The objective is to determine
the best concrete mix by evaluating concrete mix strength with available data
and take note of 7 days, 28 days and 72hrs, strength, batch and description.
evaluate concrete mix strength
with available data and take note of 7 days, 28 days and 72hrs, strength.
Based on the calculation: Strength f = Force/area
designed strength fd = f/factor
The above table fig 1 clearly shows the strength of material and the
results clearly differ between the Batch N,H,K than the code as they are tested
within different time intervals has seen in the first .
These results , show that the code differs by the percentage as shown in
fig 2 table. Where at 7 days being 67percent and at 28 days mostly 99 percent.Standard
deviation depends on the formula ((?Xi-?)/n)|^-2.
Calculation based on consideration of the whole data while calculating
the average and giving more safety factor.
The materials put under test exceeded the expected code strength value
as depicted in the comparison column which indicates it is good for the
However the standard deviation is normal for the entire batches except
in batch H-AA, H-BA, H-AB and H-BB which is relatively high showing that the strength varies in each
This however means it’s not entirely bad as they all exceed the either
expected design total strength.
The average mean strength of the code value expected to be 25% more than
it is but as shown most of the tested material within 7 days gained a strength extremely
higher than expected to be near to the full strength even after 28 days which increasingly
gives more safety factor for the building.
lt is evident from the data
that concrete given more time to set performs better than one which is not
given enough time ,however human error does not always guarantee a good batch