frequently asked questions
BASIC INFORMATION ON ADVANCE NDT TESTING INSTRUMENTS AND TECHNOLOGY
On-site Evaluation of Concrete Strength is a main challenge in the condition assessment of existing infrastructure, or the quality control of new construction. normally prefer non-destructive and non-intrusive methods to avoid further damage to an already struggling structure. We have state of the art solutions for on-site evaluation of concrete strength.
COMPRESSION TEST ON CONCRETE CORES extracting concrete samples and testing for compressive strength is often considered the most cost-effective and most reliable solution. In this case, concrete core is taken from the existing structure. The core needs cutting (sawing) and surface preparation. The core is then tested.for compressive strength.
PULL-OUT TEST is that the tensile force required to pull a metal disk, together with a layer of concrete, from the surface to which it is attached, is related to the compressive strength of the concrete. The pull-out test is normally used for early diagnosis of strength problems.
REBOUND HAMMER works based on the rebound principle, and consist of measuring the rebound of a spring driven hammer mass after its impact with concrete.
ULTRASONIC PULSE VELOCITY (UPV) is an effective method for quality control of concrete materials, and detecting damages in structural components.
The UPV methods have been traditionally used for the quality control of materials the test has been widely accepted in testing concrete materials. The test procedure has been standardized as “Standard Test Method for Pulse Velocity through Concrete” (ASTM C 597, 2016).
The concept behind the technology is measuring the travel time of acoustic waves in a medium, and correlating them to the elastic properties and density of the material.
GROUND PENETRATING RADAR (GPR) provides a cost-effective, non-destructive and reliable tool for scanning and imaging of sub-surface defects, voids, and objects multipurpose nature of ground penetrating radar The method has been standardized by ASTM D6432. Concrete Scanning using for.
- Locating and Mapping embedded steel reinforcement (steel bars, prestressing tendons)
- Predict the thickness of concrete elements
- Locate potential defects and voids such as delaminated areas
- Mapping subsurface delamination in bridge deck
- Reinforcement (steel rebar, prestressing tendons) locations
- Identify the location of sub-surface defects in soil
- Identify the location of water pipes, power and storage tanks, etc.
REBAR CORROSION X Cell is a non-destructive testing device for fast, reliable, and accurate detection and analysis of corrosion in reinforced concrete structures, complete with accurate contour mapping used for.
- Detection of corrosion in reinforcement.
- Measurement of rebar corrosion rate.
- Evaluation of corrosion potential of rebar
- Measurement of in-situ electrical resistivity.
- Assessment of concrete durability.
- Rehabilitation and repair of concrete structures etc.
What is structural retrofitting?
Structural Retrofitting of Existing Buildings, that requires modifications to the structural elements of a building to reduce the risk of future damage and to protect inhabitants.
What is the difference between repair and retrofitting?
Repair: Actions taken for repairing up superficial defects and doing the finishes. Retrofitting: Actions for upgrading the seismic restoring of an existing building structure.
What are the types of retrofitting?
- Adding New Shear Wall.
- Adding Steel Bracing.
- Wall Thickening Technique.
- Base Isolation Technique.
- Mass Reduction Technique.
- Jacketing Method.
- Fiber Reinforced Polymer (FRP)
- Epoxy Injection Method.
What is the process of retrofitting?
The process of retrofitting involves the careful balancing of different elements and their effects on the overall performance of a building. A change in one part of a structure can affect another, and sometimes this is only likely after irreversible defects have occurred.
What are the types of cracks?
The most common types of cracks are organised in the following
- Plastic Settlement.
- Plastic Shrinkage.
- Early Thermal Contraction.
- Long-term Drying Shrinkage.
- Crazing.
- Corrosion of Reinforcement.
- Alkali-aggregate Reaction
What is the need for structural repair?
Need for Repair and Rehabilitation of Concrete Structure
Faulty design of the structure. Improper execution and bad workmanship. Extreme weathering and environmental conditions. A high degree of chemical attack.
As corrosion is the primary driver of many repairs, we have utilized a number of corrosion protection systems, from proper repair techniques and mitigating admixtures; passive protection with anodes; to active impressed current cathodic protection systems.