7 Signs of Bad concrete pour and Effects

The signs of bad concrete pour can be observed in wet as well as wet conditions of concrete. In wet concrete, generally, two types of sign can be observed bleeding and segregation.

Concrete is a widely used construction material in the world. Concrete is used to construct structures to carry heavy load on it. It is used to construct structures like commercial as well as residential buildings, factories, culverts, bridges, dam etc.

Failure of a concrete structure may cause a huge loss of lives and properties. So, it is very important to design the concrete structure carefully and place the concrete without any foult in it.

In dry concrete, we can observe, cracking, scaling, spalling, etc. Here I have described all the signs of bad concrete pour in short.

A) Signs of Bad concrete pour in wet condition

1. Segregation:

When concrete is handled and placed in formwork, cement paste and aggregate are separated from each other, This process is known as segregation. Segregation also occurs when the concrete is over-compacted or vibrated in which cement paste comes to the top and aggregates settle at the bottom of the poured concrete.

7 Signs of Bad concrete pour and Effects - segregation and bleeding

Segregation in concrete affects the overall strength and durability of the concrete structure. So, concrete should be mixed thoroughly and placed in formwork avoiding too much height and vibrating in a suitable amount

2. Bleeding:

Bleeding occurs when the free water in the concrete mix is pushed upward to the surface due to the settlement of heavier solid particles such as cement and water.

There are some accepted limits but excessive bleeding in concrete can be harmful to concrete which reduces the strength of concrete. So, bleeding is a sign of bad concrete pouring.

The water-cement ratio is the main cause of bleeding in concrete.  As greater water-cement ratio leads to excessive bleeding. The type of cement used and the fineness of aggregate particles is used to determine the bleeding rate. Lesser fines in concrete the more bleeding will occur.

B) Signs of Bad concrete pour in dry condition

3. Cracking:

Cracking is the most common sign of bad concrete. Cracking may occur in beams, columns, and slabs as well. Cracking of concrete may cause also due to less curing and honeycombing.

7 Signs of Bad concrete pour and Effects - Cracks

4. Spalling:

When a significant portion of concrete splits off from the main member, it is called spalling.  Spalling may be caused due to not mixing of concrete uniformly. To avoid spalling,g concrete should be of uniform strength and uniformly placed in mold.

5. scaling:

Scaling mainly occurs in poorly finished or covered-worked concrete where too many fines and not enough entrained air is found near the surface.

6. Honeycombing:

Honeycombing in concrete generally occurs due to improper compactions or vibration of concrete during placing.

7 Signs of Bad concrete pour and Effects -  Honeycomb

The air void and gap left in the concrete where the mortar failed to completely fill the space between the coarse aggregate particles. It is the sign of bad concrete pouring if there is honeycombing seen after the removal of the framework.

7. Alkali aggregates Reaction:

Aggregates that are alkaline and chemically reactive may cause a chemical attack on concrete.  The reaction within concrete makes concrete weak from the inside. It is generally caused when we place the concrete mix on the clay or dust present in the mould and shuttering.

Besides these signs of the bad concrete pour, we have to keep in mind about the proper combination of steel and concrete. The proper amount of steel in concrete makes concrete durable and strong.

Delamination is generally started with the formation of steel and subsequent cracking of the concrete. It is very dangerous for the structure. To avoid delamination proper amount of steel and strength of concrete should be placed according to the design of the structure.

I hope this article remains helpful for you.

Civil Concept

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"Structural Engineer" with over 5 years of experience in estimation, structural design, and surveying. I am passionate about using my skills to create safe and sustainable structures. I am also a keen writer, and I enjoy sharing my knowledge and experiences with others.