Rebound Hammer Test — NABL Accredited | Jancy Labs
NABL Accredited Laboratory (Certificate No. TC-12176) as per ISO/IEC 17025:2017
Your structural audit or quality inspection report needs a rebound hammer test result — and your approving authority will not accept it from a non-NABL lab. Jancy Labs conducts rebound hammer testing per IS 516 Part 5 Sec 4 with reports signed by a qualified Materials Engineer.
Jancy Labs conducts rebound hammer testing per IS 516 Part 5 Sec 4, with reports signed by a qualified Materials Engineer and NABL stamp TC-12176 — accepted at every approval desk. Get your rebound hammer test done today →
What Is a Rebound Hammer Test?
The rebound hammer test tells you the surface hardness and estimated compressive strength of an existing or newly cast concrete element — without cutting or damaging the structure.
Structural engineers and building auditors use this test to quickly screen columns, beams, slabs, and walls for quality compliance on active project sites.
Skipping this test on a rehabilitation or quality audit project means your structural assessment report lacks the IS 516-compliant data that CPWD and TNHB specifically require for approval.
Applicable Standards
Jancy Labs conducts rebound hammer testing strictly as per the following standard:
IS 516 Part 5 Sec 4
Specifies the exact procedure for rebound hammer testing of hardened concrete, including number of readings, surface preparation, and result interpretation. Jancy Labs follows IS 516 Part 5 Sec 4 without deviation — consequently, every report we issue is fully defensible at audit or approval stage.
Governing Standard in Tamil Nadu
No ASTM equivalent is applicable for this test scope. IS 516 Part 5 Sec 4 is the governing standard for all government department submissions in Tamil Nadu. Our accreditation scope is verifiable on the NABL India portal → under Certificate TC-12176.
Why This Test Matters
Specifically, the rebound hammer test delivers project consequences far beyond a simple number on a page:
- Structural audits require it — CPWD and TNHB mandate IS 516 Part 5 Sec 4 compliant rebound hammer data for existing-structure rehabilitation approvals. Furthermore, missing this data stalls your submission entirely.
- Quality control on new pours — Contractors use rebound hammer readings to verify concrete surface hardness before form stripping. Consequently, early detection of weak zones saves costly rework.
- Tender and DPR documentation — PWD Tamil Nadu and CMDA require rebound hammer test data in Detailed Project Reports for structural interventions. Therefore, you need a NABL-signed report, not a site observation note.
- MES and BRO defence projects — Military Engineering Services and Border Roads Organisation accept only NABL-accredited NDT reports for structural assessment. Additionally, non-NABL results are rejected outright at their quality audit stage.
- Smart Cities and ULB retrofitting — Urban local body projects funded under Smart Cities missions require NDT reports from accredited labs to satisfy central government audit requirements. Moreover, rebound hammer data feeds directly into structural fitness certificates.
- Insurance and litigation support — In building failure investigations, rebound hammer test data from a NABL-accredited lab carries legal evidentiary weight. Non-accredited data, however, is routinely dismissed.
⚠️ Submitting rebound hammer data from an uncalibrated or non-NABL instrument voids the result entirely and exposes you to tender disqualification. View all concrete testing services →
Why Choose Jancy Labs for Rebound Hammer Testing?
At Jancy Labs, our Schmidt hammer is NABL-calibrated to IS 516 Part 5 Sec 4 — so your rebound number stands up at every approval desk.
- Calibrated Schmidt rebound hammer — serviced and verified against NABL calibration standards.
- Rebound hammer test conducted strictly per IS 516 Part 5 Sec 4 — minimum 9 readings per test area, outliers discarded per standard.
- Every rebound hammer report signed by an Authorized Engineer.
- NABL accredited lab — TC-12176 | ISO 17025:2017.
- NHAI, Railways, AAI, CPWD, TNHB, and PWD Tamil Nadu accept our rebound hammer reports for structural audits and rehabilitation projects.
- Trusted for rebound hammer testing by structural consultants, contractors, and government project engineers across Tamil Nadu.
