Concrete is the most common and one of the most important building materials. But often it might develop cracks which would not only make it weak in structure but would also disturb the aesthetics of the houses.
To avoid these later discrepancies observed in concrete, new varieties of concrete like pre-stressed concrete are now available in the market. Thanks to the significant technological advancements that have improved the qualities of concrete. But due to a high cost not many people invest in such improved quality of concrete for construction.
In this blog, we tell you about the reasons why the concrete develops cracks and how you could avoid it.
Reasons why concrete develops cracks?
There are various reasons and factors responsible for the concrete to develop cracks. Some of the most common reasons are:
1. Uneven Distribution of the Load
Concretes are designed to take a certain amount of load. Different construction materials like coarse aggregates, cement, sand, steel,etc., possess different ranges of elasticity in them. Totally apart shear stresses in these materials when they are combined to form a concrete results in cracks.
This could be avoided by using certified quality TMT steel bars in construction of pillars and slabs. This would prevent walls from developing cracks and will also increase the longevity of the structures.
2. Cracks due to Shrinkage
You might find the concrete cracking during the initial construction phases, this could be due to the excess evaporation of water contained in the concrete. This allows the top surface of the slab or column to dry more quickly than the bottom, as a result they pull each other apart.
Hydraulic shrinkage could be prevented by using a suitable quality cement, improving the compaction, and increasing the size of the aggregates. The early evaporation should be prevented until the end of setting.
3. Poor Workmanship
Not supervising the work on regular intervals during the process of construction could be one reason why the structures or concrete might develop cracks. This happens when negligence is caused by the workers with inferior ratio or improper mixing of construction materials, like sand, cement, and aggregates. This is a common cause of cracks being developed in walls, slabs, beams, etc.
This could be avoided by a proper supervision of work, and by avoiding carelessness done with mixing and other tasks during construction.
4. Thermal Shrinkage
Shrinking due to heat could be prevented by limiting the temperature increase in the concrete. For example, in case the construction and filling of concrete takes place during the summer seasons, cold water can be used for mixing and you could store the construction materials away from the sun in a dark and cold place.
How can concrete cracks be fixed?
Once a crack develops, it is important to seal it to prevent further deterioration. Ways that allow you to seal these cracks are:
1. Flexible Sealants:
best suited to seal cracks that are subjected to continuous ground movement. Using them allows the concrete to shift without affecting the repair.
2. Chisel & Hammer:
widen the crack to a minimum of one-quarter inch and break away any deteriorating concrete. The edges of the crack should be vertical or beveled in an inverted V. Then remove any loose material with a brush.
3. Repair Caulk & Other Sealant Options:
several repair caulks could come in handy while dealing with cracks which are less than one half inch wide. For ex: you can use concrete repair on horizontal or vertical surfaces and dry to firm, durable material.
There are many other ways through which cracks in the concrete could be fixed, like painting or polishing the surfaces can also help fill the cracks, and will allow walls to look fresh as ever.
It is common for the concrete to develop cracks in the early or the later stages of construction. This could happen due to a variety of reasons, ranging from the improper usage of the building materials to faulty construction procedures. It is important to discover these factors and to act on them to avoid the further damage to the structures and to also cut down on the money spent on future maintenance.