Case Study: QC Failure in Asphalt Overlay on Interstate 70 Rehabilitation (Missouri, 2017)

Project Overview
• Name: I-70 Highway Rehabilitation
• Location: St. Louis, Missouri
• Year: 2017
• Project Size: $400 million
• Scope: Asphalt pavement overlay and structural repairs
• Lead Agencies/Contractors: Missouri Department of Transportation (MoDOT) /

Category of the Issue, Problem, or Challenge
• Quality Control
• Materials

Summary of the Issue, Problem, or Challenge
Non-uniform compaction and temperature control during asphalt overlay led to premature rutting and surface defects.

Root Cause Analysis

  • Inadequate temperature monitoring of asphalt mix during placement.
  • Poor compaction techniques and insufficient roller coverage.
  • Lack of real-time quality control and feedback mechanisms.
  • Insufficient training for paving and QC crews.

Impacts Due to the Issue, Problem, or Challenge

  • Delay of 2 months due to corrective milling and repaving.
  • Additional costs for materials and labor.
  • Reduced pavement service life and increased maintenance needs.

Corrective Actions Taken

  1. Installed temperature sensors and monitoring systems during asphalt placement.
  2. Improved compaction procedures with detailed roller coverage plans.
  3. Enhanced QC real-time data collection and crew feedback.
  4. Conducted training sessions focused on asphalt paving best practices.

Lessons Learned

  • Temperature control during placement is crucial for asphalt quality.
  • Thorough compaction and monitoring prevent early failures.
  • Real-time QC and crew training improve pavement outcomes.

Audit & Prevention: Project Control Questions to Ask on Future Projects to Help Control the Situation

  • Is asphalt temperature monitored and controlled continuously?
  • Are compaction techniques documented and verified?
  • Are paving and QC crews trained in best practices?
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