Non-Destructive Testing (NDT) is essential for assessing the condition of buildings, bridges, and other civil structures without causing any damage. It helps detect internal flaws, monitor deterioration, and verify construction quality across various stages. S K Sharma Engineering Consultants Pvt. Ltd. delivers these services through qualified professionals, combining standard testing practices with hands-on field expertise.
Backed by years of experience in civil engineering and construction materials testing, S K Sharma Engineering Consultants Pvt. Ltd., based in Hyderabad, has established itself as a trusted name in Non- Destructive Testing in India. Their dedicated NDT division serves a wide range of projects. from residential towers and commercial buildings to bridges, industrial floors, National highways, and heritage structures, ensuring accurate assessment and support for informed decision-making.
Range of Non-Destructive Testing Services Offered
S K Sharma Engineering provides a focused range of Non-Destructive Testing (NDT) services for concrete, conducted in accordance with IS 516 (Part 5) and relevant ASTM/BS codes. These methods are carried out using sophisticated instruments, expert protocols, and strict site supervision to ensure consistency, accuracy, and traceability in test results.
Ultrasonic Pulse Velocity (UPV) Test – IS 516 (Part 5/Section 1): 2018
The Ultrasonic Pulse Velocity (UPV) Test is used to evaluate the internal quality, homogeneity, and structural integrity of hardened concrete. It works on the principle of transmitting ultrasonic pulses through the concrete and measuring the time they take to travel a known distance. A higher pulse velocity typically indicates denser, defect-free concrete, while lower velocities may suggest the presence of internal cracks, honeycombing, or voids. The test setup includes a UPV meter, transmitter and receiver transducers, coupling gel, and a calibration rod. Depending on accessibility, the test can be performed in direct, semi- direct, or indirect modes. Surface preparation is essential to ensure proper transducer contact. Factors such as concrete moisture content, reinforcement, and age can affect velocity readings and must be considered during result interpretation.
Half-Cell Potential Test – IS 516 (Part 5/Section 2): 2021
The Half-Cell Potential Test is a non-destructive electrochemical technique used to assess the corrosion activity of steel reinforcement embedded within concrete. This method measures the electrical potential difference between the reinforcement (connected to the positive terminal) and a copper-copper sulfate reference electrode (connected to the negative terminal) placed on the concrete surface. A more negative potential reading indicates a higher probability of corrosion activity. The apparatus includes a voltmeter, reference electrode, junction box, and an electrical contact solution to ensure conductivity. Prior to testing, the concrete surface should be free of coatings, clean, and moist to allow proper electrical continuity.
Variables such as concrete moisture, cover thickness, and the presence of sealants or coatings can influence test accuracy. The Half-Cell Potential Test is widely used in condition assessment of aging RCC structures and corrosion risk mapping.
Carbonation Depth Testing – IS 516 (Part 5/Section 3): 2021
The Carbonation Depth Test determines the depth to which carbonation has penetrated a concrete element. Carbonation is a chemical reaction where carbon dioxide from the atmosphere reacts with calcium hydroxide in concrete, reducing its pH and compromising the protective layer around steel reinforcement. This test uses phenolphthalein indicator solution, which turns pink in alkaline conditions (pH > 9) and remains colorless in carbonated zones. A fresh fracture surface is required for testing, obtained through chiseling or core drilling. The indicator is applied to the surface, and the transition point between pink and colorless areas is measured using a scale to determine carbonation depth. Factors influencing the test include concrete permeability, curing quality, environmental CO₂ exposure, and concrete age. Carbonation testing is particularly useful in durability assessments and corrosion diagnostics for exposed or aging concrete structures.
Rebound Hammer Test – IS 516 (Part 5/Section 4): 2020
The Rebound Hammer Test is used to estimate the surface hardness of concrete and indirectly assess its compressive strength. It involves a spring-driven plunger impacting the concrete surface, with the rebound distance (rebound number) recorded as an indicator of surface hardness. Higher rebound numbers typically correlate with higher compressive strength, although calibration is essential. The test equipment includes the rebound hammer itself, a grinding stone for surface preparation, and a standard steel anvil for calibration checks. Testing involves selecting a clean, dry, and smooth area of concrete (avoiding edges or reinforcements), applying the hammer perpendicular to the surface, and recording rebound values at multiple points. An average is taken to improve accuracy. Factors such as surface texture, moisture content, aggregate type, concrete age, and carbonation can significantly influence results. To improve reliability, site-specific correlations must be established between rebound numbers and compressive strength based on core sample testing.
Core Extraction and Compression Testing (Semi Destructive tests)
Although not classified as a non-destructive technique, concrete core extraction remains a critical validation tool for confirming the results of NDT methods. Core samples are drilled from existing structures and tested in the laboratory to determine their actual compressive strength under standardized conditions. This method is particularly valuable in establishing calibration charts for rebound hammer readings or for confirming strength in critical structural zones. Core extraction also allows for visual inspection of internal flaws, material separation, and micro-cracking, and is often combined with chemical and petrographic analyses when investigating concrete durability or mix compliance.
Comprehensive Concrete Assessment
S K Sharma Engineering acknowledges that each non-destructive testing method offers distinct insights into the condition of concrete structures, but individually they may not provide a complete picture.
Techniques such as Ultrasonic Pulse Velocity, Rebound Hammer, Half Cell Potential, and Carbonation Depth are effective for specific parameters like internal quality, surface hardness, corrosion potential, and durability. To ensure a more comprehensive assessment, the company adopts a multi-method approach by combining tests that complement one another. For example, UPV and Rebound Hammer are jointly used for improved strength estimation, while Half Cell Potential and Carbonation Depth together help assess corrosion risk and service life. When required, these methods are further supported with core extraction and laboratory analysis to validate findings. This integrated testing strategy enables S K Sharma Engineering to deliver accurate, reliable evaluations that support structural health monitoring, rehabilitation planning, and long-term durability assessments.
Technical Strengths and Service Delivery Model
The firm’s strength lies in its field expertise and ability to provide on-site NDT solutions across varied structural conditions. Their team performs preliminary assessments, conducts diagnostic testing, and delivers detailed interpretive reports that highlight risk areas, material inconsistencies, and potential remedial actions.
Every project is executed with:
- Project-specific testing plans
- Real-time data capture and documentation
- Certified and regularly calibrated instruments
- Root-cause focused evaluation
- Repair and rehabilitation input if required
Their field teams are trained in handling construction sites, existing structures, and inaccessible areas, ensuring thorough investigation even under challenging environments.
Why Choose S K Sharma Engineering for NDT Services?
- Decades of collective team experience in structural testing and material diagnostics
- End-to-end support from field investigation to certification
- Integration with project quality control teams and civil contractors
- Independent reporting for clients, consultants, and regulatory bodies
- Lab-backed analysis for sample testing, validation, and documentation
Whether for new construction QA/QC, structural health monitoring, or restoration projects, S K Sharma Engineering consultants brings a high level of technical credibility, operational flexibility, and service transparency to every assignment. With a strong focus on customer service, the team continues to adopt the latest NDT technologies to improve its service offerings. Emphasis on quality, accuracy, and timely reporting ensures right structural evaluations .
For more details;
SK SHARMA ENGINEERING CONSULTANTS PVT LTD
A-15/1/A, Road No.1, Moula Ali industrial park, Hyderabad-500040
Email: lab@sksharma.co.in
Website: www.sksharma.co.in
