Repairing Concrete Damage: Concrete is an extremely durable building material that has a long duration of service when correctly proportioned and put on the job site. Currently, there are many concrete structures have a working life of only 20-30 years and are in need of repair. Unfortunately, in such cases, the concrete homes requires maintenance or repair in order to remain functional.
Not only does the house age, but other factors may have a detrimental impact on the longevity and integrity of concrete houses. That is, the result of many factors as will be discussed below. In such instances, concrete repair becomes mandatory as soon as possible.
Certain measures must be taken to determine whether defective concrete requires to undergo repairing or not, and to specify the appropriate repair methodology and material when repair is necessary.
These measures will ensure that the repair process is completed successfully and efficiently, without wasting time or resources. Concrete repair is necessary every now and then as the structure ages for a variety of reasons.
6 Steps to Repairing Concrete Damage
1. Identify the reasons for damage
The first and most critical step in repairing damaged concrete is determining the source of the damage. Identifying the precise source of damage and minimizing or removing such sources can only assist to sustain the repair for a prolonged period of time. If we try to repair concreter without first determining and resolving the source of the damage, the repair can fail again due to the same reason, resulting in a waste of time and money.
To effectively address the problem, it is necessary to thoroughly investigate the causes of the defect. If the source of the damage is removed or significantly reduced, the repaired structural element is more stable and has a longer period of service life without requiring maintenance.
However, if the underlying cause of the concrete deterioration is not addressed, the same concrete defect could recur in the future, resulting in a waste of expenses and effort.
Concrete defect under investigation could be caused by more than one or multiple causes. In this scenario, all considerations must be considered, or the repair work would fall short of its objectives.
The following factors can have a detrimental impact on the reliability and integrity of concrete structures: cavitation, corrosion, chemical attacks, carbonation, abrasion, fractures, design and construction flaws, and structure ageing.
Whether the reason of the damage is repetitive, the structural repair must consider the impact of the cause; but, if the reason is a one-time occurrence, this may be overlooked.
2. Evaluate the Extent of Deterioration
The next stage in concrete rehabilitation is to determine the degree and how severe the damage is, which entails determining the amount of concrete has been affected and how this deterioration will impact the concrete’s potential service life. In other terms, determine the amount of strength or load carrying ability lost.
Assessing the degree of deterioration to concrete enables an understanding of the nature of the damage and its impact on the structure’s service life and functionality. Once the extent of concrete deterioration is determined, an informed decision can be taken about whether the structural member should be replaced or repaired. Additionally, it assists to perform preventative steps to avert any harm caused by the known reason of the deterioration.
Assessing the extent of concrete deterioration entails determining the amount of concrete that has been damaged and how this degradation affects the structure’s service life, i.e. amount of concrete has weakened its strength or load-bearing capability.
Numerous non-destructive tests are used to determine the extent of concrete damage. The following is a list of critical non-destructive measures that concrete experts use to determine the quality or harm to concrete.
- Concrete soundness test
- UPV Test
- Visual inspection
- Rebound Hammer Test
- Depth of Carbonation
- Amount of Chloride
3. Assess the Repair Requirements
Repairing concrete structural elements requires considerable expenses and time, and the extent of the damage must be determined in order to decide whether the structural element requires repair or not.
If the deteriorated concrete compromises the structure’s stability and serviceability, or if the damage progresses rapidly, the repair should begin immediately.
Not all concrete needs urgent repair. If the damage to the concrete compromises the homeowner’s protection or the house’s potential serviceability, immediate repair is needed.
It may be possible to slow the rate of degradation by performing some repair work as soon as concrete damage is detected. As a result, we can conclude that proper and routine house maintenance decreases the expenses of repair and, eventually, saves money.
If concrete damage occurs slowly and is not serious (detected early), a variety of alternatives may be used to retard damage progression.
Even if repair is necessary, early identification of damage allows for more organized making of budgets to cover repair costs.
4. Choose Appropriate Repair Technique
After obtaining sufficient information about the damaged area, its size and severity, and the duration of the repair construction, it is possible to make cost-effective and successful choices about repair materials and procedure of repair.
Additionally, this knowledge will indicate when standard repair materials are unlikely to work adequately and when nonstandard materials ought to be regarded.
The repair materials and procedure should be chosen in such a way as to avoid accelerating the deterioration of existing concrete or reinforcement steel.
5. Prepare Deteriorated Concrete for Repair
Preparing the old concrete for application of the repair material is critical to achieving long-lasting repairs. Even the best repair materials can work inadequately when added to weakened or degraded old concrete.
Generally, old or current concrete (damaged concrete) should be cut into an appropriate shape (square, rectangle, etc.) using a grinder or hammer and chisel tools. Refer to the following illustration.
To ensure that the repair is long-lasting and robust, the bond between the existing and new concrete should be strong. As a result, it is important to extract loose concrete to a depth sufficient to provide a good bonding surface for the existing concrete.
When loose concrete is removed, the reinforcement steel is exposed and requires special care. In general, if the RFT is exposed to more than 1/3 of the periphery, the concrete surrounding the steel should be completely removed.
When dealing with corroded steel, the bar should be exposed and cleaned until the steel is no longer corroded.
Clean the repair region after preparing the reinforcement steel. Using a wire brush or an air blower, clean all dust and loose particles from the repair region .
If all cleaning is complete, add another bonding agent to the old concrete’s surface to ensure a strong bonding with the new concrete. Apply the bonding agent a few hours prior to the beginning of the concrete pour. Prevent further damage to the region until the repair materials have been cast and cured.
6. Perform Appropriate Repair Technique and Cure Repaired Concrete
After completing the above steps for concrete repair, the repair materials and method of repair must be determined. Repair materials and methods should be chosen based on the extent of concrete damage, the scale of the repair work, and the anticipated completion period of the repair work, among other factors.
The repair materials and procedure should be chosen carefully to avoid accelerating the deterioration of existing concrete or reinforced steel.
An appropriate curing method should be selected for the repaired concrete region to ensure the necessary strength and durability of the concrete. If concrete is not properly cured, all repair efforts, costs, and time spent in repairing the defective zone are in vain.
Diverse repair materials require varying curing conditions; for example, some materials need huge amount water curing while others require less, and some materials need sufficient protection without exposure to water before they reach the required power.