What Is Hardened Concrete?
Hardened concrete is a type of concrete that is strong and have the capacity to bear the structural as well as service loads that are applied to it. Hardened concrete is one of the strongest and durable construction materials.
- What Is Concrete | 31 Different Types of Concrete
- What is Plum Concrete | Application of Plum Concrete | Mix Design of Plum Concrete | Methodology of Plum Concrete
- What Is Honeycomb In Concrete | Cause of Honeycomb In Concrete| Cure of Honeycomb In Concrete | Types of Grouting
- What Is Concrete Topping | Topping Slab Definition | Types of Topping Slab | Advantages & Disadvantage of Topping Slab
- RCC Full Form | What Is RCC | Advantages & Disadvantages of Reinforced Cement Concrete | Properties of RCC | What Does RCC Stands for
- What Is Shotcrete | Shotcrete & Concrete | Shotcrete Technology | Types of Shotcrete Technology | Advantages of Shotcrete | Disadvantages of Shotcrete
- What Is Concrete Screed | Concrete Screed Specifications | Characteristics of Concrete Screed | Advantages & Disadvantages of Concrete Screed
Properties of Hardened Concrete
There are various properties of hardened concrete which are as follows.
1. Strength of Harden Concrete
The strength of the concrete is defined as the maximum amount of load which the concrete can bear. Strength is considered as one of the most important and valuable properties of concrete.
When we talk about the strength of the concrete we are generally considered compressive strength, because we know that concrete is strong in compression and weak in tension. The concrete is mainly used for its compressive strength.
Factors Affecting the Strength of the Concrete
Following are the factors which affect the strength of the concrete.
1.1. Type of aggregates
Aggregates are the essential component part of the concrete. It will give volume to the concrete. The aggregates which are used in the manufacturing of the concrete should have high compressive strength so that it will produce concrete with good strength.
The aggregate which has sharp edges and rough texture will develop a strong bond between cement. Aggregates with a smooth texture and rounded shape result in a weaker bond between cement and aggregate.
1.2. Water cement ratio
The strength of the concrete depends upon the water-cement ratio used during the manufacturing of the concrete. The compressive strength of the concrete decreases with an increase in the water-cement ratio.
The optimum water content should be used to ensure the complete hydration of the cement.
1.3. Type of Cement
Cement is a binding material that is used to bind sand and aggregates with each other to form hardened concrete. Finer the size of the particles of the cement more will be the ultimate compressive strength.
The cement which has a higher composition of tricalcium silicate will develop concrete with higher strength.
1.4. Types of Admixture used
Admixtures are added to the concrete to achieve the desired property of the concrete. Admixtures in the concrete helps to improve the compressive strength.
1.5. Weather conditions
The weather conditions are also one of the factors which affect the compressive strength of the concrete. The concrete which is casted in the hot climate and the concrete which is casted in the cold climate has different values of compressive strength.
1.6. Curing conditions
It is very necessary that proper and adequate curing should be done to obtain maximum compressive strength of the concrete. Incomplete curing can cause a loss in the compressive strength of the concrete.
1.7. Method of Preparation
The method which is used in the preparation of the concrete also plays a vital role which also affects the overall strength of the concrete.
So that it is very necessary that skilled worker should work during the manufacturing of concrete otherwise we cannot achieve the desired strength in spite of using cement and aggregates in the concrete.
2. Impermeability of Harden Concrete
Impermeability is the one of the properties of hardened concrete which resists the flow of water through its pore. Permeability directly affects the durability of the concrete so it is very necessary that the concrete should be less permeable.
Excess of water-cement ratio may develop pores or cavities in the concrete which makes the concrete permeable.
3. Durability of Harden Concrete
Durability is also an important factor that affects the quality of the Hardened concrete. The durability of the concrete can be defined as the capacity of the concrete to bear all the forces of the deterioration.
Durability is also known as the period of existence of the concrete without getting adversely affected by Aggressive environmental conditions.
There are various causes that affect the durability of the hardened concrete which are Frost action, chemical reaction, alkali-aggregate reaction.
Frost action causes the deterioration of the concrete in cold climates. The reason of frost action is due to the freezing of water within the concrete pores in the extremely comfortable cold climate.
Concrete is liable to attack various acids and to attack various acids and salts which can destroy the concrete structure.
4. Dimensional Changes of Harden Concrete
Dimensional stability is also one of the properties of hardened concrete. The dimensional stability of the concrete is nothing but the behavior of the concrete under various forces.
Concrete is not a completely elastic material or completely plastic material. When the hardened concrete is loaded it undergoes deformation.
Permanent dimensional change in the hardened concrete is due to loading for a longer period which is generally known as Creep. Its value mainly depends upon the stress and the age of the concrete at the time of the loading.
5. Shrinkage of Harden Concrete
There are three types of shrinkage through which hardened concrete undergoes and which are important as per as its dimensional stability is concerned.
- Plastic shrinkage
- Drying shrinkage
- Thermal shrinkage
5.1. Plastic Shrinkage
Plastic shrinkage is a type of shrinkage in which the freshly placed concrete on the construction site undergoes till it sets completely.
This type of shrinkage is also commonly known as the initial Shrinkage and the excessive shrinkage in the concrete at its initial stage may affect the strength of the concrete.
The rate of plastic shrinkage mainly depends upon the rate of evaporation of water and the temperature during the casting of the concrete. The plastic shrinkage of the concrete is higher if the cement content in the concrete is more.
5.2. Drying Shrinkage
Drying shrinkage is a type of shrinkage which occurs after the concrete has completely set and hardens. There are some volume changes after setting of the cement which is because of the contraction of the gel structure.
The main cause of the drying shrinkage is the loss of the water content because of the evaporation from the freshly hardened concrete which is exposed to the environment.
5.3. Thermal Shrinkage
Thermal shrinkage is a type of shrinkage which occurs due to falling in the temperature of the concrete from the time it is placed upto it sets completely.