A comparative analysis between Rebound
Hammer and Pullout method in testing concrete was conducted
in this study. Experimental analysis was carried out to
compare the correctness between the two testing method in
estimating the strength of concrete. Different cube (cubes of
175 x 175 x 175) samples were prepared using two mix designs
of 1:2:4 and 1:3:6 with a constant w/c ratio of 0.45 and were
tested at 7, 14, 21 and 28 days. The rebound hammer readings
had a correlation coefficient of 0.695 while the pullout had a
correlation coefficient of 0.725 for the 1:2:4 mix and the
rebound hammer readings for 1:3:6 was 0.724 and that for the
pullout was 0.675. From the results obtained, it is observed that
the non-destructive testing methods were correlated with the
compressive strength results which showed that a higher
correlation existed between the Rebound Hammer and the
compressive strength than the Pullout. Statistical analysis of
the results obtained showed that there was no significant
difference between the means of the two methods for both mix
at a 0.05 level of significance. However, rebound hammer
method can be recommended as it provides a quicker, lessexpensive means of checking the uniformity of concrete even
though it shows less sensitivity as concrete matures, unlike the
Pullout test in which measuring strength is affected by the
arrangement of the embedded insert, the dimensions of bearing
ring, the depth of embedment, the concrete age and the type of
aggregates uses in concrete.