REBOUND HAMMER TEST: The only video you need to understand this Non Destructive Test

Every site engineer uses the Rebound Hammer Test — but 90% of people use it the wrong way. In this video I cover the complete procedure as per CPWD specifications, what the readings actually mean, and the acceptance criteria — everything that genuinely matters on site. The Rebound Hammer (Schmidt Hammer) is the fastest non-destructive test (NDT) for estimating concrete strength by measuring surface hardness. But if you ignore surface condition, angle, edge distance, or moisture — the reading will lie to you. In this video I draw on 12+ years of site experience to cover everything the manufacturer's manual doesn't tell you: ✅ How the Rebound Hammer works (why there's no rebound on soil but high rebound on steel) ✅ Where this test fits in CPWD — when it's ordered and when it's valid ✅ Step-by-step site procedure — surface prep, the 100mm thickness rule, perpendicular positioning, 12 readings ✅ Angle correction (practical use of the IS 13311 Part 2 table) ✅ How to correlate a reading to actual concrete strength ✅ CPWD acceptance criteria — when it's full payment, when it's reduced rate, when it's rejected ✅ Carbonation, cement type, aggregate, age — the 6 factors that affect your reading ✅ Documentation and the site register — so your payment isn't held up during QCTA/CTE inspection If you're a site engineer, junior engineer, or government exam aspirant — this one video will give you complete clarity on the rebound hammer. 📚 RELATED CODES & REFERENCES: IS 13311 (Part 2) | CPWD Specifications 2019 Vol. 1 💬 Have you ever used a rebound hammer on site? Tell me your experience in the comments — which reading once confused you? #ReboundHammerTest #NDTTest #CivilEngineering #SchmidtHammer #ConcreteTest #CPWD #IS13311 #SiteEngineer #CivilEngineering #ManasDey #basiccivilengineering 👷 ABOUT THIS CHANNEL: I'm Manas Dey — a civil engineer with 12+ years of experience. Here I create practical, no-nonsense content on construction site execution, CPWD specifications, material testing, and government exam preparation (SSC JE, GATE, ESE). Not theory — site reality. For querries, contact me at : manasdey.cpwd @gmail.com For civil engineering related content in instagram join me at:   / civilengineer_manas   Join my other channel for vlogs: / @manas_dey watch my other contents All about IES    • IES( Upsc Engineering services)   all about CPWD    • CPWD Related   Career awareness    • Career awareness   basics of civil engineering:    • Basics of civil engineering   Chapters 0:00 Introduction 0:46 About rebound hammer 1:06 Principle of rebound hammer working 1:51 Rebound hammer test utility 2:42 When rebound hammer test is done 3:20 1st Steps for test- surface preparation 4:16 How to read rebound hammer data in the instrument 5:14 Site demo 6:49 Precautions while doing rebound hammer 8:22 Acceptance criteria for rebound hammer test 9:17 Factors which affect rebound hammer test