A comprehensive checklist for pre-pour, during-pour, and post-pour concrete inspections

Concrete placement is one of the most critical and irreversible construction activities. Once poured, correcting defects is extremely costly — rebar can't be repositioned, embeds can't be moved, and structural capacity is set. A thorough inspection at each phase prevents costly rework and ensures the as-built structure matches the structural engineer's design intent.

Industry Data: According to the Concrete Reinforcing Steel Institute, rebar placement errors account for approximately 30% of structural concrete deficiencies. Pre-pour rebar inspection is the single most effective quality control measure for concrete construction.

Pre-Pour Inspection Checklist

Complete all pre-pour checks before any concrete is placed. These items require sign-off from the inspector and, for structural elements, the structural engineer's representative.

Formwork alignment and dimensions

Verify forms match drawing dimensions within ACI 117 tolerances (±1/2" for walls, ±3/8" for slabs)

Formwork bracing and shoring

Check that shores are plumb, braced, and sized per shoring plan; verify re-shoring for multi-story pours

Form release agent applied

Confirm bond-breaker is applied to all form surfaces to prevent concrete adhesion and surface damage

Reinforcing steel placement

Verify bar sizes, spacing, and lap splices match structural drawings; check bar supports and chairs

Rebar cover and clearance

Minimum cover per ACI 318: 3" for earth contact, 1.5" for exposed to weather, 3/4" for interior slabs

Embedded items installed

Anchor bolts, embed plates, sleeves, inserts, and blockouts placed per drawings and templates

MEP sleeves and penetrations

Verify all pipe sleeves, conduit stubs, and floor drains are installed, braced, and at correct elevations

Waterstop placement

Check waterstop is centered in joint, continuous through intersections, and properly spliced

Dowels and construction joints

Verify dowel size, spacing, projection length, and that previous pour surface is clean and prepared

Subgrade/substrate preparation

For slabs on grade: compacted subbase verified, vapor barrier installed, gravel layer in place

Pre-pour meeting completed

Review pour sequence, cold joint locations, concrete mix, finish requirements, and curing plan

During-Pour Inspection Checklist

These checks occur throughout the concrete placement. The testing laboratory should be on-site for the duration of the pour to perform required quality tests.

Slump test (ASTM C143)

Test each truckload; typical range 4-6" for pumped concrete. Reject loads outside spec tolerance (usually ±1")

Air content test (ASTM C231)

Required for exterior exposed concrete; typical range 4-7% for freeze-thaw resistance

Concrete temperature

Per ACI 305/306: max 95°F for hot weather; min 50°F for cold weather. Adjust with ice or heated water

Cylinder samples taken

Minimum one set (typically 4 cylinders) per 150 CY or per day of pour, whichever is more frequent

Consolidation/vibration

Monitor vibrator insertion points — max spacing of 1.5x vibrator radius; avoid over-vibrating (causes segregation)

Placement height

Free-fall should not exceed 5 feet to prevent segregation; use tremie or elephant trunk for deep pours

Pour rate monitored

Verify placement rate matches formwork design pressure; excessive rate can cause blowouts

Cold joint prevention

Each lift must be placed within initial set time of previous lift (typically 60-90 minutes depending on mix)

Water addition restricted

No water shall be added to truck beyond initial batch ticket; field addition voids mix design certification

Post-Pour Inspection Checklist

Post-pour inspections begin immediately after finishing and continue through the curing period and form stripping.

Curing method initiated

Begin curing immediately after finishing; wet cure for 7 days minimum per ACI 308, or apply curing compound

Curing compound application

Apply at rate per manufacturer (typically 200-300 sf/gallon); do not apply if subsequent coatings are planned

Form stripping timing

Per ACI 347: walls/columns 12 hrs min; slabs 3-7 days; beams/joists 7-14 days depending on span and loading

Surface defect documentation

Photo-document honeycombing, bug holes, cold joints, and form tie holes within 24 hours of stripping

Cylinder break results

Review 7-day and 28-day compressive strength results against specified f'c values

Crack mapping

Document any cracking: location, length, width, and pattern. Cracks over 0.012" width may require evaluation

Post-tension stressing

For PT slabs: stress at specified concrete strength (typically 3,000-3,500 psi), record elongation measurements

Patch and repair

Address defects per approved repair procedure; structural repairs require engineer approval

Common Concrete Deficiencies

Honeycombing

Cause: Insufficient vibration or too-stiff mix

Severity: Structural — requires engineer evaluation

Cold Joints

Cause: Delay between lifts exceeding initial set

Severity: Structural — reduces shear capacity

Segregation

Cause: Excessive free-fall height or over-vibration

Severity: Structural — weakens concrete matrix

Surface Scaling

Cause: Premature finishing, poor curing, or freeze-thaw

Severity: Aesthetic/durability — may need resurfacing

Plastic Shrinkage Cracks

Cause: Rapid surface evaporation before curing

Severity: Durability — allows moisture infiltration

Low Break Strength

Cause: Added water, wrong mix, or inadequate curing

Severity: Structural — may require core testing or removal

Related Guides

How to Read Structural Drawings

Understand structural plans and details.

Structural Abbreviations

Decode structural engineering abbreviations.

Concrete Mix Design Basics

Understand mix components, strength classes, and specifications.

Construction Joint Types

Complete reference for expansion, control, and isolation joints.

Concrete Rebar Clash Prevention

Avoid rebar conflicts with MEP penetrations.

Automated Foundation Review

AI-powered structural drawing analysis for concrete work.

Automate Drawing-Based Inspection Planning

Helonic's AI can extract rebar schedules, embed locations, and pour sequences from structural drawings — helping you build inspection checklists tailored to each specific pour.

Try Automated Drawing Review

Sources

ACI 318-19 — Building Code Requirements for Structural Concrete

ACI 301-20 — Specifications for Concrete Construction

ACI 117-10 — Specification for Tolerances for Concrete Construction

ACI 308R-16 — Guide to External Curing of Concrete

Concrete Inspection Checklist for Construction