Non-Destructive Testing

A Schmidt hammer, also known as a Swiss hammer or a Rebound Hammer or concrete hammer test, is a device to measure the elastic properties or strength of concrete or rock, mainly surface hardness and penetration resistance.
 

It can also be used for assessing the quality of the concrete in relation to standard requirements, and assessing the quality of one element of concrete in relation to another.

An Ultrasonic Pulse Velocity (UPV) Test is an in-situ, nondestructive test to check the quality of concrete and natural rocks. In this test, the strength and quality of concrete or rock is assessed by measuring the velocity of an ultrasonic pulse passing through a concrete structure or natural rock formation.
 

Higher velocities indicate good quality and continuity of the material, while slower velocities may indicate concrete with many cracks or voids.

Core Testing is one of the very reliable tests adopted for checking the compressive strength of the ‘In situ concrete”. Other physical properties such as density, water absorption and chemical properties such as cement content, chloride and sulphate content can also be measured from the core.
 

This test is a partially destructive in nature and is used to co-relate the various other properties of the concrete such as UPV, electrical resistivity, rebound number etc. It is customary to take cores of 4 inch diameter for compressive strength determination.

For Strength Evaluation of Bridges,  Buildings & Other Structures

Corrosion is a natural process that occurs when a structure is exposed to elements like CO2 or chloride, which can penetrate the concrete all the way to the steel reinforcement. This can have serious durability and safety consequences, which is why it is important to monitor corrosion using an accurate and trusted method.

The Half-Cell Potential Test is the only corrosion monitoring technique standardized in ASTM C876 – 15: Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete.

Concrete carbonation is one of the main causes of reinforcement corrosion on the building facades which are exposed to moisture, rainfall and shaded from sunlight. Carbonation Test measures the depth of deterioration in concrete.
 

The phenolphthalein indicator solution is applied to a fresh fracture surface of concrete. The inner portion turns purple. The outer depth which remains colourless inidcates carbonation.

Covermeter is a device used to determine the precise concrete cover depth and to pinpoint the exact location of the rebars in the concrete. Hitting a rebar while boring into reinforced concrete can damage the drilling instrument or even weaken the concrete structure.

Therefore, it is vital to know the cover depth and precise location of the rebars before starting the maintenance work. Due to the cost-effective design, this pulse-induction method is one of the most commonly used solutions.