Different types of Concrete test, explain in details step by step procedure with examples.

There are several tests that can be performed on concrete to evaluate its quality, properties, and performance, including:

1. Compressive Strength Test: measures the compressive strength of concrete by applying a compressive load to cylindrical or cubic concrete specimens until they fail.
2. Slump Test: measures the consistency or workability of freshly mixed concrete by determining the height of the concrete after being molded into a cone-shaped form.
3. Air Content Test: measures the amount of entrained air in freshly mixed concrete, which is important for proper curing and freeze-thaw durability.
4. Setting Time Test: measures the time it takes for concrete to set and harden to a solid state.
5. Absorption Test: measures the ability of concrete to absorb water, which can impact its durability and freeze-thaw resistance.
6. Flexural Strength Test: measures the ability of concrete to resist bending and breaking under a load, which is important for applications such as beams and slabs.
7. Tensile Strength Test: measures the ability of concrete to resist tension, which is important for understanding its behavior under stress.
8. Modulus of Elasticity Test: measures the elasticity of concrete, which can be used to calculate deflections and deformations.
9. Chloride Ion Penetration Test: measures the resistance of concrete to chloride ion penetration, which is important for understanding its durability in coastal and marine environments.

These tests are important tools for engineers and contractors to understand the properties and performance of concrete and to ensure that it meets the required standards and specifications for a particular application.

1. Compressive Strength Test

The compressive strength test is a fundamental test that measures the ability of concrete to resist compressive stress and crushing forces. The test is performed by applying a compressive load to cylindrical or cubic concrete specimens, typically with a diameter of 150mm and a height of 300mm, until they fail.

Test Procedure:

1. Obtain cylindrical or cubic concrete specimens of a standard size, typically with a diameter of 150mm and a height of 300mm.
2. Allow the specimens to cure for a specified period of time, typically 7, 14, or 28 days, in a controlled environment at a temperature of 20°C to 25°C and a relative humidity of 50%.
3. Place the concrete specimens in compression testing machine, ensuring that they are properly aligned and centered.
4. Apply a compressive load to the specimens, at a constant rate of deformation, until they fail.
5. Record the maximum compressive load reached before failure, and calculate the compressive strength of the concrete using the formula: compressive strength = maximum load/cross-sectional area of the specimen.

The compressive strength of concrete is typically expressed in megapascals (MPa) or pounds per square inch (psi), and is considered to be one of the most important properties of concrete. The compressive strength of concrete can be used to evaluate its quality, predict its behavior under stress, and compare it to the design strength specified for a particular application.

Examples:

1. For residential construction, the compressive strength of concrete is typically in the range of 20 to 40 MPa (2,900 to 5,800 psi).
2. For commercial and industrial construction, the compressive strength of concrete may be higher, typically in the range of 40 to 80 MPa (5,800 to 11,600 psi).
3. For high-performance or high-strength concrete, the compressive strength may be even higher, typically in the range of 80 to 100 MPa (11,600 to 14,500 psi) or higher.

In conclusion, the compressive strength test is a critical test that provides important information about the quality, strength, and performance of concrete, and is an essential tool for engineers and contractors to ensure that concrete meets the required standards and specifications for a particular application.

2. Slump Test

The slump test is a simple and commonly used test to measure the workability or consistency of freshly mixed concrete. The test is performed by measuring the height of the concrete after it has been poured into a cone-shaped mold and allowed to settle. The height of the settled concrete is compared to the original height of the concrete in the mold to determine the slump, which is an indicator of the workability of the concrete.

Test Procedure:

1. Fill a slump cone with freshly mixed concrete, compacting it in three equal layers and tamping each layer 25 times with a rod.
2. Lift the slump cone vertically, leaving the concrete inside the mold.
3. Measure the height of the concrete inside the mold.
4. Measure the height of the settled concrete after a few minutes.
5. The difference between the height of the concrete in the mold and the height of the settled concrete is the slump, which is typically measured in millimeters.

The slump test provides an estimate of the workability of concrete, which is an important factor in determining the ease of placement and finishing of the concrete. A high slump, typically in the range of 100-180mm, indicates a more fluid and workable concrete, while a low slump, typically in the range of 0-50mm, indicates a stiffer and less workable concrete.

Examples:

1. For normal weight concrete, a slump of 50-100mm is typical for standard mix designs.
2. For self-compacting concrete, a slump of 200-450mm is typical, indicating a highly fluid and workable concrete.
3. For high-performance concrete, a slump of 50-100mm is typical, indicating a stiffer and less workable concrete that is designed for high strength and durability.

In conclusion, the slump test is a simple and useful test that provides important information about the workability and consistency of freshly mixed concrete, and is an essential tool for engineers and contractors to ensure that concrete is properly mixed and meets the required standards and specifications for a particular application.

