What Is Hardened Concrete | Properties of Hardened Concrete
Table of Contents
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 most durable construction materials.
Hardened concrete is concrete that is completely set and able to take the loads. In this article, we will go through the properties of Hardened concrete.
Also Read: All About Mix Design of Concrete | What Is Mix Design of Concrete | Nominal Mix | Design Mix
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 plays a vital role in the construction of any building. The strength of the concrete helps to identify whether the concrete can be used in construction or not.
The strength of the concrete is defined as the maximum amount of load which the concrete can bear. Strength is considered one of the most important and valuable properties of concrete.
The strength of the concrete gives the overall idea of the quality of the concrete and the materials used in the manufacturing of the concrete.
The concrete is tested for three types of strength which are compressive strength, tensile strength, and flexural strength.
When we talk about the strength of concrete we are generally considered compressive strength, because we know that concrete is strong in compression and weak in tension. Concrete is mainly used for its compressive strength.
The flexural strength of the concrete is defined as the measure of an under-reinforced concrete beam or slab to resist failure in bending.
Also Read: 19 Different Types of Slabs in Construction | What Is a Slab | Types of Slabs
Factors Affecting the Strength of the Concrete
The following are the factors that affect the strength of the concrete.
1.1. Type of Aggregates
Aggregates are an essential component part of 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 a rough texture will develop a strong bond with 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. The 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 help to improve the compressive strength.
1.5. Weather Conditions
Weather conditions are also one of the factors which affect the compressive strength of the concrete. The concrete which is cast in the hot climate and the concrete which is cast in the cold climate have 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 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 the 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 Hardened concrete. The durability of the concrete can be defined as the capacity of the concrete to bear all the forces of 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 hardened concrete which are Frost action, chemical reaction, and alkali-aggregate reaction.
Frost action causes the deterioration of the concrete in cold climates. The reason for 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.
Also Read: 22 Types of Beams | Standard Size of Beams
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 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 the cement which is because of the contraction of the gel structure.
The main cause of the drying shrinkage is the loss of 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 that occurs due to falling in the temperature of the concrete from the time it is placed up to it sets completely.
[su_box title=”FAQ” style=”default” box_color=”#333333″ title_color=”#FFFFFF” radius=”3″ class=”” id=””]
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. Hardened concrete is concrete that is completely set and able to take the loads.
What Makes Cement Harden?
Cement hardens when it comes into contact with water. This hardening is a process of crystallization. Crystals form (after a certain length of time which is known as the initial set time) and interlock with each other. Concrete is completely fluid before the cement sets, then progressively hardens.
What Causes Concrete to Harden?
The water causes the hardening of concrete through a process called hydration. Hydration is a chemical reaction in which the major compounds in cement form chemical bonds with water molecules and become hydrates or hydration products.
Hardened Concrete Test
Rebound Hammer Test (Schmidt Hammer Test) on Hardened Concrete. It is a non-destructive test performed on hardened concrete. A spring-loaded mass hits the concrete’s surface and scale measures how far the mass rebounds. The higher the rebound, the harder the concrete’s surface, and the greater the concrete’s strength
Strength of Hardened Concrete
Hardened concrete has a number of properties, including: Mechanical strength, in particular compressive strength. The strength of normal concrete varies between 25 and 40 MPa.
Can You Use Hardened Concrete?
Can I still use my cement if some has gone hard or there are lumps in the bag? No, we would not recommend that any cement containing lumps is used. Lumpy cement will not create a homogeneous mix. There is also a good chance it may not gain as much strength as you would expect.
Can Hardened Cement Be Reversed?
When the cement combines with water, the setting and hardening action results. This hardening can not be reversed. It is an irreversible process.
Does Hardened Concrete Absorb Water?
Yes, concrete does absorb water. The reason behind this is that concrete is a highly porous material that is made up of gravel, sand, cement and water. The final product appears hard but is full of pores.
Properties of Hardened Concrete
- Mechanical strength, in particular compressive strength. The strength of normal concrete varies between 25 and 40 MPa.
- Durability.
- Porosity and density.
- Fire resistance.
- Thermal and acoustic insulation properties.
- Impact resistance.
[/su_box]
[su_note note_color=”#F2F2F2 ” text_color=”#333333″ radius=”3″ class=”” id=””]
Like this post? Share it with your friends!
Suggested Read –
- What Is Bamboo Flooring | Bamboo Flooring Pros and Cons
- Types of Coffered Ceiling | What Is Coffered Ceiling | Coffered Ceiling Cost
- All About Retrofitting | What Is Retrofitting | Why Need Retrofitting | Advantages And Disadvantages of Retrofitting of Building
- What Are Hollow Bricks | Advantage of Hollow Bricks | Disadvantage of Hollow Bricks | Sizes of Bricks Blocks | How to Make Hollow Bricks
- What Is Fire Escape Staircases | Types of Fire Escaping Stairs | What Is the Importance of Fire Escape in the Building | What Are the Fire Staircase Requirements
[/su_note]