Case Study: Concrete Quality Control Failure on I-70 Reconstruction (Missouri, 2017)

Project Overview
• Name: Interstate 70 Reconstruction
• Location: St. Louis, Missouri
• Year: 2017
• Project Size: $400 million
• Scope: Reconstruction of highway pavement and bridges
• Lead Agencies/Contractors: Missouri Department of Transportation (MoDOT) /

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

Summary of the Issue, Problem, or Challenge
Poorly mixed and cured concrete resulted in early cracking and spalling on bridge decks, necessitating partial demolition and replacement during construction.

Root Cause Analysis

• Inadequate control of concrete mix proportions and batching procedures.
• Failure to maintain proper curing conditions on site.
• Insufficient quality assurance checks during concrete placement.
• Lack of training for site personnel on concrete handling best practices.

Impacts Due to the Issue, Problem, or Challenge

• Delay of 5 months for remedial works and extended curing times.
• Increased material and labor costs.
• Reduced confidence from stakeholders and public about durability.

Corrective Actions Taken

1. Updated mix design and batching quality control protocols.
2. Instituted stricter curing condition monitoring and enforcement.
3. Increased frequency of on-site quality assurance inspections.
4. Conducted training sessions for all concrete handling personnel.

Lessons Learned

• Concrete quality control is essential to long-term structural integrity.
• Proper curing conditions must be consistently maintained.
• Training and supervision reduce human error in concrete works.

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

• Are mix designs verified and controlled strictly?
• Is curing monitored and enforced?
• Are personnel trained on concrete quality procedures?