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Within the construction industry, nondestructive testing (NDT) technology plays an important role in ensuring that all materials and joining processes used during the fabrication and erection phases are of the highest quality. The applications of NDT technology within the construction industry are vast, ranging from building diagnoses to the testing of concrete structures.
Completely vs. Partially Destructive Testing
Immediately after concrete has hardened, it is crucial for construction workers to be able to adequately assess various properties of the structure without damaging it in the process. While NDT can also be applied to testing older structures, new concrete structures can be assessed by either utilizing completely non-destructive testing methods or partially destructive testing methods.
As indicated in their name, completely non-destructive testing methods eliminate the need to cause any damage to the concrete during the testing. These types of tests only require the surface of the concrete structure to be slightly damaged to obtain a sufficient sample for analysis. Comparatively, partially destructive tests, of which can include core, pullout and pull-off tests, on concrete structures require the surface of the structure to be damaged and subsequently repaired following analysis.
Types of NDT Methods for Concrete Analysis
In addition to the tests above, additional NDT methods for concrete analysis include visual inspection, permeability tests, penetration resistance tests, radiographic testing, half-cell electrical potential tests, tomographic modeling, impact echo testing and much more. The decision to utilize a specific NDT test over another is entirely dependent upon the material property being analyzed. For example, an ultrasonic pulse velocity test allows construction workers to obtain precise measurements on the sound velocity of the concrete to gain a better understanding of the compressive strength, uniformity and homogeneity of the concrete structure.
Each of the NDT methods used to analyze concrete structures utilizes a variety of NDT equipment. For example, ultrasonic pulse velocity tests will require the use of an ultrasonic pulse velocity meter, whereas penetration resistance tests can utilize a Windsor probe to assess the surface zone strength of a given concrete structure.
Assessing Equipment Integrity
It is crucial for construction companies to periodically assess the integrity of the equipment being used on the construction site. By utilizing NDT for equipment analysis, construction companies can ensure the safe operation of this equipment, as well as preemptively detect any defects before serious damage can occur.
SGS, which is an international inspection, verification, testing and certification company, is one company that offers highly effective NDT methods that construction companies can use to assess the integrity of their equipment. Recent advancements in sensory technology have allowed SGS to develop real-time and sensor-based monitoring systems that are integrated into their innovative NDT solutions. The NDT solutions provided by SGS monitor company assets 24/7; therefore, in the event of an emergency, construction management workers are notified of any defects immediately. As a result, companies can manage their maintenance investments more effectively, as well as minimize unwanted downtime that can occur during equipment repairs.
Future Directions of NDT in Construction
Despite the usefulness that NDT methods have had in providing a greater level of safety within the construction industry, these testing techniques are unfortunately associated with certain limitations. For example, current NDT methods used for bridge testing are often unable to determine the position and grouting of tendon ducts, which is a common problem in many bridges that were built between 1960 and 1980.
To overcome these limitations, several superior NDT methods have been proposed. For example, a variety of automated multipurpose scanner systems have been found to localize tendon ducts, as well as identify group defects at a highly accurate and rapid rate. Additionally, several climbing robotic systems, such as the Robot RoSY I and RoSy II have been enhanced with radar and impact-echo technology to provide a greater level of robustness and accuracy to building conservation and maintenance procedures.
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