What Is A Concrete Rehabilitation?
What Is A Concrete Rehabilitation?
Concrete Rehabilitation refers to the process of increasing the mechanical strength (such as tensile strength, compressive strength and flexural strength and shear strength) and durability of a concrete structure.
The effectiveness of rehabilitation can be evaluated by assessing the deformation capacity of various retrofitted components of the concrete structure.
To determine the appropriate rehabilitation method, it is necessary to consider the loadings that the structure will have to withstand in the future, as well as the expected service life of the structure. Additionally, the financial cost of the rehabilitation work must also be taken into account.
The ultimate goal of rehabilitation is to restore and increase the load-bearing capacity and durability of the structure.
There are several types of rehabilitation and restoration methods that can be used to repair and strengthen masonry and concrete structures. These include;
Masonry Replacement;
Using Similar Materials: This method involves replacing affected areas of the walls, where major deterioration has occurred, with materials that are similar to the original structure.
In cases where high-strength materials are required, special attention is given to areas such as corners where stress concentration can occur. The main objectives of this method include preserving the mechanical efficiency of the structure and improving the continuity of the masonry.
Using Buttress: This method involves constructing an external wall alongside the vulnerable structure. The buttress wall reduces the effects of horizontal forces and increases the structure’s strength against lateral deformations.
Crack Treatment:
Repointing: This method involves removing, cleaning, and filling the mortar joints with a new mortar that is compatible with the properties of the masonry units, resistant to deterioration and has similar mechanical properties and durability as the original mortar.
The main objectives of this method include increasing compressive and shear strength, improving the appearance of the structure, and reducing further deterioration.
Repointing by Steel Rod: This method involves placing steel rods over the cracks. However, using steel bars along the cracks decreases the surface area preparation and aesthetics. This method increases the tension and compression strength of the masonry.
Inserting and Covering Cracks: This method involves injecting mortar into the walls to reduce the cracks, thereby anchoring and bonding the wall elements, increasing the strength and inflexibility of the vertical masonry element by decreasing voids in the structure with cement mortar, liquid cement mortar or penetrating materials.
The effectiveness of this method is dependent on the mechanical properties of the newly injected material and the nature of the crack. The primary objective is to make the structure more homogenous and to resist earthquakes and lock cracks.
Pinning-repairing Cracks Using Steel Pins: This method involves inserting steel pins into holes drilled through the face of the masonry.
After inserting the steel pins, epoxy resin or cement grout is injected in order to provide bonding of reinforcing bars to the masonry elements and to establish the load transfer mechanism.
Pinning can be used to fix weak areas of masonry to the main structure, to stitch cracks, provide alternative routes for loads, and improve the overall stability of the structure.
Overall, the choice of rehabilitation method will depend on the specific needs and conditions of the structure. The main aim of rehabilitation is to restore and increase the load-bearing capacity and durability of the structure while also considering the cost and expected service life of the structure.
