Project on Concrete Mix Design for various grades of Concrete

Calculate the Concrete Mix Design for M35 grade concrete with fly ash & M50 grade concrete without Fly ash.

#. AIM AND INTRODUCTION:

The concrete mix design involves determining the proportions of cement, fine aggregate (sand), coarse aggregate, and water to achieve the desired strength and workability. Here is a general mix design for M35 and M50 grade concrete:

#. To calculate the concrete mix design of M-35 grade with fly ash, the following steps can be followed:

• Determine the target strength (f'ck) of M-35, which is 35 MPa.

Target Mean Strength of Concrete (f’ck)=fck + 1.65 S

Where, fck= Characteristics comp. strength at 28 days

S = Standard Deviation (IS 10262:2009, Table-1)

• Determine the water-cement ratio (w/c) based on the required durability and workability. From Table-5 of IS 10262:2009, it can be calculated based on the exposure condition.

A typical w/c for M-35 is 0.45.

• Selection of water content: From Table-2 of IS 10262:2009
• Determine the quantities of cement, fine aggregate (sand), coarse aggregate (gravel), and fly ash needed for the desired volume of concrete. This can be done using the concrete mix proportioning method of your choice.
• Adjust the mix proportions as needed to achieve the target strength, workability, and durability.
• Verify the mix design by conducting trial mixes and compression tests.
• It's important to note that the mix proportions will vary depending on the specific characteristics of the materials used (e.g. the fineness of the fly ash, the grading of the aggregates, etc.), so the above steps are just a general guide. A professional engineer should be consulted to ensure that the mix design is appropriate for your specific project.
• Mix Calculation:

1. Volume of concrete = 1 m³
2. Volume of cement = (Mass of cement)/((Specific gravity of cement)*1000)

= 270

1. Volume of water = (Mass of water)/(Specific gravity of water*1000)
2. Volume of Chemical Admixture = (Mass of Chemical admixture)/(Specific Gravity of admixture * 1000)
3. Volume of aggregate (FA & CA) = (a-(b+c+d))
4. Mass of Course aggregate = e*Volume of CA * Specific gravity of CA * 1000
5. Mass of Fine Aggregate = e*Volume of FA * Specific gravity of FA*1000

Stipulation for Proportioning

• M35 Grade Concrete with Fly Ash:
• Types of cement: OPC 43 Grade conforming to IS 8112
• Cement: 430 kg/m3
• Fly Ash: 150 kg/m3(Confronting to IS 3812 part I)
• Fine Aggregate: 700 kg/m3
• Coarse Aggregate: 1050 kg/m3
• Water: 170 kg/m3

#. To calculate the concrete mix design of M-50 grade concrete without fly ash, the following steps can be followed:

• Determine the target strength (f'ck) of M-50, which is 50 MPa.
• Determine the water-cement ratio (w/c) based on the required durability and workability. A typical w/c for M-50 is around 0.35 to 0.45.
• Determine the quantities of cement, fine aggregate (sand), and coarse aggregate (gravel) needed for the desired volume of concrete. This can be done using the concrete mix proportioning method of your choice.
• Adjust the mix proportions as needed to achieve the target strength, workability, and durability.
• Verify the mix design by conducting trial mixes and compression tests.
• It's important to note that the mix proportions will vary depending on the specific characteristics of the materials used (e.g. the grading of the aggregates, etc.), so the above steps are just a general guide. A professional engineer should be consulted to ensure that the mix design is appropriate for your specific project. Additionally, while fly ash is not being used in this mix design, it may be added in the future to improve workability and durability.

M50 Grade Concrete without Fly Ash:

• Cement: 480 kg/m3
• Types of cement : OPC 43 Grade conforming to IS 8112
• Fine Aggregate: 675 kg/m3
• Coarse Aggregate: 1125 kg/m3
• Water: 165 kg/m3
• Specific Gravity of cement : 2.2

Please note that the mix design can vary depending on various factors such as the source and quality of materials, method of batching and mixing, and the weather conditions. This is just a general guide and it is recommended to consult a concrete expert for a more accurate mix design.