Saturday, February 13, 2010

Chip Seal, Rip Rap . . .

. . . Versus Slurry Seal

Chester Trczinski was working one very hot Summer morning years ago at the edge of curvy hillside Lime Street in Adams, Massachusetts, when I was out scouting with my Speed Graphic for some scenic pictures for the newspaper.

Chet and a road department crew had laced the edge of the curve with heavy rocks, set in place very carefully like a stone wall except forming a vee type trough and were pouring thin steaming hot oil over the rocks, letting it seep in between the cracks of the rock construction.

As a still young newspaperman, I was learning the secrets of old timers who labored in the hills building streets and roads that outlasted the harsh elements of a New England winter, the oldtime farmers' secrets of building dry walls of stone without mortar, and other ancient construction secrets.

I am going to try to TIE together the connection between the chip seal and slurry seal methods which is the topic of this blog. Bear with me.

Now don't think the spelling of Chet's last name is wrong; believe me, it is OK. He was a Polish decendant with a trade handed down from his great-grandfather, a trade Chet, now deceased, has passed along to some of the young whippersnappers who today, now as oldtimers, probably staff that road department.

"What are you doing on this curve with all the rocks and the oil?" I asked Chet, the road department superintendent, and immediately got an explanation of the building of roads in Poland.

The rocks, he said, used in the fashion I was seeing, comprise what is known as riprap, still used today in the Army Corps of Engineers in dam-building and river control.

The hot oil is slurry, Chet explained. "We heat it up real hot and pour it into the cracks between the stones and when it drys we add some more all over the rocks and then when it rains, or snow melts, the runoff goes downhill without eating away the edge of the curve."

Fast forward now 50 years to Hobbs.

One very hot August day outside my home here in Hobbs when the local street department was renewing the road past my place, I talked with one of the crew.

Using a big tank truck with many steel nozzles leading from the tank, the crew was spreading thick hot oil along the street. Then behind the tank truck came dump trucks loaded with small stones, backing up as the stones cascaded onto the hot thick oil. A street roller followed the trucks, pressing the stones into the oil.

Notice I keep saying hot thick oil whereas in Adams I just referred to the oil as thin hot oil. Up there on Lime Street the oil was very thin but still very hot and Chester Trczinski called it slurry sealing.

In Adams in the 1960s they didn't use a big tank truck for anything in road building. The oil was heated in a small square oven-type contraption on wheels, pulled behind a rickity dump truck.

The oil was heated by a fire of oak wood under the oven. When small stones were used to finish the slurry sealing job, or surface roads, it was done by hefty men pushing wheelbarrows, and heavy rollers made of steel drums filled with cement to anchor the stones in the oil.

"So this is slurry sealing to TIE the little stones together, right?" I commented, gaining a quick "naw, this is chip seal; what's slurry seal mean?"

Now I became, I think, not as the Irishman I am, but as a teacher with a Polish background, explaining what Chet long ago had taught me about how to TIE road work together.

Somehow, though, I think the guy I was talking to probably knew what the procedure was and was tolerating my "old geezer " knowledge just to please me.

Be it chip sealing in Hobbs or slurry sealing in Adams, the result is pretty much the same, good pavement that lasts a long time. And that's my construction instruction for tonight.

- 30 -


  1. Learn something old everyday! That's the way to keep alive the skills needed in the future.

  2. Old Newsie,

    Pretty good observations. Here is your trivia question for the day: What do you get when you apply a slurry seal over a chip seal? Its known as a Cape Seal after its extensive use in Cape Town South Africa. I understand the City of Hobbs recently started using hot applied asphalt chip seals. Most agencies are now using asphalt emulsions in New Mexico as their asphalt binder when applying chip seals or as the asphalt binder in Slurry Seals. You may find our website and the videos of both treatments at We have plants throughout the Southwest with one in Roswell, New Mexico a stones throw from Hobbs.

    Wade Miller