Concrete stitching helps preserve the driving surface

By Priscilla Peterson,
Public Affairs Manager, Southeast Kansas 

KDOT maintenance crews from Independence and Altoona recently took advantage of some mild winter days to perform a preservation activity called concrete stitching on sections of U.S. 400 in Montgomery County. 

The process is used to pin cracks in the driving pavement back together, preventing elevation and separation issues in concrete slabs.

To stitch the pavement, first a crew member measures the crack and paints locations that will be drilled at an angle to the crack. The painted spots are then drilled and cleaned.

Steel pins are placed alongside each drilled location, and epoxy is applied to each hole before the rebar pin is inserted.

Each pin is placed at a 35-degree angle to the crack and hammered into the hole.

Pin securely placed, more epoxy is applied and the hole is smoothed over.

The stitched section is now ready for crack sealing, as shown in a previously stitched and sealed location next to the work zone. And now, on to the next section! 

A 'pawesome' story: KDOT crews rescue lost cat

Ron O’Neal was the first to hear the meow.

Equipment Operator Seniors Jorge Alvarado, Ryan Hunter and Ron O'Neal, shown left to right, helped get this cat out of a hole they were going to fill with concrete while working on the apron of a bridge at K-96 and Rock Road. They work out of the Wichita East Subarea shop

The Equipment Operator Senior and other members of the Wichita East Subarea crew were working on the apron of a bridge at K-96 and Rock Road, about to fill a hole with concrete. They stopped when O’Neal heard the plea for help.

This grey and white cat was saved by KDOT crews from Wichita.
He was reunited with his family. 

Equipment Operator Senior Ryan Hunter “sprang into action and dug him out of the hole,” Supervisor Ted Coleman said. “The hole was huge and required flowable fill. Ryan reached down about 3 feet to retrieve the kitty cat.” 

Coleman called Wichita Animal Control and took the cat home for the weekend, introducing him to his two dogs. It wasn’t the first time Coleman has gone above and beyond for animals. He once crossed four lanes of I-135 to rescue a dog that had been lost for several days. Coleman was recently featured in the #IAMDKOT series which illustrates that scene here: 

Workers at the Wichita Animal Shelter, which is situated next to the Kansas Humane Society, successfully scanned the cat for a microchip.

Turns out the kitty had been missing for a month and lived 12 miles away in Andover.

“The family was thrilled and excited to hear the good news,” Coleman said.

#ThrowbackThursday: How roads were built in 1953

Crews work on U.S. 50 outside of Strong City in 1953. 

It’s #ThrowbackThursday and in today’s blog we are going back 64 years ago to 1953.

Larry Thompson, KDOT’s Director of Operations said in this picture crews are constructing concrete pavement by placing the concrete in steel forms and using a site mixer at the paver to deliver the batches of concrete.

“This method would have required a lot of hand labor to prepare the subgrade, set forms before paving and then remove the forms and reset the forms for the next placement,” Thompson said.

We’ve come a long way since 1953, and thanks to the development of automatic machinery, crews can now “auto” trim the subgrade material and place the concrete with a slip form paver. Concrete is now delivered to the pavers by dump truck as well.

“This paver eliminated the need to set and remove forms, thus reducing the labor and increasing the speed of the operation,” Thompson said. “Grade control is now off a string line that guides the automatic equipment through each phase and helps to create a smooth driving surface and uniform thickness for strength.”

The development of larger machines has also aided in the way roads are built. Many of the machines are now controlled by electronic sensors that speed the process along, while at the same time providing uniformity and increased production. This allows the contractor to provide a quality project in less time and at a cheaper cost.

Remember when you are driving in work zones to slow down and stay alert. 

KDOT explores use of Kansas volcanic ash in concrete

Pop Quiz: When you are walking on a sidewalk are you walking on cement or concrete?

If you answered concrete, you are correct.

Concrete is the result of cement mixed with aggregate, sand and water.  Cement is the binder that hold everything together.

In an effort to explore using alternative materials in concrete, KDOT’s Bureau of Research explored the possibility of using Kansas volcanic ash as a supplementary cementitious material, or SCMs. SCMs are materials other than cement that are used to bind the mixture to create concrete.  A popular SCM is fly ash which is a waste product of coal. Because industries are switching to natural gas, coal isn’t being used as often and subsequently, a reduction in fly ash is the result.

KDOT primarily uses fly ash in KDOT concrete projects and bridge decks to improve strength and permeability characteristics.

At one time, the Rocky Mountains were volcanic and erupted sending ash into parts of Kansas. Because the ash is still present, KDOT decided to test the ash to see if this was a local resource that could be used.

Unfortunately, the report found that Kansas volcanic ash is not a viable substitute,

“Testing indicated that Kansas volcanic ash has few cementitious properties and as a result, when added to concrete, it has several possible negative effects, including increased bleed, increased set time, negative effect on strength, permeability, and finishing,” the report said.

Rick Kreider, Bureau Chief of the Bureau of Research, said that although Kansas volcanic ash is not an option for a SCM, the in-house research project was still a success because KDOT found that using this substance would not be a suitable solution. 

Image source: http://cornerstonemag.net/