Experimental Investigation of Concrete Block Walls Compressive Strength Using a Non-destructive Test

The non-destructive test is an inexpensive measure of surface hardness that is used to determine the theoretical relationship between the strength of hardened concrete block walls and the rebound number of the hammer. This study analyzed the compressive strength of concrete block walls of a building using a non-destructive test. Data was collected using the impact method (Schmidt rebound hammer) on three sides of the building concrete block walls. The standard experimental procedure for impact method was followed and the analysis of the result were presented through tables and figure. The result shows that the rebound value (R) of the three sides for the concrete block walls were 17.21 N/mm² (CBW1), 15.01 N/mm² (CBW2) and 16.1 N/mm² (CBW3). The average compressive strength for all the CBW tested in relation to the R is 16.1 N/mm² which shows that the compressive strength of the concrete block walls is within the stipulated minimum compressive strength of 12.5 N/mm² for load-bearing concrete blockwork, using Ordinary Portland Cement and suitably graded fine and coarse aggregate in accordance to BSEN1971-1 2011. The study indicated that a non-destructive test using Schmidt rebound hammer is suitable for testing of the in-use building structures because it does not compromise the performance of component or structure being investigated and it's quality. The study concluded that the structure tested using the non-destructive test is safe and suitable for habitation.