Frequently Asked Questions
The Half-Cell Corrosion Potential Test is a popular NDT method used to assess corrosion activity in reinforced concrete structures. The test provides valuable information on the likelihood of active corrosion in concrete, helping engineers and maintenance professionals to make informed decisions about structural health and maintenance priorities.
Cracks happen for a wide range of reasons. Two important characteristics of concrete crack is the crack width and crack depth. The width of a crack can normally be measured using a ruler or crack gage. The depth of crack requires Ultrasonic Pulse Velocity Testing . Crack depth measurement is important when evaluating the durability performance of a structure.
There are a wide variety of NDT methods that can be implemented depending on the specifications of the assignment. In general, Ultrasonic Pulse Velocity (UPV) involve sending ultrasonic waves through concrete to detect changes in density and identify anomalies. The velocity of the waves can indicate the concrete's uniformity and potential issues such as voids, cracks, or variations in composition. Ultrasonic Pulse Echo (UPE) is used to detect the depth and location of flaws such as delaminations or voids. Rebound Hammer (RH) measures the surface hardness of concrete by rebounding a mass off the surface.
Several methods can be employed to detect and assess voids and defects in concrete. Ground Penetrating Radar (GPR) is a useful preliminary test method as it does a excellent job identifying target locations for voids and other defects. Further test methods can then be applied to better analyse and determine the type of defect and its severity, to deliver a comprehensive investigation.
Ultrasonic Pulse Velocity (UPV) is a Non-Destructive Testing (NDT) method used to assess the quality, integrity, and uniformity of concrete. UPV involves sending ultrasonic waves through concrete to detect changes in density and identify anomalies. The velocity of the waves can indicate the concrete's uniformity and potential issues such as voids, cracks, or variations in composition.
The primary purpose of the the Schmidt Hammer (RH) is to determine the surface hardness of the concrete. In some circumstances the SonReb method can be applied which combines Ultrasonic Pulse Velocity (UPV) readings and rebound numbers to estimate the compressive strength of a concrete component. However this is only an estimation and not always a reliable alternative.
Ground Penetrating Radar (GPR) is the most effective way to locate steel rebar in typical concrete slab and wall and wall settings. A high frequency device, such as 1000 MHz or more is prefered for this application. Additionally a common covermeter can also be useful tool to locate rebar depending on the rebar layout.
Ultrasonic Pulse Echo (UPE) is the prefer NDT method for this situation. It uses acoustic stress waves to study the properties of subsurface layers, which produce imaging that indicates the location of the backend reflection thus determine the thickness of a concrete element.
There are certain limitations when it comes to performing NDT methods. Some methods work better with specific materials, and environmental factors such as temperature, humidity, and surface condition. In cases where access is limited or obstructed, conducting the test may be challenging or impossible.
There are a wide range of circumstances that warrant Non-Destructive Testing. Visible defects such as cracks and corrosion are the most common reason why asset owners turn to NDT methods, however routine maintenance practices and even forensic investigations are other practical reason why NDT methods might be selected for a job scope
The depth of a pile is can be estimated by performing a Pile Integrity Test (PIT). This is carried out by striking the pile head with a light hand-held hammer and recording the response of the pile using a motion transducer coupled to the pile head.
Non-Destructive Testing (NDT) plays a crucial role in asset management at industrial facilities as NDT's can be conducted in shorter time frames then traditional invasive methods. They provide valuable information about the condition and integrity of assets such as; early detection of defects, asset lifespan, optimizing maintenance planning, documentation data and overall investment protection.
Cross Hole Sonic Logging (CSL) is commonly used for assessing the integrity and quality of deep foundation elements such as piles. However, not all types of piles are suitable for CSL testing. CSL requires access to the interior of the pile, therefore the construction design must include the installation of access tubes or pipes that connect the top and bottom of the pile.
Yes, in general it is significantly more advantageous for clients to commision multiple NDT tests to be taken on the same component. Because each test method has its own level of uncertainty and limitations, it is prefered to have numerous tests taken to form a more comprehensive report.
Non-Destructive Testing (NDT) techniques can be beneficial in forensic investigations, depending on the nature of the investigation and the materials involved. In somecase, NDT provide necessary information that can reveals details on how well concrete was casted, as well as confirming the use of rebar.
Ground Penetrating Radar (GPR) is not the best tool to confirm the presence of corrosion whereas it can provide a preliminary opinion to further investigate using other NDT methods. Depending on the quality of the scans, certain GPR imaging can strongly suggest the presence of corrosion.
Several Non-Destructive Testing (NDT) methods are commonly used to assess the depth and quality of deep foundations, such as; Pile Integrity Testing (PIT), Crosshole Sonic Logging (CSL), Thermal Integrity Profiling (TIP) and Dynamic Tests such as Pile Driving Analyzer.
Parallel Seismic Test is frequently used to assess the depth of existing foundations. Guided Waves and Cross Hole Sonic Logging Tests can also be used to evaluate the unknown depth of existing concrete piles depending on the situation.