3. Air Content Test

The air content test, also known as the air entrainment test, is used to measure the amount of entrained air in freshly mixed concrete. Entrained air is intentionally added to concrete to improve its durability and resistance to freeze-thaw damage, and to reduce cracking and segregation of the concrete mix.

Test Procedure:

1. Fill a measuring container, such as a pressure gauge or volumetric flask, with a sample of freshly mixed concrete.
2. Seal the container and shake it to allow the air bubbles to escape from the concrete.
3. Record the volume of the concrete in the container.
4. Repeat the process with the same sample after it has been allowed to stand for a few minutes.
5. Measure the volume of the entrained air by subtracting the final volume of the concrete from the initial volume.

The air content test provides a quantitative measure of the amount of entrained air in the concrete mix, expressed as a percentage of the total volume of the concrete. The air content is typically in the range of 3-7% for normal weight concrete, with higher air contents required for concrete exposed to severe weather conditions.

Examples:

1. For normal weight concrete, a typical air content is in the range of 3-5%.
2. For lightweight concrete, a higher air content of 5-7% is typical to improve the insulation properties and reduce the weight of the concrete.
3. For high-performance concrete, a lower air content of 2-3% is typical to improve the strength and durability of the concrete.

In conclusion, the air content test is an important tool for engineers and contractors to ensure that concrete has the correct amount of entrained air for its intended use. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application.

4. Setting Time Test

The setting time test of concrete is used to determine the time it takes for the concrete to set, or reach an initial stage of hardening, after it has been mixed with water. This test is important for determining the workability and placement of the concrete, and for ensuring that the concrete will set within the required time frame for a particular application.

Test Procedure:

1. Prepare two standard Vicat apparatus consisting of a plunger and a needle.
2. Fill a cylindrical mold with the concrete mix.
3. Insert the needle of the Vicat apparatus into the center of the concrete.
4. Apply a standard load to the plunger of the Vicat apparatus, and record the time it takes for the needle to penetrate the surface of the concrete.
5. Repeat the process with the second Vicat apparatus at a different time interval to confirm the setting time.

The setting time of concrete is typically measured in hours or minutes after mixing with water, and is determined as the time at which the concrete will not deform significantly when subjected to a standard load. The initial setting time is defined as the time it takes for the concrete to begin to stiffen, while the final setting time is defined as the time it takes for the concrete to reach a hardened state.

Examples:

1. For normal weight concrete, the initial setting time is typically in the range of 30-60 minutes, while the final setting time is in the range of 3-6 hours.
2. For high-performance concrete, the initial setting time is typically shorter, in the range of 15-30 minutes, while the final setting time is still in the range of 3-6 hours.
3. For self-compacting concrete, the setting time may be longer, in the range of 4-6 hours, to allow for proper placement and consolidation of the concrete mix.

In conclusion, the setting time test is an important tool for engineers and contractors to determine the workability and placement of concrete, and to ensure that the concrete sets within the required time frame for a particular application. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application.

4.1 Initial setting time test of concrete

The initial setting time test of concrete determines the time it takes for the concrete to reach its initial stage of hardening after mixing with water. This test is important for determining the workability and placement of the concrete, and for ensuring that the concrete will set within the required time frame for a particular application.

Test Procedure:

1. Prepare a Vicat apparatus consisting of a plunger and a needle.
2. Fill a cylindrical mold with the concrete mix.
3. Insert the needle of the Vicat apparatus into the center of the concrete.
4. Apply a standard load to the plunger of the Vicat apparatus, and record the time it takes for the needle to penetrate the surface of the concrete.
5. Repeat the process to confirm the initial setting time.

The initial setting time of concrete is typically measured in minutes after mixing with water, and is determined as the time at which the concrete will not deform significantly when subjected to a standard load. The initial setting time is an important indicator of the workability and placement of the concrete, and helps to ensure that the concrete will set within the required time frame for a particular application.

Examples:

1. For normal weight concrete, the initial setting time is typically in the range of 30-60 minutes.
2. For high-performance concrete, the initial setting time is typically shorter, in the range of 15-30 minutes.
3. For self-compacting concrete, the initial setting time may be longer, in the range of 1-2 hours, to allow for proper placement and consolidation of the concrete mix.

In conclusion, the initial setting time test is an important tool for engineers and contractors to determine the workability and placement of concrete, and to ensure that the concrete sets within the required time frame for a particular application. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application.

4.2 Final Setting Time Test of concrete

The final setting time test of concrete determines the time it takes for the concrete to reach its final stage of hardening after mixing with water. This test is important for determining the curing time of the concrete, and for ensuring that the concrete will achieve its required strength and durability.

