Concrete Deterioration: Preventive Measures and Causes
The problem of concrete degradation is a major concern for many establishments, including commercial, residential, and municipal buildings. Before you can come up with a plan for repairing and reinforcing a concrete structure that is failing, you have to know why it is failing in the first place.
A variety of factors can cause concrete to deteriorate. Even though it is an extremely stable and robust material, it won't last forever without proper installation and maintenance.
Here are some practical tips that you should keep in mind if you wish to ensure the strength and integrity of your constructions.
Common factors of Concrete Deterioration
In addition to problems with placement and service conditions, deterioration rates in concrete are affected by many factors, those are as mentioned below:-
Issues related to placement
A number of factors contribute to the proper placement of concrete. This ensures that the structure is designed in accordance with the specifications, permits the correct use of the structure by the end user, and prevents the building from degrading too soon after its construction.
Cracks in concrete are one of the most obvious signs of placement problems. The problem can arise due to a number of factors, such as a weak substrate, a high volume of water-to-cement ratio, ineffective curing techniques, an incorrectly timed installation of the control joints, and other installation issues.
Additionally, it can be a sign of a more serious flaw in the design of the structure, such as improper spacing between control joints or a lack of reinforcement.
Problems with concrete placement can be seen in the following ways:-
1. Bug holes or tiny air bubbles on the concrete's surface.
2. Rock crevasses in the cement aggregates.
3. Hives-like Cold joints.
Problems with service condition
A service condition problem occurs when a structure is acquired or used in a way that caused a problem with its installation or mixture. The following are some common signs of a service condition issue:-
1. Metals inside the concrete are corroding (reinforcing steel).
2. During freeze-thaw cycles, water-soaked concrete expands, scales, and delaminates.
3. Degradation is caused by the harsh chemicals used to treat ice and snow. In regions where the acid rain is extremely bad, this can also happen.
4. Aggregate-alkali reaction.
5. Since erosion constantly happens to some extent in nature, it is the most challenging concrete degradation issue to fix.
Concrete degradation causes
Inadequate maintenance, environmental factors, inferior materials, and poor workmanship can all cause concrete to degrade:-
Factors related to environmental
Concrete degradation is mostly caused by environmental conditions. Concrete rapidly absorbs moisture, which can be problematic in areas that see frequent freeze-thaw cycles.
In cement paste or non-durable aggregates, freezing water creates expansive pressure. Another element of the atmosphere, carbon dioxide, can damage concrete by interacting with the cement paste on the surface.
Materials and workmanship
Early concrete buildings were constructed using materials and techniques that might provide issues. For instance, early concrete's usage of aggregates like broken brick and coal cinders led to porous, weak concrete that absorbed water.
Concrete can fracture and develop white surface stains as a result of alkali-aggregate interactions inside the concrete. When grading aggregates by size, it was not always done correctly to guarantee an equal distribution of tiny to big parts.
Structural Design Defects
Historic concrete constructions that have structural design flaws may deteriorate for a variety of reasons. For instance, there was frequently inadequate protective concrete covering surrounding reinforcing bars.
The lack of standards for expansion-contraction joints to reduce pressures brought on by thermal movements, which may result in cracking, is another design issue with early concrete structures.
Improper Maintenance
Concrete can deteriorate over time as a result of improper preservation of old structures. The main cause of the deterioration of old concrete is water, and extended exposure to it may be quite harmful.
Potential sources of construction issues include unregulated absorption of water from the moist ground and unrepaired roof and plumbing leaks through the outer cladding.
Delaying the repair of gaps that allow water infiltration and freeze-thaw assaults might potentially result in the collapse of a structure.
Tips to prevent the Concrete Deterioration
Reinforcement of concrete
In concrete applications, steel reinforcement is frequently utilized to strengthen, stabilize, and improve the soundness of the final construction.
But steel may be vulnerable to rust, particularly in cold and wintry settings. Repairing a single isolated region probably won't stop rust from spreading because it's very hard to do so.
Tests for sulfate
Your concrete is more prone to cracking when exposed to water that has a lot of dissolved sulfates. Sulfate-containing water entering the concrete, crystallizing and expanding causes a sulfate attack.
To learn more, watch the following video tutorial.
Video Source: civilogy
The cement paste could also disintegrate, weaken, and eventually erode as a result of the sulfate salts.
Proper proportion of cement-aggregates
Under specific circumstances, an alkali-silica interaction will produce an expanding gel that will induce cracks in concrete. This reaction can be identified by "map cracking" and white or gray deposits that resemble gel.
Test the cement-aggregate mixture for the limit of cement alkalinity, expansion, and petrographic, or rock and mineral, features to reduce this reaction. Reduce the alkali content of the concrete by mixing in the slag or low-alkali fly ash with the cement.
