Related to Pavement
Case Study: Denver Concrete Pavement Cracking Due to Thermal Stress (2020)
Project Overview
- Name: I-70 Mountain Corridor Reconstruction
- Location: Denver, Colorado
- Year: 2020
- Project Size: $750 million
- Scope: Concrete pavement reconstruction in mountainous region
- Lead Agencies/Contractors: Colorado DOT
Category of the Issue, Problem, or Challenge
- Concrete Pavement
- Thermal Stress Cracking
Summary of the Issue, Problem, or Challenge
During curing, high thermal gradients caused random cracking across large pavement panels, attributed to temperature differentials between the concrete surface and interior.
Root Cause Analysis
| Factor | Details |
| Concrete Mix | High cement content and low slump increased heat of hydration. |
| Ambient Conditions | Large diurnal temperature swings in mountain environment. |
| Lack of Thermal Control | No use of cooling techniques or joints to relieve stress. |
Impacts Due to the Issue, Problem, or Challenge
- Early cracking required surface repairs and joint resealing
- Project delays to evaluate and redesign curing procedures
- Increased long-term maintenance costs anticipated
Corrective Actions Taken
- Modified mix designs to reduce heat of hydration (e.g., using fly ash)
- Implemented night pours and cooling pipes in critical zones
- Increased joint spacing and introduced contraction joints strategically
Lessons Learned
- Thermal stresses in concrete require special design and curing strategies in extreme climates
- Mix design must consider heat generation and ambient conditions
- Proactive thermal management prevents early cracking
Case Study: Philadelphia Concrete Pavement Scaling (2019)
Project Overview
- Name: I-95 Rehabilitation
- Location: Philadelphia, Pennsylvania
- Year: 2019
- Project Size: $400 million
- Scope: Concrete pavement rehabilitation with overlay and repairs
- Lead Agencies/Contractors: Pennsylvania DOT
Category of the Issue, Problem, or Challenge
- Concrete Pavement
- Surface Durability
Summary of the Issue, Problem, or Challenge
After initial curing and exposure to freeze-thaw cycles, extensive surface scaling was observed on the concrete pavement, jeopardizing long-term durability.
Root Cause Analysis
| Factor | Details |
| Air Entrainment | Inadequate air content below specifications. |
| Deicing Chemicals | Excessive use of salts accelerated scaling. |
| Curing Duration | Insufficient curing time before exposure to harsh weather. |
Impacts Due to the Issue, Problem, or Challenge
- Partial removal and replacement of scaled sections
- Increased maintenance and repair costs
- Delays due to rework and additional testing
Corrective Actions Taken
- Strict monitoring and control of air entrainment in concrete mix
- Adjusted construction schedule to allow adequate curing before winter
- Adoption of salt-tolerant concrete mixtures and sealers
Lessons Learned
- Air entrainment is critical to freeze-thaw durability of concrete pavement
- Construction scheduling must consider seasonal weather impacts
- Deicing practices influence pavement longevity and must be managed
Case Study: Houston Concrete Pavement Joint Sealant Failure (2022)
Project Overview
- Name: SH-249 Expansion
- Location: Houston, Texas
- Year: 2022
- Project Size: $280 million
- Scope: Concrete pavement widening and rehabilitation
- Lead Agencies/Contractors: Texas DOT
Category of the Issue, Problem, or Challenge
- Concrete Pavement
- Joint Sealant Failure
Summary of the Issue, Problem, or Challenge
Shortly after joint sealing, widespread joint sealant debonding and loss occurred, allowing water infiltration and early joint deterioration.