Test Procedure:

1. Prepare a Vicat apparatus consisting of a plunger and a needle.
2. Fill a cylindrical mold with the concrete mix.
3. Insert the needle of the Vicat apparatus into the center of the concrete.
4. Apply a standard load to the plunger of the Vicat apparatus, and record the time it takes for the needle to penetrate the surface of the concrete.
5. Repeat the process to confirm the final setting time.

The final setting time of concrete is typically measured in hours after mixing with water, and is determined as the time at which the concrete has reached its final stage of hardening and will not deform significantly when subjected to a standard load. The final setting time is an important indicator of the curing time of the concrete, and helps to ensure that the concrete will achieve its required strength and durability.

Examples:

1. For normal weight concrete, the final setting time is typically in the range of 3-4 hours.
2. For high-performance concrete, the final setting time is typically shorter, in the range of 1-2 hours.
3. For self-compacting concrete, the final setting time may be longer, in the range of 6-8 hours, to allow for proper curing and consolidation of the concrete mix.

In conclusion, the final setting time test is an important tool for engineers and contractors to determine the curing time of concrete, and to ensure that the concrete achieves its required strength and durability. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application.

5. Water Absorption Test

The water absorption test of concrete measures the amount of water that a concrete sample can absorb. This test is important for determining the durability and resistance to water of the concrete, and helps to ensure that the concrete will perform as expected in its intended environment.

Test Procedure:

1. Prepare a sample of concrete, either by cutting a piece from a concrete structure or by making a new sample.
2. Clean the surface of the concrete sample thoroughly to remove any dirt, oil, or other contaminants.
3. Weigh the concrete sample to the nearest 0.1 g.
4. Immerse the concrete sample in water for 24 hours.
5. After 24 hours, remove the concrete sample from the water and wipe it dry with a cloth.
6. Re-weigh the concrete sample to the nearest 0.1 g.
7. Calculate the water absorption by subtracting the initial weight of the sample from the final weight, and divide the result by the initial weight.

The water absorption of concrete is expressed as a percentage of the initial weight of the sample. The lower the water absorption, the more water-resistant and durable the concrete is considered to be.

Examples:

1. For normal weight concrete, the water absorption is typically in the range of 10-15%.
2. For high-performance concrete, the water absorption is typically lower, in the range of 5-10%.
3. For lightweight concrete, the water absorption is typically higher, in the range of 20-25%.

In conclusion, the water absorption test is an important tool for engineers and contractors to evaluate the durability and resistance to water of concrete. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application. The results of the water absorption test can also be used to determine the most appropriate type of concrete for a particular project, and to ensure that the concrete will perform as expected over its expected service life.

6. Flexural Strength Test

The flexural strength test of concrete, also known as the “three-point bend test,” measures the ability of concrete to resist bending. This test is important for determining the overall strength and toughness of concrete, and is often used to assess the quality and consistency of a concrete mix.

Test Procedure:

1. Prepare a sample of concrete, either by cutting a piece from a concrete structure or by making a new sample.
2. Clean the surface of the concrete sample thoroughly to remove any dirt, oil, or other contaminants.
3. Place the concrete sample in a testing machine, and apply a load at the center of the sample through two loading points located at a specified distance apart.
4. Apply the load gradually and continuously, and record the load at the point of maximum deflection.
5. Repeat the test several times to obtain an average value for the flexural strength of the concrete sample.

The flexural strength of concrete is expressed in pounds per square inch (psi) or megapascals (MPa). The results of the flexural strength test are used to evaluate the overall strength and toughness of concrete, and to assess the quality and consistency of a concrete mix.

Examples:

1. For normal weight concrete, the flexural strength is typically in the range of 300-500 psi (2-3.5 MPa).
2. For high-performance concrete, the flexural strength is typically higher, in the range of 500-800 psi (3.5-5.5 MPa).
3. For lightweight concrete, the flexural strength is typically lower, in the range of 200-400 psi (1.5-2.5 MPa).

In conclusion, the flexural strength test is an important tool for engineers and contractors to evaluate the overall strength and toughness of concrete. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application. The results of the flexural strength test can also be used to determine the most appropriate type of concrete for a particular project, and to ensure that the concrete will perform as expected over its expected service life.

7. Flexural Strength Test

The flexural strength test of concrete, also known as the “three-point bend test,” measures the ability of concrete to resist bending. This test is important for determining the overall strength and toughness of concrete, and is often used to assess the quality and consistency of a concrete mix.

