Hello friends, in this arrival I am going to explain to you about the ” Requirement of good, durable and strong Concrete structure”. In a later post, I will also show you how to test the durability of the concrete structure. So, please read carefully one by one to get full knowledge.
The more the structure durable, the more it will be long-lasting. So, Everybody loves their property and want to stay as long as possible. In case of building it must be safe as well as economical considering the durability of the building.
The properties of concrete depend upon the proportions and type of its ingredients. A properly designed concrete mix is very durable.
How to improve the durability of concrete structure?
The concrete should be mixed thoroughly to form a homogeneous mixture. If it is not mixed thoroughly then all the ingredients of the mixture like cement, sand, and aggregate could not touch each other and can not get the required strength.
It can be done with the help of a mixture of about 15 to 25 rotation of mixture with the limiting capacity of mixture pots. If concrete is mixing with hand manually then it should be mixed by stirring all gradient up and down for more than 10 times.
Compacting of concrete is very necessary to prevent it from segregation. Segragation is process of separating the ingredient of concrete from each other.
It should be keep in mind that concrete should be compacted with the help of compacting machine or vibrater layer by layer according to design.
Over compaction of concrete may cause the ingredient like aggregate to settle down living the sand and cement at the upper portion of the structure. This makes concrete weak in different regions.
So, Concrete should be compacted properly to prevent it from being porous and weak.
The most important factor for concrete to be durable is the proper curing of the concrete structure. The process of spreading water on the structure after a few hours and during the hydration period is known as curing.
During the hydration period concrete gets its strength. Without curing, there is no chance that a concrete will gets its full strength.
According to cement curing has a different time period. OPC needs at least 7 days for curing whereas PPC needs about 10 days for curing.
It also depends on the hot weather. It the weather is hot, then curing time may increases than actual requirement of concrete for curing. So, Sufficient curing of concrete is required for developing its full strength.
Water Cement Ratio
The water-cement ratio is the ratio of water to be added in cement while preparing a concrete structure.
It should be maintained very wisely because more water cause bleeding in concrete and less water may cause segregation. And both of them reduces the strength of concrete.
So, The water-cement ratio should be appropriate, considering the strength and workability criteria.
The mix proportion is to provide the ingredient of concrete-like cement, sand, and aggregate in fixed proportion according to design criteria. Any of the disturbance of the proportion of ingredient may reduce the required durability of the concrete structure.
So, The concrete mix should be designed properly and should have all the ingredients in the right proportions.
Use of fresh water
The water used for mixing should be free from all harmful organic substances.
The presence of organic substances may react with concrete internally and damage the ingredient like steel, quality of cement, etc.
Size of aggregate
Aggregate contains more than 50% part of the concrete structure. It doesnt mean that for higher strength of concrete we should provide larger size of aggregate.
To get proper strength and better durability the aggregate should be hard, durable, and properly graded. For most R.C.C. works, 20 mm size of aggregate is suitable to make concrete.
Quality of Cement
The most important ingredient is cement. Cement is binding materials of structure so, No structure are possible to construct without cement.
The cement used for R.C.C. work should be of good quality and measured by weight only, and not by volume.
External Factors affecting durability of concrete
- Concrete Facing a very hot or cold climate may reduce the durability of concrete.
- Concrete facing several impacts or sudden load may affect the durability of the structure.
- Concrete facing continuous and periodic load like a bridge, a culvert may reduce durability.
- Structure near water resources may reduce their durability.
Internal factors affecting durability of concrete
- Quality of steel rod used in it.
- Quality of ingredient used in the concrete structure.
- The shape of concrete structure.
- Concrete cover provided in the concrete structure.
So, friends, I hope this article on “durability of concrete structure” remains helpful for you. Please share and comment if you have any questions.