Root Cause Analysis
| Factor | Details |
| Sealant Material | Use of substandard or incompatible sealant for local conditions. |
| Surface Preparation | Insufficient cleaning and drying of joints prior to sealant application. |
| Installation Practices | Sealant applied in adverse weather (high humidity, rain). |
Impacts Due to the Issue, Problem, or Challenge
- Early joint deterioration requiring resealing and patch repairs
- Increased maintenance workload and costs
- Project reputation impact and contractual disputes
Corrective Actions Taken
- Switch to higher performance, locally tested sealants
- Revised surface preparation protocols, including mandatory drying times
- Improved weather monitoring and restrictions for sealant installation
Lessons Learned
- Joint sealant selection must consider environment and compatibility
- Proper surface prep and installation conditions are critical for longevity
- Quality control during sealing is essential to prevent premature failure
Case Study: Chicago Concrete Pavement Low Strength (2016)
Project Overview
- Name: Lake Shore Drive Reconstruction
- Location: Chicago, Illinois
- Year: 2016
- Project Size: $350 million
- Scope: Full-depth concrete pavement replacement
- Lead Agencies/Contractors: Illinois DOT
Category of the Issue, Problem, or Challenge
- Concrete Pavement
- Strength Deficiency
Summary of the Issue, Problem, or Challenge
Core samples revealed concrete strength significantly below design requirements, necessitating removal and replacement of large pavement areas.
Root Cause Analysis
| Factor | Details |
| Mix Proportioning | Errors in batching leading to incorrect water-cement ratio. |
| Quality Control | Inadequate testing frequency and delayed test results. |
| Contractor Oversight | Lack of supervision during concrete delivery and placement. |
Impacts Due to the Issue, Problem, or Challenge
- Major project delays due to rework
- Cost overruns from additional materials and labor
- Increased risk of long-term pavement performance issues
Corrective Actions Taken
- Strengthened mix design verification and trial batching
- Increased frequency and timeliness of on-site testing
- Enhanced contractor supervision and QA/QC protocols
Lessons Learned
- Precise mix control is essential for achieving target strength
- Rapid testing feedback is necessary for corrective actions
- Contractor and QC communication must be clear and effective
Case Study: Phoenix Asphalt Pavement Rutting and Premature Distress (2019)
Project Overview
- Name: Loop 101 Freeway Expansion
- Location: Phoenix, Arizona
- Year: 2019
- Project Size: $350 million
- Scope: Asphalt pavement widening and rehabilitation
- Lead Agencies/Contractors: Arizona DOT
Category of the Issue, Problem, or Challenge
- Asphalt Pavement
- Rutting and Distress
Summary of the Issue, Problem, or Challenge
After initial opening, significant rutting developed in several asphalt lanes, alongside cracking and surface deformation, leading to ride quality complaints and safety concerns.
Root Cause Analysis
| Factor | Details |
| Mix Design | Inadequate binder grade not suited to high temperatures. |
| Construction | Improper compaction and insufficient layer thickness in some sections. |
| Traffic Loading | Underestimation of heavy truck traffic during design. |
Impacts Due to the Issue, Problem, or Challenge
- Early maintenance required including milling and overlay
- Increased costs and schedule delays
- Loss of public confidence and contractor penalties
Corrective Actions Taken
- Revised mix designs with higher PG binder grade for heat resistance
- Enforced stricter compaction testing and acceptance criteria
- Updated traffic load assumptions for design recalculations
Lessons Learned
- Binder grade selection must consider regional climate and traffic
- Field compaction monitoring is critical to prevent rutting
- Realistic traffic loading projections impact pavement performance
Case Study: New York Asphalt Pavement Rutting Due to Inadequate Compaction (2017)
Project Overview
- Name: Brooklyn Bridge Approach Roadway
- Location: New York City, New York
- Year: 2017
- Project Size: $275 million
- Scope: Asphalt overlay and reconstruction
- Lead Agencies/Contractors: New York State DOT
Category of the Issue, Problem, or Challenge
- Asphalt Pavement
- Compaction Failure
Summary of the Issue, Problem, or Challenge
Within months, rutting appeared in multiple asphalt lanes, attributed primarily to insufficient compaction during construction.
Root Cause Analysis
| Factor | Details |
| Equipment | Use of underpowered rollers not suited for layer thickness. |
| Process | Inconsistent compaction effort and lack of density monitoring. |
| Temperature | Placement of mix at lower than recommended temperature reduced workability. |
Impacts Due to the Issue, Problem, or Challenge
- Rework and additional overlays required
- Project delays and increased costs
- Negative impact on pavement service life projections
Corrective Actions Taken
- Specification revisions requiring higher compaction standards
- Implementation of nuclear density testing during rolling
- Training of paving crews on mix temperature management
Lessons Learned
- Proper compaction equipment and techniques are vital for pavement durability
- Real-time density testing allows early intervention
- Mix temperature affects compaction success