HelonicHelonic

Concrete inspection checklist

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.

1
Formwork alignment and dimensions
Verify forms match drawing dimensions within ACI 117 tolerances (±1/2" for walls, ±3/8" for slabs)
2
Formwork bracing and shoring
Check that shores are plumb, braced, and sized per shoring plan; verify re-shoring for multi-story pours
3
Form release agent applied
Confirm bond-breaker is applied to all form surfaces to prevent concrete adhesion and surface damage
4
Reinforcing steel placement
Verify bar sizes, spacing, and lap splices match structural drawings; check bar supports and chairs
5
Rebar cover and clearance
Minimum cover per ACI 318: 3" for earth contact, 1.5" for exposed to weather, 3/4" for interior slabs
6
Embedded items installed
Anchor bolts, embed plates, sleeves, inserts, and blockouts placed per drawings and templates
7
MEP sleeves and penetrations
Verify all pipe sleeves, conduit stubs, and floor drains are installed, braced, and at correct elevations
8
Waterstop placement
Check waterstop is centered in joint, continuous through intersections, and properly spliced
9
Dowels and construction joints
Verify dowel size, spacing, projection length, and that previous pour surface is clean and prepared
10
Subgrade/substrate preparation
For slabs on grade: compacted subbase verified, vapor barrier installed, gravel layer in place
11
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.

1
Slump test (ASTM C143)
Test each truckload; typical range 4-6" for pumped concrete. Reject loads outside spec tolerance (usually ±1")
2
Air content test (ASTM C231)
Required for exterior exposed concrete; typical range 4-7% for freeze-thaw resistance
3
Concrete temperature
Per ACI 305/306: max 95°F for hot weather; min 50°F for cold weather. Adjust with ice or heated water
4
Cylinder samples taken
Minimum one set (typically 4 cylinders) per 150 CY or per day of pour, whichever is more frequent
5
Consolidation/vibration
Monitor vibrator insertion points, max spacing of 1.5x vibrator radius; avoid over-vibrating (causes segregation)
6
Placement height
Free-fall should not exceed 5 feet to prevent segregation; use tremie or elephant trunk for deep pours
7
Pour rate monitored
Verify placement rate matches formwork design pressure; excessive rate can cause blowouts
8
Cold joint prevention
Each lift must be placed within initial set time of previous lift (typically 60-90 minutes depending on mix)
9
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.

1
Curing method initiated
Begin curing immediately after finishing; wet cure for 7 days minimum per ACI 308, or apply curing compound
2
Curing compound application
Apply at rate per manufacturer (typically 200-300 sf/gallon); do not apply if subsequent coatings are planned
3
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
4
Surface defect documentation
Photo-document honeycombing, bug holes, cold joints, and form tie holes within 24 hours of stripping
5
Cylinder break results
Review 7-day and 28-day compressive strength results against specified f'c values
6
Crack mapping
Document any cracking: location, length, width, and pattern. Cracks over 0.012" width may require evaluation
7
Post-tension stressing
For PT slabs: stress at specified concrete strength (typically 3,000-3,500 psi), record elongation measurements
8
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
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

Keep exploring

Related references and guides for concrete inspection and structural drawings.

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.

Inspect drawings before you inspect the pour

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