| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. MEASUREMENT SETUP & INSTRUMENTS | |||
| A1 | Measurement points established: Mid-span primary; quarter-span, three-quarter-span secondary; support settlement reference point Acceptance: Mid-span = L/2; Secondary = L/4 & 3L/4; Reference point at support; Locations marked on member | Cl. 3 — Measurement point selection | OK NC NA HOLD |
| A2 | Measuring instruments: LVDT (Linear Variable Differential Transformer) with ±0.1mm accuracy or precision dial gauges (±0.05mm) Acceptance: Instrument accuracy ±0.05-0.1mm; Calibrated within 12 months; Cert provided; Data logger available if LVDT | Cl. 4 — Instrument specification | OK NC NA HOLD |
| A3 | Reference frame established: Stable independent structure (not connected to test member) to suspend measurement instruments Acceptance: Reference frame not affected by member movement; Frame level (±2mm); Position locked during test | Cl. 5 — Reference stability | OK NC NA HOLD |
| A4 | Measurement contact points: Clear, level surfaces provided on member (plywood pads glued, or steel points); accessible for probe contact Acceptance: Contact surfaces smooth, level; Pads (20×20mm min) glued with epoxy; Probes can contact repeatably | Cl. 6 — Contact surface preparation | OK NC NA HOLD |
| B. PRE-MEASUREMENT VERIFICATION | |||
| B1 | Initial deflection from self-weight estimated: Using design formulas (δ_sw = 5×DL×L⁴/(384×E×I) for simple span) Acceptance: Theoretical δ_sw calculated; Design E & I used; Compared later against measured | Cl. 7 — Initial deflection estimate | OK NC NA HOLD |
| B2 | Allowable deflection limit identified: L/250 for live load (serviceability), L/180 for total (SLS) per IS 456 Cl. 23.2 Acceptance: Live load limit = L/250; Total limit = L/180; Calculated in mm; Reference provided | Cl. 8 — Deflection criterion | OK NC NA HOLD |
| B3 | Long-term deflection multiplier considered: Creep factor λ=1+(1.6×Δf_c')/(1+50×ρ') per IS 456 Cl. 23.2, if long-term assessment done Acceptance: If long-term: λ calculated; Multiplied to immediate deflection; Final deflection = immediate × λ | Cl. 9 — Creep consideration | OK NC NA HOLD |
| C. DEFLECTION MEASUREMENT PROCEDURE | |||
| C1 | Zero reading taken: All measurement instruments set to zero at initial unloaded state; recorded as baseline in log Acceptance: All gauges/LVDTs read zero; Support settlement also zeroed; Recorded in test log with time | Cl. 10 — Baseline establishment | OK NC NA HOLD |
| C2 | Measurements taken: At multiple load levels (0%, 25%, 50%, 75%, 100% of design/test load); at least 5 data points per member section Acceptance: Multiple load steps used; Measurements at each step; Wait 2-3 min between steps for stabilization | Cl. 11 — Load step measurements | OK NC NA HOLD |
| C3 | Measurement frequency: Mid-span measured at every increment; quarter-span & support at each major increment; time recorded for creep analysis Acceptance: Complete data set at each load level; Time stamp for each reading; Minimum 3 replicates per point | Cl. 12 — Measurement frequency | OK NC NA HOLD |
| C4 | Temperature recorded at start, middle, and end of test: Changes >5°C can affect measurements; noted in report Acceptance: Temperature monitored; Variation <5°C preferred; If >5°C, thermal strain estimated and deducted | Cl. 13 — Environmental control | OK NC NA HOLD |
| C5 | Post-unloading recovery measured: Member allowed to recover for 24h; final deflection recorded to assess elastic vs. permanent strain Acceptance: Recovery measured at 1h, 4h, 24h post-unload; % recovery calculated; Should be >80-90% elastic | Cl. 14 — Elastic recovery | OK NC NA HOLD |