Three people wearing hard hats oversee a mixture of concrete as it pours from a metal container into a wooden container. — Sara Sadat Teyebi (right) and Mohammad Jobaer Uddin (center) oversee a concrete mixture as it pours. The team was testing how the concrete mixture reacted to a stress test at the Bert Cooper Civil Engineering Laboratory in Stillwater.

CEAT researchers focused on finding right mixture for concrete runways

Thursday, January 23, 2025

Media Contact: Tanner Holubar | Communications Specialist | 405-744-2065 | tanner.holubar@okstate.edu

When it comes to concrete surfaces, airports provide unique challenges for the right type of mixture to ensure the runways can sustain the impact of landing aircraft.

Runways are prone to foreign object debris (FOD), which results in damage to runways and aircraft. FOD consists of loose materials, including broken parts of a runway that get sucked into engines causing complications.

According to a report published by the Federal Aviation Administration in May 2023, the global cost of repairs to aircraft and runways from FOD was $22.7 billion.

Dr. Tyler Ley, a professor and concrete expert in the College of Engineering, Architecture and Technology’s School of Civil and Environmental Engineering, is the principal investigator for an FAA project titled “Developing Concrete Paving Operations for Airport Runways.” Dr. Joshua Li, also a professor in CIVE, is the co-principal investigator.

Mohammad Jobaer Uddin, a Ph.D. candidate and Sara Sadat Tayebi, a Ph.D. student, are the lead students on the project. They work alongside undergraduate civil engineering and electrical engineering students who are developing sensors to be used in testing concrete mixtures.

This is the second FAA project Ley’s team has participated in. The first focused on the concrete mixture design and developing tools to evaluate the properties necessary for successful paving.  

The second project focuses on how the concrete is paved and how that process affects the quality of runways. 

Ley said one of the unique problems with concrete runways is sliver spalling, when cracks or slivers appear in the concrete. When this happens, it means the concrete had some kind of deficiency and the issue occurs at a joint or crack. 

The team has worked toward the goal of developing a concrete mixture that can minimize the issues that arise with traditional concrete mixture methods used for runways.  

The goal for the first project was to produce a new mix design method for runways, which is designed to ensure high-quality performance. The ideal concrete mix must be responsive to vibration for optimal compaction, resistant to edge slumping and have a minimized mortar layer thickness. 

A man wearing a hoodie uses a shovel to move around concrete in a metal cylinder. — Mohammad Jobaer Uddin uses a shovel to move around concrete after it was mixed with a variety of addivites to be test the stress of the mixture.

“Each of these properties provides specific benefits,” Tayebi said. “These include densification, better finish ability and excellent ride quality.”

When runways deteriorate, they can contain fragments that range in size from pebbles to broken slabs, causing damage to aircraft engines and tires. Uddin said to address this issue, critical parameters for runway pavement performance were identified and guidance was developed for the mixture design and aggregate proportions.  

“Several tools have been created to evaluate the properties of paving concrete and assess its performance,” Uddin said. “Additionally, quality control tools have been developed, including one for uniformity, which we have filed a patent application for.” 

The second project studied the best ways to pave a runway to help minimize potential hazards. Quality control testing and monitoring help ensure high construction standards are kept and the quality of the runway is ensured.  

However, creating consistent concrete runways is challenging when working on an active airfield. To help meet those challenges, the CEAT team aims to create a concrete mixture specification that can help minimize the risks of runways damaging aircraft due to FOD-related issues.  

Tools will be developed to monitor paving runways in real-time, such as monitoring vibration from equipment and the smoothness of the surface being laid.  

While it is a major concern of the FAA, there have not been specific requirements made to ensure consistency with concrete. The Department of Defense has strict guidelines, but they are difficult for contractors to meet, and pavement damage can be identified too late in the project to be fixed. Both organizations are looking closely at how the paving operations affect the quality of the runway and seek tools for early detection of pavement problems.  

“The FAA recognizes the challenges of inconsistent concrete delivery during airfield pavement construction, especially in active airfield environments,” Uddin said. “However, they have not set specific requirements for paver operation. Decisions about whether to slow down or stop the paver during delivery delays are left to the contractor’s discretion.”