users.
Structural Reinforcement for Masonry
The structural reinforcement interventions for masonry can vary based on the nature and extent of damages identified. As well as the specific characteristics of the masonry type and building. However, some of the most common interventions for masonry reinforcement include:
Resin or mortar injections
This technique involves injecting special resins or mortars into damaged masonry elements. Chose this intervention to reinforce existing masonry, restore cohesion and structural resistance. Especially in cases of original mortar pulverization.
Reinforced plastering is advantageous for heavily damaged and inconsistent masonry. The intervention involves creating two reinforced concrete slabs placed on either side of the masonry connecting them through transversal fasteners. This technique proves effective only if the reinforced plaster is applied on both sides of the masonry and suitable transversal connections, like injected bars, are firmly anchor to the reinforcement grids. Additionally, it’s essential to ensure adequate electro-welded mesh panels overlap, ensuring reinforcement continuity both vertically and horizontally.
Implementation of stitching interventions
Sewing operations, often made with steel bars or composite fibers, can connect separate parts of masonry, especially at corners or masonry intersections. Reinforced seams should be chosen in cases of significant discontinuity between structural elements.
Application of carbon fiber fabrics
Carbon fiber fabrics can be glued to masonry surfaces to enhance their resistance. This technique is often used in combination with adhesive resins.
Interventions for arches and corners reinforcement
Specific parts of masonry, such as corners and arches, may experience different stresses. Targeted interventions, such as the installation of tie rods or the use of composite materials, can be applied to reinforce these areas.
Specific restoration and reconstruction
In cases of severe or advanced damage (such as through-cracks, detachments, localized collapses, etc.), it may be necessary to proceed with the restoration or reconstruction of specific portions of the masonry or the replacement of damaged voussoirs (cut and uncut technique). This may involve the specific replacement of bricks and voussoirs with elements similar to the existing ones or the use of different materials from the original ones, aiming to make the intervention recognizable in case of conservative restoration.
Precompression chains and cables
To prevent masonry from overturning out of the plane, the insertion of steel chains is advisable. The use of chains should be part of an integrated approach to reinforcement, which could also include other interventions like resin injections, foundation reinforcement, reinforced plastering and other specific techniques according to the building’s needs.
Seismic reinforcement interventions
In seismic zones, reinforcement interventions may include the installation of anti-seismic devices, such as elastomeric isolators or dampers, to improve building’s capacity to withstand seismic forces.
Here’s a video that demonstrates how to calculate load-bearing masonry structures in seismic retrofitting.
Structural Consolidation of Reinforced Concrete
Structural amalgamation of reinforced concrete is essential to preserve and improve the safety and durability of structures exhibiting damage or deterioration. Interventions can vary depending on the specific nature of the issues encountered, but some common methods include:
Strengthening of reinforcements
This technique involves adding additional reinforcements to increase the structure’s strength. It may involve wrapping additional steel bars around existing structural elements or inserting additional bars into critical sections.
Epoxy resin injections
Epoxy resin injections can be used to fill any cracks present in concrete. This process enhances material cohesion and increases its strength.
Restoration interventions on concrete
Repairing degraded or damaged concrete surfaces can be done by removing the damaged concrete and applying new layers or restoration mortars.
Carbon fiber or composite reinforcements
Applying layers of carbon fiber or similar composite materials on concrete surfaces can improve the structure’s strength and load-bearing capacity.
Increasing cross-sectional area
In some cases, it’s possible to increase the cross-sectional area of structural elements like beams or columns to enhance load-bearing capacity. This can be achieved by adding new structural elements or implementing external reinforcements.
Anti-corrosion protection for reinforcements
Reinforcement corrosion is a common issue in reinforced concrete. Applying anti-corrosion coatings or using chemically modified concrete can prevent corrosion and preserve structural integrity.
Seismic reinforcement interventions
In seismic areas, interventions may include installing energy dissipation systems or seismic isolators to enhance the building’s resistance to seismic forces.
Structural monitoring technologies
Installing structural monitoring systems can be an integral part of reinforcement interventions. These systems allow continuous assessment of structural conditions over time, often using structural calculation software.
Advanced structural analysis
Utilizing advanced modeling and structural analysis can help identify critical areas and guide targeted reinforcement interventions. Using steel connection design software that employs the building’s 3D model can be the most suitable solution.
Carbon Fiber Reinforcement
Carbon fiber reinforcement is an advanced technique used in structural reinforcement to enhance the performance and strength of construction elements in concrete, stone, steel, etc. This method utilizes the exceptional mechanical characteristics of carbon fibers, which are lightweight, high-strength, and corrosion-resistant.
For further insights, refer to this technical article “Carbon Fibers in Construction“.