STATISTICAL ANALYSIS BETWEEN ACTUAL AND NOMINALFAILURESTRENGTH OF PRESCRIBED MIXES

ABSTRACT

This study is to determine the statistical variability of concrete mixes fromnominal values. The values gotten from this research work are used to compare the standard mixes alreadybeen used in construction. A statistical analysis between the actual and nominal breaking strengths of the prescribedmixtures was carried out to verify the differences from the standard strengths of the nominal mixtures currently in use and to compare it with the results of this research workwithrefrences made to previous work done. This study was conducted to investigate the compressive strength of concretecubeproduced in the laboratory. The practical aspect of this study saw the use of five different mixtures. The mixing ratio is M5, M10, M15, M20, M25. Therefore, 60 cubes (100x100)were cast using different water-cement ratios for each mix. After the results for the five(5)different mix were gotten I then employed different statistical approach to the values gottenfrom the lab in other to properly compare the nominal mixes from the actual vlues gotten. Mixes like M5 and M10 was noticed while carrying out the experiment that the cement was low the average value gotten for M5 and M10 at 28days are 11.67 and 14.27N/mm2respectively and then relative to grades like M20 and M25 which results were 23.99and28.38N/mm2 . From the results gotten in this research work we see that for each mix that was usedwehave that the deviation from nominal values were both positive and negative but not totallyshifting or digressing away from the original mixes strength giving us a solid groundastowhy the prescribed nominal mixes are standard.