How to Get Your Test Done
Send Your Sample or Schedule On-Site Testing
The rebound hammer test requires testing directly on the concrete surface — on the structure itself or on extracted concrete cores at our Madurai laboratory. Therefore, most rebound hammer assignments involve our team visiting your site.
We Test It
Our Materials Engineer selects the test grid on your concrete element and marks the rebound hammer test positions as per IS 516 Part 5 Sec 4. Subsequently, we record a minimum of 9 rebound readings per test area, discard values deviating more than 6 units from the median, and calculate the average rebound number.
You Receive Your Certified Report
By courier or collect directly from us. All Government Departments accept this report for structural audit and rehabilitation submissions.
On-Site Testing — What We Need From You
| Item | Requirement |
|---|---|
| Scope confirmation | Number of elements, test locations, structural element types |
| Surface condition | Clean, dry, free of loose material — we advise on preparation |
| Access | Safe scaffolding or access platform for elevated elements |
| Site address | Share exact location and site contact before mobilisation |
Our Rebound Hammer Test Process — as per IS 516 Part 5 Sec 4
Preparing for the Rebound Hammer Test
- First, our Materials Engineer reviews the structural drawing and identifies all test locations per your project scope.
- Next, we clean the concrete surface — removing paint, laitance, or loose material — to ensure hammer contact meets IS 516 Part 5 Sec 4 requirements.
- Then, we mark a minimum 9-point test grid on each element, spaced at least 25 mm apart and 25 mm from any edge.
Finalising the Rebound Hammer Results
- Subsequently, our engineer presses the Schmidt hammer perpendicular to the surface and records each rebound number — repeating across all marked grid points.
- Next, we discard any reading that deviates more than 6 units from the median value, as IS 516 Part 5 Sec 4 specifies.
- Then, we calculate the average rebound index from the remaining valid readings.
- Consequently, we correlate the average rebound number to estimated compressive strength using the IS 516 correlation chart applicable to your cement and aggregate type.
- Finally, a qualified Materials Engineer reviews every rebound hammer result, interprets the findings against your concrete grade, and signs the report before we dispatch it.
Frequently Asked Questions
How long does a rebound hammer test take at Jancy Labs?
Can I send samples by courier to Jancy Labs for a rebound hammer test?
Is your rebound hammer test report accepted by CPWD, NHAI, Railways, AAI, PWD?
Do you conduct rebound hammer testing on existing structures and new construction?
How many readings do you take for a rebound hammer test?
Ready to Commission Your Rebound Hammer Test?
Your structural audit or quality report needs IS 516 Part 5 Sec 4 compliant data — and your approving authority will only accept it from a NABL-accredited lab. Send your requirement today and receive a quote within 24 hours.
| Contact | Details |
|---|---|
| 📞 Phone | +91-8680049004 / +91-9994421275 |
| +91-8680049004 | |
| ✉️ Email | jancylabsmdu@gmail.com |
| 📍 Address | No.6, Ganesh Nagar 3rd Street, K.Pudur, Madurai — 625007 |
| 🕐 Hours | Monday to Saturday, 10:00 AM – 6:00 PM |
Request Your Rebound Hammer Test
Share your site scope and our team will call you back with a quote within 24 hours.
Standards & Authority Reference Sources
- Bureau of Indian Standards (BIS) — official publisher of IS 516 (Part 5/Sec 4): Hardened Concrete — Non-Destructive Testing, Rebound Hammer Method.
- National Accreditation Board for Testing and Calibration Laboratories (NABL) — verify Jancy Labs' accreditation scope under Certificate TC-12176.
- Central Public Works Department (CPWD) — structural audit and rehabilitation requirements for government buildings.
- National Highways Authority of India (NHAI) — structural assessment requirements for bridges and highway structures.
- Indian Railways — NDT requirements for railway structure condition assessment.
- Airports Authority of India (AAI) — structural fitness assessment requirements for airport infrastructure.
- Smart Cities Mission — urban local body retrofitting and structural audit documentation requirements.