Construction Red Flags April 17, 2018 William (Clay) Herndon, P.E. - - PowerPoint PPT Presentation

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Construction Red Flags April 17, 2018 William (Clay) Herndon, P.E. - - PowerPoint PPT Presentation

Construction Red Flags April 17, 2018 William (Clay) Herndon, P.E. 1 General Site Management & Safety Site Safety Site Specific PPE Hard Hat, Safety Glass, Vest What does the Contractor provide? Safe working environment


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SLIDE 1

Construction Red Flags

April 17, 2018 William (Clay) Herndon, P.E.

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SLIDE 2

General Site Management & Safety

  • Site Safety

– Site Specific PPE

  • Hard Hat, Safety Glass, Vest

– What does the Contractor provide?

  • Safe working environment for inspection
  • Training to consider

– Site Safety – Trench Safety – Confined Space – Fall Protection – Concrete – Nuclear Gauge – Coatings

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SLIDE 3

General Site Management & Safety

  • Site Management

– Clean Site – Safe Site – Construction Materials and Debris – Positive Drainage – Labels on bags – Recyclables in Trash (LEED)

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Who’s Responsible?

  • What is Quality Assurance?

– Also know as verification testing – Also known as acceptance testing – Paid for by Owner (or under Engineer’s Contract)

  • What is Quality Control?

– Testing done by contractor for their own process control – Paid for by contractor

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SLIDE 5

Earth Work “Construction Red Flags”

  • Is the Proper Equipment in Use?

– Large Equipment in Tight Areas

  • Thickness of Lifts Being Placed
  • Use the “Heel” Test
  • Material Type in Use

– Sand – Clay – Stabilized

  • Soil Moisture
  • Color Changes
  • Organics Debris

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SLIDE 6

Formwork & Rebar “Construction Red Flags”

  • Concrete Reinforcing

– Size of Bar – Spacing – Lap

  • Projection from Foundation

– Corner Bars – Clearance – Tie Pattern – Cleanliness – Accessories

  • Chairs
  • Bolsters

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SLIDE 7

Formwork & Rebar “Construction Red Flags”

  • Concrete Reinforcing

– Confirm Spacing at Doors – Verify Proper Adhesive is Being Used – Verify Rebar is not Torch Cut

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SLIDE 8

Formwork & Rebar “Construction Red Flags”

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SLIDE 9

Formwork & Rebar “Construction Red Flags”

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SLIDE 10

Concrete “Construction Red Flags”

  • Pre-Placement

– Pre-Placement QC Inspection Complete? – Does the Contractor Have the Appropriate Equipment? – Is there a Contingency Plan in Place? – Is Water Stop Installed Properly? – Is Curing Compound/Blankets Onsite? – Are Construction Joints Installed Properly? – Is the Desired Finish Approved?

  • Placement

– Is the Contractor…..

  • Monitoring Time to Placement?
  • Monitoring Batch Times?
  • Monitoring Vibration Cycles?
  • Monitoring Consistency of Mix?
  • Monitoring Placement Method?

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SLIDE 11

Concrete “Construction Red Flags”

  • Placement

– What to Look For…..

  • Batch Tickets for Batch Time and Mix Design Number
  • Batch Tickets for Added Water
  • Contractor is Using an Approved Method of Placement
  • Formwork and Rebar is Secure During Placement
  • Time to Placement and Time to Placement Between Lifts
  • Hanging forms are Removed in a

Timely Manner

  • Post-Placement

– Curing Methods are Being Followed – Once Formwork is Removed….

  • Look for Signs of Cold Joints
  • Honey Combs
  • Desired Finish is Achieved

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SLIDE 12

Concrete “Construction Red Flags”

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SLIDE 13

Coatings “Construction Red Flags”

  • Quality Control Program

– Does your Contractor Have a QC Program? – QC Program Should Include

  • Procedures
  • Follow SP Guidelines
  • Testing Procedures
  • Pre-Application

– Confirm QC Procedures in Place – Confirm Appropriate Equipment is Onsite – Confirm QC Plan will Accommodate for Instances of Inclement Weather or Equipment Failure

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SLIDE 14

Coatings “Construction Red Flags”

  • Surface Prep

– Verify Approved Material is Being Used

  • Application

– Verify QC Program is Followed – Verify Applicator is Using QC Equipment

  • Wet Mil Gauge

– Application is Even and There are No “Runs” Present – Stripe Coat Applied to Edges – Verify Coating is Applied Adequately

  • Post-Application

– Test Coating

  • Dry Mil Gauge
  • Spark Test/Holiday Testing

– Lessons Learned – Revisit Coatings Prior to Completing a Work Activity

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SLIDE 15

Coatings “Construction Red Flags”

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Stored Materials “Construction Red Flags”

  • Handling of Materials

– Per Spec and Manufactures Recommendations – Use Proper Equipment with Proper Means of Transporting Material – Limit Number of Time the Material is Handled

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Stored Materials “Construction Red Flags”

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Pipeline “Construction Red Flags”

  • Trench

– Trench widths: Minimum and maximum – Trench height: Minimum and maximum

  • Embedment/Backfill

– Place between pipe and trench, not on top – Improper material used – “Placing” vs. “Dumping “ – Compaction of embedment

  • Handling

– Non-abrasive slings or belts – No forklifts or rolling off trailer – Crane vs other equipment

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Pipeline “Construction Red Flags”

  • Compactors

– Right equipment for the space – Dual wheel mounted on a track hoe – Jumping Jack (9-12 inch wide space) – Flat plate vibrating compactors – Pneumatic Compactors

  • Fine graded aggregate max lift

~12inches, can achieve 95% density

  • Good in tight spaces, especially the

haunches

  • Compaction

– Max lift (Spec and material type) – Testing Frequency – Moisture

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SLIDE 20

Pipeline “Construction Red Flags”

  • Nuclear Gauge

– Typical of testing the lifts of embedment material between the sidewall of the pipe and the trench wall – For tight areas, the Troxler gauge must be adjusted with a trench off- set or sidewall correction factor – The technician must be trained to enter this correction factor before starting measurements – The trench wall acts as a rebounding surface and returns more electrons to the gauge than normal causing readings to be skewed and show higher density than actual

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Pipeline “Construction Red Flags”

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Pipeline “Construction Red Flags”

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Pipeline “Construction Red Flags”

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SLIDE 24

Pipeline “Construction Red Flags”

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