Disclaimer: This calculator is intended for Educational purpose only and engineer should check the mix design manually before implementing on site.
- ‘*’ sign denotes required field quantities without which results will not be displayed.
- The mix design is calculated for crushed angular aggregates, any other shape of aggregate should be suitably adjusted in design.
- The mix design should be tested in laboratory as trial mix and suitable adjustments should be made for next trials if desired results are not achieved.
- This calculator shall only be used to design mix upto M90.
- For concrete mix design up to M65 check this calculator.
- Check out mix design tutorial in this video.
Concrete Mix Design Calculator
Mix Design Steps
Step 1 : Target Mean Strength
In order that not more than the specified proportion of test results are likely to fall below the characteristic strength, the concrete mix has to be proportioned for higher target mean compressive strength f’ck. The margin over characteristic strength is given by the following relation:
fck′=fck+1.65 ∗S or
fck′=fck+X
where S and X are taken from IS 10262:2019
Step 2: Approximate air content
Approximate amount of entrapped air is depended on nominal size of aggregate and is taken from the table 6 of IS 10262: 2019.
Step 3 : Water - cement ratio
Water cement ratio for high strength concrete depends on nominal size of aggregate and the target mean strength. Water cement ratio is taken from table 8 from IS 10262:2019.
Step 4 : Water content
The water content for high strength concrete mix design is calculated from Table 7 of IS 10262 : 2019. It depends on the maximum nominal size of aggregate.
The water content is also dependent on the workability of the mix and the standard values in the table are given for slump of 50mm and other slump values need to be suitably adjusted.
wcx=wc50 +((x-50))/25∗3/100∗wc50
If superplasticizers are used the water content needs to be reduced by appropriate percentage.
Step 5 : Cement content
Cement content is calculated using the relation between water content, water cement ratio and cement content, where:
w/c ratio = water content / cement content
Cementitious content is calculated by appropriately increasing the cement content and the cementitious materials are calculated from the cementitious content.
Step 6 : Aggregates
The ratio of coarse aggregate out of total aggregates is calculated from table 10 of IS 10262 2019.
This ratio depends on the maximum nominal size of aggregate and zone of fine aggregate used in the mix.
Further the fine aggregate percentage is calculated from the total.
For more workability the coarse aggregate might be reduced up to 5%.
Step 7 : Adjustment in Mix
Depending on the moisture content of the aggregates, the total water content is adjusted as the total water content found in STEP 4 is for SSD (saturated surface dry) condition.
