• Understanding the Types of Cracks in Concrete: A Comprehensive Guide

    June 4, 2024 | By Kenza TMT Steel Bars

    Concrete is a material that you use abundantly in construction. You can use them in foundation, walls and other parts of your building. Even so, it is not indestructible and you may see cracks or damages on it over time. Read on if you are wondering how many types of cracks can occur in a building

    Types of Cracks in Concrete: Difference Between Structural and Non-Structural Cracks

    It is natural to worry if you see  different types of cracks in concrete of your building. But you can rest assured because a lot of cracks are harmless. They might be just purely cosmetic. Whether it is harmful or not, you can divide concrete cracks into two types: structural and non-structural.

    Structural Cracks

    These cracks suggest that the integrity and stability of your structure has been compromised. You will no longer be able to guarantee that the building has a sound load bearing capacity because these cracks can lead to severe damage to your structure. You might see comparatively wider cracks. There is a chance that you might also see other signs of structural distress, such as sagging beams or columns.

    Non-Structural Cracks

    They are usually narrower and probably cosmetic. Non-structural damages are usually caused by factors like temperature changes, drying shrinkage, or minor settlement and can lead to  problems  like water leakage and reduced aesthetic appeal.

    Types of Structural Cracks in Concrete

    These are the cracks that can lead to severe damages if not dealt with properly 

    1. Flexural Cracking

    These cracks happen if there is a problem with the reinforcement of your building or if the load on it is beyond the load it can bear. In such instances, there is a blending or flexing in the concrete of your structure which leads to the formation of vertical cracks in areas where the bedding forces are applied -the  beams, slabs, or walls.

    2. Shear Cracking

    These also indicate that your building is bearing excessive load, much more than it was designed to handle. These cracks are diagonal and you usually see them  near supports or around openings. 

    3.Internal Microcracking

    You cannot see these cracks with plain eyes as they are tiny and occur within the concrete. It can eventually cause larger cracks over time with high stress 

    Types of Non-Structural Cracks in Concrete

    There are a number of non-structural cracks you need to know about.

    1. Plastic Shrinkage Cracks

    They are usually shallow and do not really affect the structural integrity of your concrete. After the concrete is poured on its plastic (wet) state and left to dry, there is a chance that small cracks occur on the surface as the water evaporates and the concrete shrinks. 

    2. Plastic Settlement Cracks

    When you pour concrete, there is a downward movement of concrete mass before it fully sets. Sometimes it settles unevenly – maybe due to improper compaction, incorrect concrete mixing, varying subsoil conditions, or uneven moisture distribution. They can cause cracks in the surface of your concrete.

    3. Cracks Due to Formwork Movement

    Formworks are the molds you can use to shape the concrete. If it moves during the setting process, the movement can cause cracks in the concrete. These cracks are usually seen around the edges and corners of the molds.

    1. Crazing

    Crazing does not affect the structural integrity of your concrete. But it is aesthetically not pleasing and difficult to clean. They are thin and shallow cracks you see on the surface of your concrete. Crazing usually happens when there is a rapid drying or improper curing of the concrete.

    2.Drying Shrinkage Cracks

    During the curing process, your concrete tends to lose moisture and shrinks, reducing volume over time. This causes it to create narrow, deep and random cracks. Because it is deep, drying shrinkage cracks can impact the durability of your structure.

    3. Cracks Due to Thermal Movement

    Concrete can expand and contract as temperature around it changes. When the temperature changes are quite significant, it can cause restraints on the concrete, resulting in cracks. They are comparatively deep and can affect the integrity of your building.

    Other Types of Cracks in Concrete

    There are some other types of concrete that you may see if you are dealing with concrete

    1. Corrosion Cracks:

    If your concrete contains steel reinforcements and it rusts, it  expands and causes your concrete to crack. Making use of the best TMT Steel bars can help reduce such cracks.

    2. Chemical Reaction Cracks:

    Sometimes, concrete reacts with chemicals in it which causes it to expand and crack.

    3. Foundation Cracks:

    Sometimes, cracks appear on your building’s foundation. They can be structural or non-structural and may be caused due to factors like soil movement, settlement, or temperature changes in your environment. The cracks can be minor cosmetic ones or serious structural problems.

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