Repairing cracked or spalled concrete in buildings appears to be a no-brainer way to cut down on ownership costs. However, if the underlying damage is significant, it may be more cost-effective to knock everything down and rebuild in the long run.
Consider the long-term cost of ownership
The influence of the entire cost of running the building over its lifetime is an important factor to consider when considering whether to repair or replace damaged structural concrete. It may be less expensive to fix now, but investing more on a replacement for a long-term solution might save the structure a lot of money in the long run. Consider the long-term cost of ownership while weighing your options.
Galvanic pulse and ground-penetrating radar testing
Unseen circumstances and the level of damage must be identified as part of any lifetime cost study. Engineers frequently employ nondestructive testing to gather precise structural information. Sounding, galvanic pulse testing, ground-penetrating radar, and load tests are all part of this process.
Engineers can generate a more accurate prediction of remedial cost estimates with such facts on a building’s state accessible, making it significantly less likely that owners would suffer costly change order shocks when opting to perform repairs.
Structural lifespan review
In some circumstances, replacing older structures with a few years left before their pre-determined lifetime concludes may be the better alternative. Repair is usually the best option in other cases, especially if the damage does not impact the entire structure. In all cases, an engineer should conduct a structural lifespan review and condition study.
Determine the severity and origin of structural concrete damage.
Before settling on a repair method, determine the severity and origin of structural concrete damage. Some cracks may not require care, while others may have major ramifications. Again, get the help of a structural expert to examine any potential dangers to the structure.
Non-structural cracks over time becoming structural
Although non-structural cracks may not compromise the structural integrity of a structure, they may need to be repaired for aesthetic reasons or to avoid the cracks from worsening over time and eventually becoming structural. Other issues might arise as a result of minor fractures. Simply said, there are just too many technical and chemical variables at play for a do-it-yourself method to be effective.
Steps for Concrete Damage Repair in Reinforced Concrete Structures
If defective concrete has to be repaired, specific procedures must be taken to determine whether it needs to be repaired and, if so, to identify the appropriate restoration technique and material.
These procedures will ensure a successful repair process that is completed swiftly and effectively without wasting time or money. Concrete repair is required from time to time as the structure ages for a variety of reasons.
Investigating the cause of the concrete defect, assessing the extent and severity of the damage, evaluating the need for repair work, selecting appropriate repair techniques and materials, preparing the repair process, applying the repair technique, and finally curing the repaired area are all steps in the concrete repair process.
Determine the Sources of Concrete Flaws
In order to address the problem, it is necessary to accurately identify the reasons that lead to the fault. The restored structural part will be more durable and have a longer service life without the need for maintenance if the source of damage is eliminated or reduced to a large amount.
However, if the cause of concrete damage is not addressed, the same concrete fault may occur again in the future, resulting in a waste of money and labor.
It’s important to remember that the concrete problem in question might be caused by a combination of circumstances. In this scenario, all of the elements must be addressed, or the repair effort will fall short of its objectives.
Bad weather, cavitation, abrasion, reinforcement corrosion, chemical assaults, carbonation, fractures, design and construction errors, and aging of the structure are all factors that might compromise the structure’s durability and integrity.
If the damage is caused by a repeating occurrence, the structural repair must take into account the influence of the cause; however, if the damage is caused by a one-time event, this can be overlooked.
Determine the Amount of Concrete Damage
The extent of concrete damage is assessed to determine the severity of the damage and its impact on the structure’s life and serviceability. When the extent of concrete damage is established, it is possible to determine if the structural part needs to be replaced or repaired. It also aids in the implementation of preventative actions to prevent harm in the future for the known source of the damage.
The determination of how much concrete has deteriorated and how this deterioration impacts the structure’s service life, i.e. how much concrete has lost its strength or load-carrying ability, is part of the extent of concrete damage assessment.
Concrete soundness test
It is a common approach for determining the amount of concrete damage. When this procedure is paired with visual examination and performed by an expert engineer, it can offer a proper evaluation of the damage in many cases.
In this test, a hammer is struck on the concrete surface; a definite ringing sound indicates sound concrete, but a drummy, hollow, or dull sound indicates delaminated or disbonded concrete.
Deep delaminations or delaminations with just minor separation may not necessarily sound drummy or hollow, so keep that in mind. Placing a hand at the site of hammer blows or closely monitoring sand particles on the surface near the hammer blows might reveal the presence of such delaminations.
The concrete is delaminated if the hand feels vibrations in the concrete or if the sand particles appear to bounce somewhat owing to the hammer strokes.
While assessing the level of damage caused by hammer blows, the strength of concrete may also be assessed. The high strength of concrete produces a distinct ring when struck by a hammer, and the hammer rebounds intelligently. Concrete with little strength bounces with a faint thud and minimal hammer rebound.
Other Non-Destructive Concrete Testing can also be used to determine the level of concrete damage. More information about concrete NDT testing.
Assess the Need for Damaged Structural Concrete Repair
Repairing concrete structural elements took money and effort, and the damage had to be assessed to see if the structure needed to be repaired.
If the damaged concrete has an impact on the structure’s safety and serviceability, or if the damage is progressing quickly, the repair procedure should begin immediately.
However, if concrete damage is gradual and not severe (detected early on), a variety of options for slowing damage growth can be applied.
Even if repair is necessary, early discovery of damage would allow for a more efficient allocation of money to cover repair expenses.
Choose Concrete Repair Method
After obtaining sufficient information about the damaged region, its size, and severity, as well as the repair construction time frame, suitable, cost-effective, and successful selections of repair materials and methods may be made.
This data would also help establish when normal repair materials aren’t going to cut it and when nonstandard materials should be explored.
Repair materials and methods should be chosen in such a way that they do not hasten the deterioration of existing concrete or reinforcing steel.
Repair any concrete that has been damaged.
The preparation of the old concrete for the application of the repair material is critical to achieving long-term results. When applied to weakened or degraded old concrete, even the greatest restoration materials will work poorly.
The repair material must have the ability to adhere to sound concrete. Before applying fresh repair materials, it is critical to remove any unsound or degraded concrete.
Before applying concrete repair, saw cutting of the perimeter in a suitable shape, removal of loose concrete, steel cleaning and bonding agent coating on reinforcement steel, cleaning of the repair area, and application of the bonding agent on the concrete surface (to make a proper bond between existing and new concrete) should all be completed.
Use the Correct Repair Method
Depending on the degree of damage, a variety of typical concrete repair procedures and materials are available. Depending on the kind of concrete damage, the appropriate procedures and materials should be employed.
Cure Repaired Concrete
In order for concrete damage to achieve the requisite strength and durability, a suitable curing regime should be established for the repaired concrete area. Restore effort, expense, and time required to repair the defective zone are all wasted if the concrete is not properly cured.
Varying repair materials require different curing conditions; for example, some materials may require significant water curing while others may require less, and some materials may require proper protection with no water exposure until they reach the necessary strength.