Test Procedure:

1. Prepare a sample of concrete, either by cutting a piece from a concrete structure or by making a new sample.
2. Clean the surface of the concrete sample thoroughly to remove any dirt, oil, or other contaminants.
3. Place the concrete sample in a testing machine, and apply a load at the center of the sample through two loading points located at a specified distance apart.
4. Apply the load gradually and continuously, and record the load at the point of maximum deflection.
5. Repeat the test several times to obtain an average value for the flexural strength of the concrete sample.

The flexural strength of concrete is expressed in pounds per square inch (psi) or megapascals (MPa). The results of the flexural strength test are used to evaluate the overall strength and toughness of concrete, and to assess the quality and consistency of a concrete mix.

Examples:

1. For normal weight concrete, the flexural strength is typically in the range of 300-500 psi (2-3.5 MPa).
2. For high-performance concrete, the flexural strength is typically higher, in the range of 500-800 psi (3.5-5.5 MPa).
3. For lightweight concrete, the flexural strength is typically lower, in the range of 200-400 psi (1.5-2.5 MPa).

In conclusion, the flexural strength test is an important tool for engineers and contractors to evaluate the overall strength and toughness of concrete. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application. The results of the flexural strength test can also be used to determine the most appropriate type of concrete for a particular project, and to ensure that the concrete will perform as expected over its expected service life.

8. Modulus of Elasticity Test

The modulus of elasticity test of concrete is a measure of the stiffness and elasticity of concrete. It is an important property that affects the behavior of concrete under loads, such as cracking and deformation. The modulus of elasticity is also used to calculate the deflection of concrete members and to determine the amount of reinforcement required to resist specific loads.

Test Procedure:

1. Prepare a concrete sample by casting a cylinder or beam and allowing it to cure for a specified time period.
2. Clean the surface of the concrete sample thoroughly to remove any dirt, oil, or other contaminants.
3. Place the concrete sample in a testing machine, and apply a load at a specified rate.
4. Measure the deformation of the concrete sample as the load is applied, and record the values.
5. The modulus of elasticity is calculated from the slope of the stress-strain curve obtained from the test.

The modulus of elasticity is expressed in pounds per square inch (psi) or megapascals (MPa). The results of the modulus of elasticity test can be used to evaluate the quality and consistency of a concrete mix, and to compare different concrete mixes to determine the most appropriate type of concrete for a particular project.

Examples:

1. For normal weight concrete, the modulus of elasticity is typically in the range of 3 to 7 million psi (20 to 50 GPa).
2. For high-performance concrete, the modulus of elasticity is typically higher, in the range of 7 to 11 million psi (50 to 75 GPa).
3. For lightweight concrete, the modulus of elasticity is typically lower, in the range of 2 to 5 million psi (15 to 35 GPa).

In conclusion, the modulus of elasticity test is an important tool for engineers and contractors to evaluate the stiffness and elasticity of concrete. The results of the test can be used to determine the most appropriate type of concrete for a particular project, to calculate deflection and reinforcement requirements, and to ensure that the concrete will perform as expected over its expected service life. The test provides valuable information about the quality and consistency of the concrete mix, and helps to ensure that the concrete meets the required standards and specifications for a particular application.

9. Chloride Ion Penetration Test

The Chloride Ion Penetration Test of concrete is a test used to determine the susceptibility of concrete to chloride-ion-induced corrosion of reinforcing steel. Chloride ions can penetrate the concrete surface and reach the reinforcement, causing corrosion and reducing the service life of the structure. The test is used to assess the resistance of concrete to chloride ion penetration and to evaluate the effectiveness of treatments to reduce the rate of chloride ion penetration.

Test Procedure:

1. Obtain a cylindrical concrete specimen of a specific size, with a smooth surface and homogeneous composition.
2. Clean the surface of the concrete specimen thoroughly to remove any dirt, oil, or other contaminants.
3. Immerse the concrete specimen in a sodium chloride solution of a known concentration for a specified period of time.
4. Remove the concrete specimen from the solution, and wash it thoroughly with distilled water.
5. Cut the specimen into thin slices, and prepare polished sections for examination.
6. Observe and measure the depth of penetration of chloride ions into the concrete specimen, and calculate the chloride ion penetration rate.

Example: A common example of the Chloride Ion Penetration Test is the ASTM C1202, Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration. In this test, a current is passed through the concrete specimen while it is immersed in the sodium chloride solution, and the resistance of the concrete to the flow of current is measured. The test provides a quantitative measure of the chloride ion penetration into the concrete.

Uses in construction industry: The Chloride Ion Penetration Test is used in the construction industry to determine the durability and service life of concrete structures. It is used to evaluate the performance of concrete exposed to various environmental conditions and to select the most appropriate type of concrete for different construction projects. The test results can be used to optimize the design of concrete mixes, to improve the quality of concrete production, and to monitor the performance of concrete during its service life.