Introduction

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.

Objectives

evaluate concrete mix strength

with available data and take note of 7 days, 28 days and 72hrs, strength.

Calculations/Results

fig 1a

fig 2

Observations

Based on the calculation: Strength f = Force/area

designed strength fd = f/factor

of safety

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

building safety.

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

tested material

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.

Conclusion

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

of concrete.

References