Comparative Analysis of Destructive and Non Destructive Testing Method of Concrete Strength using Compressive and Rebound Harmmer Testing Method
This work presents a study on the comparison between Destructive Compressive test and Non destructive testing techniques Schmidt Rebound Hammer . Tests moisture content, Sieve analysis, particle density for aggregate and cement paste, bulk density, standard consistency of cement, slump test were performed on both the aggregate and cement to compare their accuracy of both methods and test the quality of the material to be used for concrete casting and estimating the strength of concrete. Seventy samples cubes of 150 x 150 x 150mm were prepared using mix designs of 1 2 4 with a constant w c ratio of 0.45 and were tested at 7, 14, 21 and 28 days respectively. From the results, the rebound number increased from an average of 12 for 7days to an average rebound number of 17.7 for 28days which is similar to the increment in compressive strength from an average of 24.3 for 7days to an average of 32 for 28days which show that the increment in the strength is uniform but 5 difference in value obtained. The slump test was between 62 78mm. From the results of the analysis, it was observed that the strength obtained from destructive process conformed to targeted mix value, whereas that of the Rebound hammer was below these values. Statistical analysis of the results obtained showed that 5 difference exists between the results obtained from the two methods. Hence, there was no significant difference between the means of the two methods for both mixes at a 0.05 level of significance. Non destructive Testing is observed to be more economical as it required no electricity and can also be used directly in the field.
Concrete, Non Destructive Testing, Compressive Strength, Rebound Hammer, Destructive Testing method
Onyeka, F. C | Mama, B. O