Abstract:
The concept of nondestructive
testing (NDT) is to obtain material properties “in place”
specimens without the destruction of the specimens and to do the structural health monitoring.
NDT using Rebound hammer, Ultra pulse velocity, Halfcell
potential, core cutter, carbonation
depth, rebar locator, Rapid chloride penetration test, electric resistivity meter test and vibration
base analysis by data analoger are very popular and highly effective in conducting structural
health monitoring. The structure can be investigated by using a visual inspection, NDT,
laboratory and field test performance. In this article a review of these tests have been provided
to conduct effective structural health monitoring of a RCC structure.
The estimation of mechanical properties of concrete can be carried out by several methods;
destructive and nondestructive.
In this context, the crushing of the samples is the usual
destructive test to determine the concrete strength. The rebound hammer test and the ultrasonic
device are used in the field of nondestructive
tests to determine respectively the compression
strength and the ultrasonic pulse velocity (UPV) in the concrete. In this work, eight concrete
compositions were used to prepare cylindrical specimens (16 cm x 32 cm) by varying the water/
cement ratio and the cement dosage. An experimental study was conducted to determine the
compressive strength of concrete by destructive (compression) and nondestructive
(rebound
hammer) tests at different ages (7, 14 and 28 days). In addition, the influence of several factors
on the modulus of elasticity determined by pulse velocity test was investigated. These factors
mainly included the age of concrete and the water/ cement ratio. The results showed that the
difference between the resistance values obtained by destructive and nondestructive
methods
decreases with increasing age of concrete. The dynamic modulus of elasticity increases with the
curing time of the concrete until the age of three months. In addition, a simplified expression
has been proposed to estimate the rebound number from the value of the dynamic modulus of
elasticity determined by pulse velocity test.
