LABORATORY ANALYSIS OF THE STANARD DEVIATION OF THE DIFFERENT GRADES OF CONCRETE. (M15, M20 and M25)

ABSTRACT

This project work is all about the laboratory analysis of the standard deviation of different grade of concrete. Talking about what standard deviation of a concrete is, standard deviation can simply be defining as the deviation of various laboratory values of concrete compressive strength from the standard compressive strength. The determination of the standard deviation of the concrete Grades (M15, M20, M25), was done by carrying out a compressive strength test on various cube samples, in this case I deal with 9 cube sample for each grades, which accumulated to the total sum of 27 cubes. This cube was casted according to the mix proportion ration gotten from the mix design for various grades. Ensure that the concrete mixer was done painstakingly and then casted into the mould to be used in the course of the Analysis (which is 100mm x 100mm). The cubes will be allowed to go through a curing period of 7-days, 21-days and 28-days, which will be applied for each grade involved. Then after each curing period elapsed for each grade accordingly then the cubes were subjected to a compressive strength test showing the values of the compressive strength of that cubes. After the results has been attained already, the standard deviation for each grades at each curing period will be obtaining and recorded. From my findings, I discovered that there is an enormous volatility in the compressive strength of concrete. In the sense that there is a notable deviation of the deviation of the compressive strength from the standard value for that particular grade. The deviation is actually still within the allowable standard deviation of the grades of concrete (M15, M20 and M25). So it can actually be inferred that the result for the standard deviation are actually positive and allowable according to the (IS -456 Table 8, clause 3.2.1.2).